Backend Engineer (Python)

🏢 Summary: The offer is for a Backend Engineer role focused on building and scaling resilient backend systems and AI-driven platforms for global clients. You will work in small, autonomous teams, design production-grade architectures, and integrate Applied AI solutions into mission-critical products. The role emphasizes ownership, technical decision-making, and hands-on development using modern cloud and DevOps practices. 🗂️ Requirements: 2+ years commercial experience building web applications in Python or Ruby, Strong understanding of OOP principles, Knowledge of clean code practices, Understanding of software development lifecycle, Practical experience with SQL and relational databases, Experience with PostgreSQL, Experience with Git version control, Experience with Docker, Experience with CI/CD pipelines, Ability to integrate AI features into backend systems, Proficiency in written and spoken English 📃 Skills: Python, Ruby, PostgreSQL, SQL, AWS, Docker, Kubernetes, Git, CI/CD, OOP, Claude, Cursor 🏢 Description: Upside is a software consultancy built by engineers, for engineers. We partner with global companies to solve real, complex technical challenges. We’re deep into Applied AI and R&D, building both production-grade platforms for clients and our own open-source tools like Enthusiast (Agentic AI framework). We operate in a Forward-Deployed model. We don’t sit behind a wall of specs or wait for the tickets. We get into the trenches with the client, identify the actual challenges, and take full ownership of the solution. Our teams are small (3–9 people), autonomous, and cross-functional. What it means for you You won’t be assigned to a random project. You’ll partner directly with founders and CTOs on technical decisions, shaping systems - not just implementing them. You’ll  have the autonomy to choose  the right tools and the ownership to ensure the architecture performs under pressure.Your focus stays where it counts: mission-critical logic and high-impact experiments, not repetitive tasks and countless meetings. We don't do "safe or predictable". You’ll contribute to strategic open-source projects and build  AI-driven solutions. Role Overview As a Backend Engineer, you’ll be integral to building and scaling platforms for our global clients. You’ll join a high-performing team where your voice matters. You’ll design and implement resilient systems while staying close to the code, bringing solutions to the table instead of just reporting problems. Responsibilities Technical Execution: Build and maintain scalable backend systems with a focus on clean, maintainable code. Proactive Problem Solving: Identify issues early and propose actionable ways to fix or optimize them. Collaboration: Work closely with the team and stakeholders to translate requirements into working technology. Knowledge Sharing: Share your findings and lessons learned from the code to help the team grow. AI Implementation: Support the integration of Applied AI features into client products. Requirements Experience: 2+ years of commercial experience in building web applications (Python or Ruby). Fundamentals: Solid understanding of OOP, clean code, and software development lifecycles. Databases: Practical knowledge of SQL and relational databases (PostgreSQL). Infrastructure: Experience with Git, Docker, and CI/CD pipelines. Mindset: Proactive, curious, and ready to take ownership of your tasks. AI-Native: You use tools like Claude or Cursor to work smarter and faster. English: Great command of written and spoken English for team and client communication. Tech Stack: Python, Ruby, PostgreSQL, AWS, Docker, Kubernetes. Value Proposition Built for the long run We hire for the company, not just a project - looking for passion driven engineers who want to grow with Upside over time Small teams, real accountability. 3-9 people per engagement. We're small by design. That means your decisions carry weight and you are visible. Mission-critical work: We handle complex  projects that move the needle for international brands. Our clients are scaling companies, established international brands, and large institutions. The systems you build will be under real load, with real stakes. Real Ownership: You take part in the decision making process on technology and implementation..You’re empowered to take initiative, experiment, and drive solutions that create real impact. No Micromanagement: We trust you to own your work and deliver outcomes - no unnecessary oversight. Collaborative R&D: Contribute to targeted Open-source projects and internal AI research. Growth through challenges: Complex problems and direct client exposure means you’ll grow by action. Applied AI as a first-class discipline. We don't bolt AI onto projects as an afterthought. You'll identify where it genuinely moves the needle and lead the implementation - on client work and on our own open-source tooling. The tools you want. If something makes you faster or sharper, we want you using it. Transparent progression path. We have defined engineering levels with clear criteria - you'll know exactly what each role looks like, and what it takes to get from one to the other. No ambiguity, no waiting for someone above you to move on If you didn't find all the information you were looking for, have a look at our handbook - it covers a variety of different matters that could be important at this stage. If there's anything else we did not mention that you're interested in - share your thoughts with us careers@upsidelab.io Salary: Regular Engineer: 10 000 - 13 600 PLN net + VAT Regular+ Engineer: 14 800 - 19 300 PLN net + VAT Location: Office in Kraków, hybrid, fully-remote.

🏢 Summary: Senior Fullstack Engineer role focused on designing and scaling production-grade web systems, owning the full product experience from backend to frontend. The position combines product thinking with engineering, emphasizing AI-augmented features and modern fullstack architecture. You will work on complex, mission-critical applications with strong autonomy and technical ownership. 🗂️ Requirements: 5+ years of experience building complex web applications, Strong proficiency in Python or Ruby, Strong proficiency in Vue.js or React.js, Solid understanding of SQL and PostgreSQL, Experience with CI/CD pipelines, Experience with cloud environments, Experience using AI/LLM tools in development workflows, Fluent English (C1) 📃 Skills: Python, Ruby, Vue.js, React.js, PostgreSQL, SQL, AWS, Docker, CI/CD, Claude, Cursor 🏢 Description: At Upside , we’re partnering with ambitious companies across the globe to solve complex, meaningful problems through technology. We work in focused teams, combining engineering, product thinking, and design, to deliver outcomes, not just output. Open-source is a strategic part of our work. We build and maintain a number of open-source projects that support our clients and internal R&D. Our latest release is Enthusiast , a customizable agentic AI toolkit for e-commerce. What it means for you You’ll have a "Founder" mindset. You won’t just build a UI or a database - you’ll own the entire product experience. You’ll be a technical partner to stakeholders, helping them understand what’s possible with modern tech and AI. You’ll have the autonomy to experiment across the stack and the responsibility to deliver tools that actually solve business problems. You’ll work at the intersection of product thinking and engineering, deploying AI-augmented features across the entire stack. Role Overview As a Senior Fullstack Engineer, you’ll design and scale resilient systems from the ground up. You’ll bridge the gap between backend logic and frontend experience, ensuring a seamless, production-grade product. Responsibilities End-to-End Ownership: Lead the design and implementation of both backend systems and frontend interfaces. Proactive Solutions: Don't just flag blockers—come with proposals and experiments to bypass them. Consulting: Translate complex business needs into elegant, scalable fullstack architecture. Engineering Standards: Advocate for code quality, security, and performance across the entire repo. Continuous Improvement: Constantly evaluate new tech (especially AI/LLM) to improve delivery. Requirements Experience: 5+ years of building complex web applications. Backend: Strong proficiency in Python or Ruby. Frontend: Mastery of Vue.js or React.js . Infrastructure: Solid understanding of SQL (PostgreSQL), CI/CD, and cloud environments. AI-Native: You use tools like Claude or Cursor to build better and faster. English: Fluent (C1) for direct client collaboration. Tech Stack: Python, Ruby, Vue.js , React.js , PostgreSQL, AWS, Docker. Value Proposition Built for the long run We hire for the company, not just a project - looking for passion driven engineers who want to grow with Upside over time Small teams, real accountability. 3-9 people per engagement. We're small by design. That means your decisions carry weight and you are visible. Mission-critical work: We handle complex  projects that move the needle for international brands. Our clients are scaling companies, established international brands, and large institutions. The systems you build will be under real load, with real stakes. Real Ownership: You take part in the decision making process on technology and implementation..You’re empowered to take initiative, experiment, and drive solutions that create real impact. No Micromanagement: We trust you to own your work and deliver outcomes - no unnecessary oversight. Collaborative R&D: Contribute to targeted Open-source projects and internal AI research. Growth through challenges: Complex problems and direct client exposure means you’ll grow by action. Applied AI as a first-class discipline. We don't bolt AI onto projects as an afterthought. You'll identify where it genuinely moves the needle and lead the implementation - on client work and on our own open-source tooling. The tools you want. If something makes you faster or sharper, we want you using it. Transparent progression path. We have defined engineering levels with clear criteria - you'll know exactly what each role looks like, and what it takes to get from one to the other. No ambiguity, no waiting for someone above you to move on If you didn't find all the information you were looking for, have a look at our handbook - it covers a variety of different matters that could be important at this stage. If there's anything else we did not mention that you're interested in - share your thoughts with us careers@upsidelab.io Compensation & Location Salary: Senior Engineer: 20 800 - 25 900 PLN net + VAT Lead Engineer: >25 900 PLN net + VAT Location: Office in Kraków, hybrid, fully-remote.

🏢 Summary: Senior Fullstack Engineer role focused on designing and scaling production-grade web systems end-to-end, combining backend, frontend, and AI-driven features. The position emphasizes ownership of the full product experience, from architecture to deployment, in client-facing, mission-critical projects. Engineers work across the stack with strong autonomy, applying modern AI tools and best engineering practices. 🗂️ Requirements: 5+ years of experience building complex web applications, Strong proficiency in Python or Ruby, Advanced knowledge of Vue.js or React.js, Solid understanding of SQL and PostgreSQL, Experience with CI/CD pipelines, Experience with cloud environments, Hands-on use of AI tools such as Claude or Cursor, Fluent English (C1 level) 📃 Skills: Python, Ruby, Vue.js, React.js, PostgreSQL, SQL, AWS, Docker, CI/CD, Claude, Cursor 🏢 Description: At Upside , we’re partnering with ambitious companies across the globe to solve complex, meaningful problems through technology. We work in focused teams, combining engineering, product thinking, and design, to deliver outcomes, not just output. Open-source is a strategic part of our work. We build and maintain a number of open-source projects that support our clients and internal R&D. Our latest release is Enthusiast , a customizable agentic AI toolkit for e-commerce. What it means for you You’ll have a "Founder" mindset. You won’t just build a UI or a database - you’ll own the entire product experience. You’ll be a technical partner to stakeholders, helping them understand what’s possible with modern tech and AI. You’ll have the autonomy to experiment across the stack and the responsibility to deliver tools that actually solve business problems. You’ll work at the intersection of product thinking and engineering, deploying AI-augmented features across the entire stack. Role Overview As a Senior Fullstack Engineer, you’ll design and scale resilient systems from the ground up. You’ll bridge the gap between backend logic and frontend experience, ensuring a seamless, production-grade product. Responsibilities End-to-End Ownership: Lead the design and implementation of both backend systems and frontend interfaces. Proactive Solutions: Don't just flag blockers—come with proposals and experiments to bypass them. Consulting: Translate complex business needs into elegant, scalable fullstack architecture. Engineering Standards: Advocate for code quality, security, and performance across the entire repo. Continuous Improvement: Constantly evaluate new tech (especially AI/LLM) to improve delivery. Requirements Experience: 5+ years of building complex web applications. Backend: Strong proficiency in Python or Ruby. Frontend: Mastery of Vue.js or React.js . Infrastructure: Solid understanding of SQL (PostgreSQL), CI/CD, and cloud environments. AI-Native: You use tools like Claude or Cursor to build better and faster. English: Fluent (C1) for direct client collaboration. Tech Stack: Python, Ruby, Vue.js , React.js , PostgreSQL, AWS, Docker. Value Proposition Built for the long run We hire for the company, not just a project - looking for passion driven engineers who want to grow with Upside over time Small teams, real accountability. 3-9 people per engagement. We're small by design. That means your decisions carry weight and you are visible. Mission-critical work: We handle complex  projects that move the needle for international brands. Our clients are scaling companies, established international brands, and large institutions. The systems you build will be under real load, with real stakes. Real Ownership: You take part in the decision making process on technology and implementation..You’re empowered to take initiative, experiment, and drive solutions that create real impact. No Micromanagement: We trust you to own your work and deliver outcomes - no unnecessary oversight. Collaborative R&D: Contribute to targeted Open-source projects and internal AI research. Growth through challenges: Complex problems and direct client exposure means you’ll grow by action. Applied AI as a first-class discipline. We don't bolt AI onto projects as an afterthought. You'll identify where it genuinely moves the needle and lead the implementation - on client work and on our own open-source tooling. The tools you want. If something makes you faster or sharper, we want you using it. Transparent progression path. We have defined engineering levels with clear criteria - you'll know exactly what each role looks like, and what it takes to get from one to the other. No ambiguity, no waiting for someone above you to move on If you didn't find all the information you were looking for, have a look at our handbook - it covers a variety of different matters that could be important at this stage. If there's anything else we did not mention that you're interested in - share your thoughts with us careers@upsidelab.io Compensation & Location Salary: Senior Engineer: 20 800 - 25 900 PLN net + VAT Lead Engineer: >25 900 PLN net + VAT Location: Office in Kraków, hybrid, fully-remote.

🏢 Summary: Senior Backend Engineer role focused on designing, building, and scaling resilient backend systems for international clients, with strong ownership of architecture and technical direction. The position involves close collaboration with stakeholders, Applied AI integration, and hands-on work in small, autonomous teams. It emphasizes production-grade systems, performance at scale, and strategic technical decision-making. 🗂️ Requirements: 5+ years of experience building web applications, Proficiency in Python and Python web frameworks, University degree in Computer Science, Data Science or related field, Strong understanding of monolith and microservices architectures, Knowledge of messaging patterns, Expert-level knowledge of PostgreSQL, Experience with database performance optimization at scale, Practical experience with CI/CD pipelines, Experience with Docker and cloud platforms (AWS or GCP), Ability to design and implement scalable backend architectures, Fluent English (C1) 📃 Skills: Python, PostgreSQL, AWS, GCP, Docker, Kubernetes, CI/CD, Microservices, Monoliths, Messaging, Ruby, Claude, Cursor 🏢 Description: Upside is a software consultancy built by engineers, for engineers. We partner with global companies to solve real, complex technical challenges. We’re deep into Applied AI and R&D, building both production-grade platforms for clients and our own open-source tools like Enthusiast (Agentic AI framework). We operate in a Forward-Deployed model. We don’t sit behind a wall of specs or wait for the tickets. We get into the trenches with the client, identify the actual challenges, and take full ownership of the solution. Our teams are small (3–9 people), autonomous, and cross-functional. What it means for you You'll work with a capable and driven team, and partner directly with senior business leaders on technical decisions, shaping systems - not just implementing them. You’ll have the autonomy to choose the right tools and the ownership to ensure the architecture performs under pressure.Your focus stays where it counts: mission-critical logic and high-impact experiments, not repetitive tasks and countless meetings. You’ll contribute to strategic open-source projects and build AI-driven solutions. Role Overview As a Senior Backend Engineer, you’ll be the backbone of our development efforts and a key driver of our engineering culture. You will design, build, and scale resilient systems for international clients while staying close to the code. We’re looking for someone who brings ready solutions rather than problems to solve, and treats the client’s product as their own. This isn't a short-term opportunity  - we’re looking for a partner to grow with us, someone who thrives in a highly collaborative environment and proactively shares "lessons learned" to level up the entire team. Responsibilities Drive technical direction: Own the architecture and implementation of complex backend systems. Problem Solving: Identify systemic risks before they manifest and propose clear, actionable ways to bypass them. Consulting: Work directly with stakeholders to translate business needs into scalable technology. Mentorship: Share your observations and "lessons learned" to help the whole team level up. AI Integration: Identify where Applied AI can actually improve a product and lead the implementation. Requirements Experience: 5+ years of building web applications (preferably in Python frameworks). Background: Completed university degree in computer science, data science or similar field Architecture: Deep understanding of monoliths, microservices, and messaging patterns. Databases: Expert knowledge of PostgreSQL and performance optimization at scale. Infrastructure: Practical experience with CI/CD, Docker, and AWS/GCP. Mindset: Proactive, technology-driven, and ready to experiment. AI-Native: You use tools like Claude or Cursor to move faster. English: Fluent (C1) for direct client collaboration. Our Tech Stack: Python, PostgreSQL, AWS, Docker, Kubernetes. Ruby is present in some of our projects but we are Python first. Value Proposition Built for the long run We hire for the company, not just a project - looking for passion driven engineers who want to grow with Upside over time Small teams, real accountability. 3-9 people per engagement. We're small by design. That means your decisions carry weight and you are visible. Mission-critical work: We handle complex  projects that move the needle for international brands. Our clients are scaling companies, established international brands, and large institutions. The systems you build will be under real load, with real stakes. Real Ownership: You take part in the decision making process on technology and implementation..You’re empowered to take initiative, experiment, and drive solutions that create real impact. No Micromanagement: We trust you to own your work and deliver outcomes - no unnecessary oversight. Collaborative R&D: Contribute to targeted Open-source projects and internal AI research. Growth through challenges: Complex problems and direct client exposure means you’ll grow by action. Applied AI as a first-class discipline. We don't bolt AI onto projects as an afterthought. You'll identify where it genuinely moves the needle and lead the implementation - on client work and on our own open-source tooling. The tools you want, without the approval process. If something makes you faster or sharper, we want you using it. Transparent progression path. We have defined engineering levels with clear criteria - you'll know exactly what each role looks like, and what it takes to get from one to the other. No ambiguity, no waiting for someone above you to move on. Compensation & Location Location: On-site in Kraków; Hybrid; remote from anywhere in Poland with regular team on-sites. Salary: Senior Engineer: 20 800 - 25 900 PLN net + VAT Lead Engineer: >26 500 PLN net + VAT If you’d like to understand more about how we work or read about the recruitment process in detail, feel free to explore our handbook . If something important to you isn’t mentioned - share your thoughts with as at careers@upsidelab.io

🏢 Summary: Hands-on Staff Software Engineer role focused on leading architecture and delivering AI-driven, production-grade platforms in a forward-deployed model. Combines technical leadership, direct client partnership, and deep involvement in building scalable distributed systems. Emphasizes Applied AI integration, mentorship, and ownership of technology decisions. 🗂️ Requirements: 7+ years of experience building web applications, 2+ years in a technical leadership role (Tech Lead or similar), Deep expertise in Python, Proven experience with complex, asynchronous, distributed systems, Ability to design and drive large-scale system architecture, Experience integrating AI/ML into production systems, Fluent English (C1/C2) 📃 Skills: Python, Ruby, PostgreSQL, AWS, Docker, Kubernetes, CI/CD, AI, ML 🏢 Description: Upside is a software consultancy built by engineers, for engineers. We partner with global companies to solve real, complex technical challenges. We’re deep into Applied AI and R&D, building both production-grade platforms for clients and our own open-source tools like Enthusiast (Agentic AI framework). We operate in a Forward-Deployed model. We don’t sit behind a wall of specs or wait for the tickets. We get into the trenches with the client, identify the actual challenges, and take full ownership of the solution. Our teams are small (3–9 people), autonomous, and cross-functional. What it means for you You are the technical North Star. You’ll be a peer and advisor to CTOs and founders, shaping the technical direction of their business. This is a hands-on leadership role: you’ll stay close to the code while guiding teams through massive architectural decisions. You have the mandate to choose the best tools and the responsibility to ensure technical excellence is a lived standard, not just a goal. You’ll mentor the next generation of engineers while pushing the boundaries of Applied AI. This is about scaling both systems and people. Role Overview As a Staff Software Engineer, you will guide engineering teams in delivering AI-driven solutions and production-grade platforms. You’ll balance high-level strategy with execution, ensuring that our architecture is resilient and our engineers are growing. Responsibilities Technical Vision: Drive the architecture and technology choices for large-scale, distributed systems. Strategic Partnership: Partner directly with clients and founders to co-create solutions that move the needle. Mentorship: Foster a culture of knowledge sharing and constructive feedback. Systemic Problem Solving: Anticipate technical debt and architectural risks before they impact the business. AI Leadership: Identify and implement opportunities to integrate AI/ML into client ecosystems. Requirements Experience: 7+ years of building web applications, with 2+ years in a leadership role (Tech Lead or similar). Core expertise: Deep mastery of Python. Ruby knowledge is a plus - it's present in some of our projects, but we are Python-first. Architectural Depth: Proven ability to oversee complex, asynchronous, and distributed systems. Consulting: Exceptional ability to balance technical depth with business context. AI-Native: You treat AI tooling (Claude, Cursor, and others) as a core part of your workflow, not a novelty - and you know how to multiply team velocity with it. English: Fluent (C1/C2) for high-level strategic discussions. Tech Stack: Python, Ruby, PostgreSQL, AWS, Docker, Kubernetes, CI/CD. Value Proposition Built for the long run We hire for the company, not just a project - looking for passion driven engineers who want to grow with Upside over time Small teams, real accountability. 3-9 people per engagement. We're small by design. That means your decisions carry weight and you are visible. Mission-critical work: We handle complex  projects that move the needle for international brands. Our clients are scaling companies, established international brands, and large institutions. The systems you build will be under real load, with real stakes. Real Ownership: You take part in the decision making process on technology and implementation..You’re empowered to take initiative, experiment, and drive solutions that create real impact. No Micromanagement: We trust you to own your work and deliver outcomes - no unnecessary oversight. Collaborative R&D: Contribute to targeted Open-source projects and internal AI research. Growth through challenges: Complex problems and direct client exposure means you’ll grow by action. Applied AI as a first-class discipline. We don't bolt AI onto projects as an afterthought. You'll identify where it genuinely moves the needle and lead the implementation - on client work and on our own open-source tooling. The tools you want. If something makes you faster or sharper, we want you using it. Transparent progression path. We have defined engineering levels with clear criteria - you'll know exactly what each role looks like, and what it takes to get from one to the other. No ambiguity, no waiting for someone above you to move on Compensation & Location Staff Software Engineer: 26 500- 37 000 PLN net + VAT Location: Office in Kraków, hybrid, fully-remote. If you didn't find all the information you were looking for, have a look at our handbook - it covers a variety of different matters that could be important at this stage. If there's anything else we did not mention that you're interested in - share your thoughts with us careers@upsidelab.io

🏢 Summary: Senior Backend Engineer role focused on transforming a mission-critical e-commerce domain supporting subscriptions and purchasing journeys for millions of users. The position centers on migrating a monolithic system to scalable microservices, improving performance and reliability, and shaping the future architecture of a global platform. Engineers will work with event-driven systems and modern AI tools while owning solutions end-to-end. 🗂️ Requirements: 5+ years of professional backend engineering experience, Strong experience designing and operating microservices architectures, Experience modernising legacy systems and decomposing monoliths, Solid understanding of distributed systems and scalable backend design, Commercial experience with Go, Java, Kotlin or Scala, Hands-on experience with Kafka or similar event-streaming technologies, Hands-on experience with PostgreSQL, Hands-on experience with Docker and Kubernetes, Experience with CI/CD pipelines, Practical experience using AI coding assistants (Claude Code, Cursor, Copilot or similar), Ability to review and validate AI-generated code, Comfortable owning solutions from idea to production 📃 Skills: Go, Golang, Java, Kotlin, Scala, Kafka, PostgreSQL, Docker, Kubernetes, CI/CD, GraphQL, DDD, TDD, BDD, Microservices 🏢 Description: Join a global e-commerce technology organisation serving millions of customers across multiple international markets. As a Senior Backend Engineer, you will become part of a team responsible for one of the company's most critical customer-facing domains. The platform supports customer subscriptions, plans, and purchasing journeys used daily by millions of users. This is not a maintenance role. The team is actively transforming a mission-critical domain, modernising legacy systems, reducing technical debt, and building the next generation of scalable services that will support future growth. You will play a key role in migrating core functionality from a monolithic architecture to modern microservices while helping shape the future architecture of a global platform. What You'll Do Build & Scale Core Services Design, develop, and maintain scalable backend services within a distributed microservices architecture. Build reliable systems supporting millions of customer interactions. Improve performance, reliability, and scalability across critical customer-facing services. Drive Modernisation Lead the migration of key business domains from monolithic systems to modern microservices. Reduce technical debt and improve long-term maintainability. Design solutions that support future platform growth. Shape Architecture Participate in architecture discussions and technical decision-making. Design orchestration layers supporting complex customer journeys and business processes. Help define engineering standards and best practices. Work with Event-Driven Systems Build and operate services powered by event-driven architectures. Work extensively with Kafka and real-time lifecycle events. Design resilient and observable distributed systems. Raise Engineering Standards Conduct code reviews and support other engineers through technical guidance. Promote best practices across software development, testing, deployment, and observability. Contribute to a strong culture of ownership and continuous improvement. AI-Powered Engineering Use modern AI tools and coding agents throughout the software development lifecycle. Leverage AI for onboarding, architecture exploration, implementation, testing, debugging, and productivity improvements. Apply engineering judgement to validate, verify, and safely integrate AI-generated outputs. What We're Looking For Backend Engineering Expertise 5+ years of professional backend engineering experience. Strong experience designing and operating microservices architectures. Experience modernising legacy systems and decomposing monoliths. Solid understanding of distributed systems and scalable backend design. Technical Stack Commercial experience with Go (Golang), Java, Kotlin or Scala Engineers coming from a JVM background should be open to working in a Go-driven environment. Hands-on experience with: Kafka or similar event-streaming technologies PostgreSQL Docker Kubernetes CI/CD pipelines Product & Ownership Mindset Comfortable owning solutions from idea through production. Strong problem-solving skills and ability to make technical trade-offs. Experience collaborating with product, business, and engineering stakeholders. AI Fluency Practical experience using AI coding assistants such as Claude Code, Cursor, Copilot, or similar tools. Understanding of how context, prompts, constraints, and validation influence AI-generated outputs. Ability to critically review and verify AI-generated solutions. Nice to Have Experience with subscription-based products. Experience in e-commerce environments. GraphQL knowledge. Familiarity with DDD, TDD, and BDD practices. What We Offer Opportunity to build systems used by millions of customers globally. High-impact engineering work with significant architectural ownership. International collaboration across distributed engineering teams. End-to-end ownership from idea to production. Hybrid working model (3 days per week in the Warsaw office). B2B cooperation model. 30 days of paid annual leave. Modern office located in Warsaw city centre. Continuous learning and professional growth opportunities.

🏢 Summary: Backend Engineer role focused on building production systems for AI agents, including backend services, APIs, and data pipelines for enterprise customers. The position involves designing reliable distributed systems, maintaining production services, and collaborating closely with cross-functional teams in a fully on-site Warsaw office environment. The company offers a modern AI-focused tech stack, B2B contract, stock options, and opportunities to contribute to open-source projects. 🗂️ Requirements: 3–5 years of experience building backend production systems, Strong Python skills, Understanding of distributed systems, Experience with AWS, GCP, or Azure, Knowledge of SQL and NoSQL databases, Database design experience, Security-focused approach to system design, Ability to manage projects from idea to production, Strong written and spoken communication skills, Experience using AI tools in software development, Ability to work fully on-site in Warsaw 📃 Skills: Python, AWS, GCP, Azure, SQL, NoSQL, AI, TypeScript, APIs, GitHub, Copilot, Codex, Claude 🏢 Description: Please note: This role requires working from our office in Warsaw city centre 5 days a week . This is a fully on-site position , and remote or hybrid work is not available . About us We believe that businesses are moving toward AI-powered work, and we are building a platform for this future. Many AI agents cannot handle complex business tasks. We created a platform that organizes company policies, workflows, and business knowledge into one AI data model. This helps AI agents make accurate decisions and deliver reliable results at scale. We already work with well-known enterprise customers such as Glovo, Nespresso, and HelloFresh. Our platform supports thousands of users and handles real production data. Customers trust us with important business knowledge because we provide a secure and reliable solution with SOC2, HIPAA-ready security practices, and strong integrations. Job description We are looking for a backend engineer with several years of experience who wants to take responsibility for real systems, not only complete assigned tasks. You will solve backend challenges, choose the best technical solutions, deliver new features, and support them in production. We are looking for someone with good technical skills, clear communication, and a desire to build systems that are simple, reliable, and easy to improve. You will help build production systems for AI agents, working on real problems for customers who already use our platform. The position is based in Warsaw and requires working from the office. Responsibilities Build backend services, APIs, data pipelines, and background processes for production systems. Turn business requirements into technical solutions and implementation plans. Monitor and maintain services after release, improving reliability, performance, and system monitoring. Design service interfaces and data models that fit well into the overall system. Create technical documentation and diagrams when they help the team. Work closely with product managers, frontend engineers, and platform engineers. Improve engineering processes using AI tools, automation, and better workflows. Help maintain high code quality through code reviews and design reviews. Requirements Around 3–5 years of experience building backend production systems. Strong Python skills and the ability to write clean and maintainable code. Good understanding of distributed systems, including concurrency, failures, data consistency, asynchronous processing, and service communication. Experience with cloud platforms such as AWS, GCP, or Azure, and knowledge of SQL, NoSQL, and database design. A security-focused approach when working with sensitive data and system design. Ability to manage projects from idea to production with increasing responsibility. Good written and spoken communication skills, with the ability to explain technical decisions clearly. Experience using AI tools as part of your daily software development work. Nice to have Experience with AI agents, orchestration, retrieval systems, tool calling, or LLM-based infrastructure. Knowledge of TypeScript or willingness to work across the full technology stack. Experience taking on more responsibility and learning quickly. What we offer B2B contract and company stock options. MacBook Pro. Modern technology stack and the opportunity to contribute to open-source projects. An AI-focused development environment with tools such as Claude Code, OpenAI Codex, and GitHub Copilot. Our values Our leadership team combines strong experience in AI, knowledge management, and enterprise SaaS. We have received more than $60 million in funding and have been recognized by Gartner as a Cool Vendor. Our work is guided by these values: Quality – We care about excellent work and high standards in everything we build. Momentum – We take initiative, share ideas, and keep moving forward. Accountability – We take responsibility for our work and give honest, respectful feedback. Hard work – We believe success comes from teamwork, dedication, and consistent effort. Learning agility – We stay curious, learn from mistakes, and continue improving. Adapt and thrive – We welcome change and see challenges as opportunities to grow. Win together – We work as one team, communicate openly, and support our shared goals.

🏢 Summary: Senior Backend Engineer role focused on designing, building, and maintaining production backend systems and AI-driven workflows in a fully onsite Warsaw office environment. The position involves ownership of system architecture, APIs, distributed systems, and cloud infrastructure from design through production. Candidates will collaborate across teams, improve engineering processes with AI tools, and contribute to scalable, reliable solutions. 🗂️ Requirements: Strong experience as a senior backend engineer on production systems, Excellent Python programming skills, Understanding of distributed systems, Experience with AWS or Azure cloud platforms, Knowledge of SQL and NoSQL databases, Experience with asynchronous processing and service design, Ability to design and deliver systems from idea to production, Strong written and spoken communication skills, Regular use of AI development tools, Ability to work fully onsite in Warsaw 📃 Skills: Python, AWS, Azure, SQL, NoSQL, APIs, AI, TypeScript, GitHub, Copilot, Claude, OpenAI, Codex 🏢 Description: Please note: This role requires working from our office in Warsaw city centre 5 days a week . This is a fully on-site position , and remote or hybrid work is not available . About Us Many companies want to use AI agents, but these agents often struggle with real business tasks. We solve this problem by building a platform that helps AI understand business rules, workflows, and processes. This allows AI to make better decisions and provide accurate, reliable, and compliant results. Well-known companies from different industries use our technology to automate up to 85% of customer cases, reduce handling time by 20–25%, and complete tasks that used to take hours in just seconds. We also work with leading technology partners and have been recognized for our innovative approach. Our goal is to help people everywhere get better answers through AI. Job Description We are looking for a Senior Backend Engineer who can take ownership of important systems instead of only completing assigned tasks. You will solve complex problems, design backend solutions, build them, and make sure they run well in production. We want someone with strong technical skills, good communication, and the ability to create simple, reliable, and easy-to-maintain systems. This is a product engineering role with responsibility from system design to production. The position is based in Warsaw and requires office work. Responsibilities Design and develop backend services, APIs, data processing, and background tasks for production systems. Turn unclear business needs into clear technical plans and practical solutions. Maintain services after release by improving reliability, monitoring, performance, and fixing issues. Make good decisions about system architecture, data models, interfaces, and future scaling. Write technical documentation, architecture notes, and diagrams when they help the team. Work closely with product managers, frontend engineers, and platform engineers to deliver complete solutions. Improve development processes using AI tools, automation, and internal workflows. Support the team through code reviews, design reviews, and practical technical leadership. Requirements Strong experience as a senior backend engineer working on production systems. Excellent Python skills and the ability to write clean and maintainable code. Good understanding of distributed systems, including concurrency, failure handling, data consistency, asynchronous processing, and service design. Experience with cloud platforms such as AWS, Azure, or similar services. Knowledge of SQL, NoSQL databases, schema design, and performance optimization. Ability to take a project from an idea through design and implementation to production. Strong written and spoken communication skills with the ability to explain technical topics clearly. Regular use of AI tools in everyday development and interest in improving AI-based workflows. Nice to Have Experience with LLM-based applications, search systems, AI infrastructure, or large data pipelines. Knowledge of TypeScript or the ability to contribute to frontend development when needed. Experience guiding other engineers and influencing technical decisions without being a formal manager. What We Offer B2B contract and company stock options. MacBook Pro for work. Modern technology stack and opportunities to contribute to open-source projects. Access to advanced AI development tools, including GitHub Copilot, Claude Code, OpenAI Codex, TypingMind, and MCP servers. Our Culture and Values Our leadership team has strong experience in AI and knowledge management. We have secured more than $60 million in funding and achieved three years of continuous 3x growth. Our work is based on these values: Quality – We aim for excellent work and high coding standards. Momentum – We take initiative and keep projects moving forward. Accountability – We take responsibility and give honest, respectful feedback. Hard Work – We believe great results come from teamwork and consistent effort. Learning Agility – We stay curious, learn from mistakes, and improve every day. Adapt and Thrive – We accept change and see challenges as opportunities. Win Together – We succeed as one team through honesty, openness, and support for our shared mission.

🏢 Summary: Backend Engineer role focused on building and maintaining high-volume, complex API integrations using pure Ruby in a transactional, money-flow–critical domain. The position involves designing robust backend services, ensuring reliability and transactional integrity, and collaborating with stakeholders and external partners. The environment emphasizes AWS-based infrastructure, DevOps practices, and secure, scalable solutions. 🗂️ Requirements: Strong experience with Ruby (beyond Ruby on Rails), Proven experience delivering backend services in complex domains, Expertise in API design and third-party integrations, Familiarity with transactional systems and reliability constraints, Solid understanding of DevOps practices, Experience with Infrastructure-as-Code, Hands-on experience with AWS (EC2, S3, RDS), Experience with Docker, Experience with Redis, Strong analytical skills, Clear stakeholder communication skills 📃 Skills: Ruby, Redis, Docker, AWS, EC2, S3, RDS, Infrastructure-as-Code, API, Thin, EventMachine, Sinatra, Elasticsearch 🏢 Description: Project overview This project focuses on building and maintaining high-volume, complex API integrations with external partners in a domain where transactional integrity and money flows are critical. Position overview We are looking for a Backend Engineer with strong expertise in pure Ruby. In this role, you will design and maintain robust backend services and high-volume API integrations in a domain where transactional integrity and money flows are critical. You’ll collaborate closely with stakeholders and external partners to deliver secure, scalable solutions. Technology stack Ruby (pure Ruby, not Rails-centric) Redis Docker AWS services (EC2, S3, RDS) Infrastructure-as-Code tools Responsibilities Design and implement robust backend services using Ruby Develop and maintain complex API integrations with external systems Ensure transactional integrity and reliability in high-volume environments Collaborate with stakeholders and external partners to clarify requirements Contribute to infrastructure automation and deployment processes Participate in technical design discussions and solution shaping Requirements Strong experience with Ruby (beyond Ruby on Rails) Proven track record of delivering backend services in complex domains Expertise in API design, integration, and third-party connectivity Familiarity with transactional systems and reliability constraints Solid understanding of DevOps practices and Infrastructure-as-Code Hands-on experience with AWS services (EC2, S3, RDS) Knowledge of Docker for containerization Experience with Redis Strong analytical skills for navigating intricate business rules Clear and confident communication skills for stakeholder engagement Nice to have Thin, EventMachine, Sinatra Exposure to Elasticsearch. Experience in financial or transactional domains. What We Offer: Vacation days : Up to 26 business days per year. 10 illness/special days off per year (fully paid, no medical papers needed) for all contract types Health and life insurance (Luxmed) MyBenefit platform with Multisport option Internal psychological support service English language classes from the first working day Access to external learning platforms : O’Reilly, LinkedIn Learning, Udemy, and a wide catalog of diverse internal training Flexible workplace : work from the office, from home, or choose a hybrid option Tech Skills Mentoring Program Opportunities to develop as a public speaker, mentor, or technical interviewer Fully paid idle (bench) when not involved in a project Certification reimbursement (AWS, GCP, Microsoft, etc.)

🏢 Summary: Senior or Staff Backend Engineer role focused on architecting and scaling AI-native backend systems for a modern accounting platform. The position involves designing distributed services, building high-performance APIs, and establishing engineering standards to support rapid, reliable product delivery. You will work closely with Product, AI, and Operations teams to develop agentic systems and scalable data pipelines. 🗂️ Requirements: 5–10+ years of backend engineering experience, Proven experience designing, building, and operating production backend systems at scale, Strong expertise in API design, Strong expertise in data modelling, Deep understanding of distributed systems trade-offs, Hands-on experience with AWS or GCP in production, Practical experience with CI/CD in high-frequency deployment environments, Experience implementing testing and deployment strategies, Strong knowledge of observability practices, Experience participating in on-call rotations 📃 Skills: TypeScript, Node.js, React, AWS, GCP, Terraform, PostgreSQL, OpenAI, Azure, CI/CD, APIs, DistributedSystems 🏢 Description: ABOUT THE ROLE We're looking for a Senior or Staff Backend Engineer to own and evolve our backend services as we scale. This is a broad, high-impact role — you'll architect new features, build the systems that underpin our core product, and set the engineering standards that shape how the whole team works. The focus is on building a modern, AI-native developer experience. That means working closely with Product, AI, and Operations teams to design agentic systems, distributed data pipelines, and scalable incident response infrastructure — and doing it in a way that lets the team ship with confidence multiple times a day. WHAT YOU'LL WORK ON Architecture and feature design Partner with Product, AI, and Operations teams to architect new features and complex agentic systems. Make clear architectural trade-offs that balance platform, product, and business goals. Backend services and APIs Build and maintain the backend services and APIs that power the core product. Ensure systems are secure, well-tested, and high performance. Distributed systems Design and implement distributed services to orchestrate data pipelines, automate investigations, and enable incident response at scale. Operational excellence Own operational best practices so the team can ship multiple times a day with confidence. Healthy on-call culture and strong observability are part of what you'll build and maintain. Engineering standards Set the bar for writing, communication, and system design across the team. Your influence will shape how a modern AI-native product is built. WHAT WE LOOK FOR 5–10+ years of backend engineering experience A strong track record designing, building, and operating production backend systems at scale. Deep backend fundamentals Expertise in API design, data modelling, and reasoning about distributed systems trade-offs. You understand the nuances, not just the patterns. AWS or GCP hands-on experience Solid understanding of how infrastructure decisions impact application reliability and performance. You've run things in production, not just designed them. CI/CD in practice Practical experience with testing and deployment strategies in high-frequency shipping environments. Observability and on-call maturity A solid grasp of what good observability looks like and how to build healthy on-call practices that don't burn people out. Bonus Experience at an early-stage or scaling startup. Exposure to modern AI and ML systems. Experience shipping product without a dedicated product manager. TECH STACK TypeScript, React, Node.js, AWS, Terraform, PostgreSQL, OpenAI, Azure AI. The team uses GitHub, Slack, Linear, Figma, and Notion day to day. THE TEAM Small, senior, and in-person. The office is in central Wrocław, next to the main train station. The expectation is 4–5 days a week in the office. Relocation support is available for the right candidate. COMPENSATION & BENEFITS Salary $130,000 – $190,000 USD depending on experience, plus competitive equity. Wellness and commute stipend $100 per month. Hardware Premium hardware provided — MacBook Pro and AirPods. Food Daily in-office lunch and dinner. Time off 20 PTO days plus 9 US public holidays. Relocation Support available for candidates relocating to Wrocław.