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 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: 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 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.

🏢 Summary: Full-time remote Backend Engineer role focused on building and enhancing secure PHP-based APIs for an open-source cybersecurity product. The position involves developing new features, maintaining code quality, implementing tests, and ensuring high standards of security, performance, and data integrity. The engineer will work on cryptographic mechanisms, access control, and secure API workflows used at scale. 🗂️ Requirements: 3+ years experience building PHP applications, Proficiency in CakePHP, Laravel or Symfony, Experience with PHPUnit testing, Knowledge of OpenAPI specifications, Experience with Git and branching models, Understanding of OWASP Top 10 and secure coding practices, Proficiency in at least one additional language: JavaScript, Bash, Python, Go or Rust, Experience building and maintaining secure APIs, Ability to write unit and end-to-end tests, Experience with CI/CD pipelines 📃 Skills: PHP, CakePHP, Laravel, Symfony, PHPUnit, OpenAPI, Git, OWASP, JavaScript, Bash, Python, Go, Rust, CICD, APIs, GDPR 🏢 Description: 💰 Salary: 4000 - 4500 EUR, depending on experience 🕦 Full-time ☑️ EOR 🌴 Remote We are looking for a Backend Engineer  to join a fast-growing open-source cybersecurity company's engineering team. The role focuses on building and improving secure APIs, handling data integrity, access rights management, and cryptographic mechanisms while maintaining high standards of performance, quality, and security across all product editions. Requirements 3+ years of experience building PHP applications Proficient in building back-end applications with CakePHP, Laravel, or Symfony Proficient in testing applications with PHPUnit Familiar with OpenAPI Specifications Familiar with Git and branching models Strong understanding of OWASP Top 10 vulnerabilities and secure coding practices Proficient with at least one additional programming language: JavaScript, Bash, Python, Go, or Rust Fluent in English, both verbal and written Key Responsibilities Develop new features in PHP and CakePHP for existing products used daily by over half a million users Maintain, improve, and fix bugs on the existing codebase Transform functional specifications into reliable API workflows, ensuring backward compatibility and security Participate in code reviews to identify defects before launch Write unit tests aiming for 80% coverage to ensure functionality and prevent regressions Develop end-to-end tests to ensure critical user journeys function correctly across various scenarios Optimize code for performance and scalability to handle growth and increased demand Contribute to OpenAPI specifications, SDKs, and user and admin guides Collaborate closely with SRE teams to maintain robust CI/CD pipelines Apply secure coding and design practices to ensure all components adhere to the highest security standards Monitor project dependencies for vulnerabilities and assist the security team in analyzing their impact Ensure data handled by the product development team complies with GDPR and other data protection regulations Get to know DevsData: We are a technology consulting company and a recruitment agency, delivering software solutions to clients from Europe and the US. We work 100% remotely, in an international team, including people from Asia, London, or San Francisco. We employ people with experience in international corporations as well as students of the best technical and business universities. Find out more: https://devsdata.com/

🏢 Summary: Backend Engineer role focused on building next-generation security solutions with an emphasis on secure backend systems, cryptography, automation, and AI-driven analysis. The position involves hands-on development of scalable backend services in cloud environments, contributing to architecture, APIs, and data design. You will work within a small technical team delivering secure, high-availability systems deployed in AWS. 🗂️ Requirements: 3+ years backend software engineering experience, Strong TypeScript experience, Strong Node.js experience, Hands-on AWS experience, Experience with EKS or ECS, Experience with serverless architectures, Experience with relational databases, Experience with key/value datastores, Experience with graph datastores, API design experience, Data modeling experience, Experience developing secure services, Experience writing automated tests for load and performance 📃 Skills: TypeScript, Node.js, AWS, EKS, ECS, Serverless, SQL, NoSQL, Graph, APIs, DataModeling, Testing, LoadTesting, PerformanceTesting, Cryptography 🏢 Description: Backend Engineer Poland, Remote or Ukraine, Remote or Romania, Remote Point Wild helps customers monitor, manage, and protect against the risks associated with their identities and personal information in a digital world. Backed by WndrCo, Warburg Pincus and General Catalyst, Point Wild is dedicated to creating the world’s most comprehensive portfolio of industry-leading cybersecurity solutions. Our vision is to become THE go-to resource for every cyber protection need individuals may face - today and in the future. Join us for the ride! About the Role: We’re looking for a Backend Engineer to contribute to a next-generation security initiative . You’ll be part of a small, highly technical team working on novel approaches to secure systems - with a focus on cryptography , automation, and AI-powered analysis. You’ll work closely with senior engineers and contribute hands-on to the codebase across the stack. This role involves hands-on development, learning opportunities, and collaboration across engineering, product, and design. Day to Day: Contribute to the design, development, and delivery of features across the product Write clean, maintainable code for back-end systems deployed in AWS/GCP Collaborate with AI and cryptography specialists Work with the product manager to understand requirements and help the team plan architecture, data flows, API specs, and testing strategies Follow established engineering practices and participate in team discussions around process and quality Participate in customer-driven development and iterate based on feedback Write automated tests for load, performance, and error handling What you bring to the table: 3+ years of hands-on software engineering experience for backend development Excellent TypeScript and Node.js coding experience AWS experience in containers (EKS, ECS) and serverless systems Relational, key/value, and graph datastore experience with schema management API design, data modeling, secure service development, database systems Has a focus on quality code, error handling, and high availability A thoughtful, pragmatic approach to solving technical problems in a fast-paced environment At least upper-intermediate level of spoken and written English Extra Credit: Versed in Python coding and environments Experience with Bun and Express GitHub Actions and IaC Experience with GCP systems Experience with applied cryptography, especially key management, TLS, or post-quantum algorithms Familiarity with agent-based architectures or systems that scan and orchestrate actions across distributed environments Knowledge of AI/ML systems, particularly LLM integration or agent-style reasoning patterns Experience managing LLM agents to increase both speed and quality of code generation and tests Exposure to security tools, vulnerability detection platforms, or compliance automation Prior experience working on developer-facing or infrastructure-heavy products Why Join Us? Professional Growth: Enhance your skills by collaborating closely with talented engineers and architects. Meaningful Impact: Help create software that protects millions of users from cybersecurity threats. Supportive Environment: Join a team dedicated to innovation, mentorship, and continuous learning.

🏢 Summary: Full-time Senior Back-End Engineer (Node.js) role focused on designing and maintaining scalable, high-performance server-side applications and APIs for modern, data-driven platforms. The position involves building RESTful services, integrating with third-party systems, ensuring code quality through testing, and optimizing system reliability and performance. Hybrid work model in Warsaw with B2B or CoE contract options. 🗂️ Requirements: Strong experience with Node.js, Strong experience with Express.js, Experience building and integrating APIs (GraphQL or REST), Knowledge of OAuth, JWT, and session-based authentication, Experience with MySQL, Experience with PostgreSQL, Experience writing unit tests with Chai and Mocha, Experience using Git and version control systems 📃 Skills: Node.js, Express.js, GraphQL, REST, OAuth, JWT, MySQL, PostgreSQL, Chai, Mocha, Git 🏢 Description: Senior Back-End Engineer (Node.js) 💰 Salary: 18,700-20,900 PLN/Month 💻 Warsaw, Poland (Hybrid - 3 days in office, 2 days remote) 🕦 Full-time ☑️ B2B or CoE We’re looking for a Senior Back-End Engineer to join a fast-growing international tech company focused on building modern, data-driven platforms that power digital transformation in the financial and enterprise sectors. Requirements: Strong experience in building server-side applications using Node.js and Express.js. Hands-on experience with API development and integration, particularly with GraphQL or RESTful services. Strong knowledge of authentication and authorization mechanisms (OAuth, JWT, session-based). Strong experience with databases such as MySQL and  PostgreSQL. Experience writing unit tests with tools such as Chai and Mocha. Strong experience using Git and version control systems. Proficiency in English (both written and spoken). Nice To have: Bachelor’s degree in Computer Science or a related field. Experience with cloud platforms (AWS, Azure, or GCP), as well as containerization and orchestration tools such as Docker and Kubernetes. Experience with microservices architecture. Experience setting up CI for static analysis and test execution. Experience developing RAG applications and storing data in vector embeddings. Key Responsibilities: Design, build, and maintain scalable, high-performance server-side applications and RESTful APIs using Node.js and Express.js. Guide and supervise the development of key code components to ensure long-term reliability and scalability. Integrate with front-end components and third-party services. Actively review the codebase, recommending and implementing refinements where needed. Write unit and integration tests and optimize performance to ensure high-quality code. Collaborate closely with cross-functional teams to define and implement technical solutions. Improve system performance, reliability, and long-term maintainability through optimization and best practices. Get to know DevsData: We are a technology consulting company and a recruitment agency, delivering software solutions to clients from Europe and the US. We work 100% remotely, in an international team, including people from Asia, London, or San Francisco. We employ people with experience in international corporations as well as students of the best technical and business universities. Find out more: https://devsdata.com/

🏢 Summary: Frontend Engineer role focused on building scalable, responsive web applications for a global e-commerce platform using modern frontend technologies. The position involves developing reusable UI components, collaborating with cross-functional teams, and improving frontend architecture in a fully remote environment. The offer includes a COE contract, benefits package, and opportunities for continuous technical growth. 🗂️ Requirements: Degree in Computer Science or equivalent experience, 2–4 years of commercial frontend or software engineering experience, Experience developing production web applications, Knowledge of JavaScript, Knowledge of TypeScript, Knowledge of HTML, Knowledge of CSS, Experience with React ecosystem, Experience with React Router, Experience with Vite, Webpack, or Rsbuild, Experience with Zustand, TanStack React Query, or Redux, Experience with Tailwind CSS, HeroUI, or Material UI, Experience writing unit tests with Jest and Testing Library, Familiarity with Playwright or Cypress, Understanding of reusable component development, Familiarity with Git workflows, Basic understanding of CI/CD pipelines, Experience integrating REST APIs, Basic understanding of cloud applications, Basic SQL knowledge, Ability to work in Agile teams 📃 Skills: React, TypeScript, JavaScript, HTML, CSS, ReactRouter, Vite, Webpack, Rsbuild, Zustand, TanStack, Redux, Tailwind, HeroUI, MaterialUI, Jest, TestingLibrary, Playwright, Cypress, Git, CI/CD, GitHubActions, Azure, AzureDevOps, Jenkins, REST, SQL, MySQL, PostgreSQL 🏢 Description: Position: Frontend Engineer Type of contract: COE (UoP) up to 17 000PLN gross/month Working model: fully remote You can join our client and work on a modern digital platform designed to better connect shoppers and retailers within the global e-commerce ecosystem. The project focuses on building and enhancing scalable web applications and core services that power user interactions. You’ll collaborate closely with product and design teams to deliver intuitive, high-performance user experiences. The environment emphasizes innovation, usability, and continuous improvement of frontend architecture. Role summary: As a Frontend Engineer , you will contribute to the development of modern, responsive web applications while working closely with cross-functional teams. You will be responsible for implementing user interfaces based on UI/UX designs, building reusable components, and ensuring high code quality. This role offers the opportunity to work with modern frontend technologies, collaborate with experienced engineers, and continuously develop your technical skills in a global e-commerce environment. Responsibilities: Develop and maintain modern, responsive user interfaces using React and TypeScript; Collaborate with designers, backend engineers, QA, and DevOps teams to deliver high-quality features; Translate UI/UX designs into clean, maintainable, and reusable code; Build reusable UI components and contribute to a consistent frontend architecture; Optimize application performance and improve user experience; Participate in code reviews and follow engineering best practices; Ensure cross-browser compatibility, responsiveness, and accessibility standards; Troubleshoot and resolve frontend issues while supporting continuous product improvements. Key requirements: Degree in Computer Science (or equivalent practical experience); 2–4 years of commercial experience in software engineering or frontend development; Hands-on experience in developing production web applications; Good knowledge of JavaScript, TypeScript, HTML, and CSS , with practical experience using TypeScript in commercial projects; Experience working with the React ecosystem , including React Router and modern build tools such as Vite, Webpack, or Rsbuild ; Experience with state management and data-fetching libraries such as Zustand, TanStack React Query, Redux , or similar solutions; Familiarity with modern component libraries and styling solutions such as Tailwind CSS, HeroUI, Material UI , or similar; Experience writing unit tests using Jest and Testing Library ; familiarity with E2E testing tools such as Playwright or Cypress is a plus; Understanding of reusable component development and frontend best practices; Familiarity with Git and collaborative development workflows; Basic understanding of CI/CD pipelines and release processes (GitHub Actions, Azure DevOps, Jenkins, or similar); Experience working with REST APIs and integrating frontend applications with backend services; Basic understanding of cloud-based applications; experience with Azure is an advantage; Understanding of relational databases and basic SQL knowledge (MySQL or PostgreSQL); Familiarity with monitoring and logging tools is considered a plus; Strong communication skills and the ability to work effectively within Agile teams; Proactive attitude, willingness to learn, and the ability to independently deliver well-defined features with attention to quality. Offer: COE (UoP), up to 17 000 PLN gross per month ; Private healthcare, life insurance, sports card, and lunch subsidy; Learning and development support (including tuition assistance); Employee Assistance Program; Fully remote work model supporting work–life balance; Opportunity to collaborate with experienced engineers on global-scale e-commerce solutions.

🏢 Summary: Backend Developer role in a global digital asset trading firm, working remotely on live production trading systems and infrastructure. The position focuses on backend services, exchange integrations, real-time market data processing, and reliability improvements within a small, highly technical team. It offers direct impact on trading operations and close collaboration with trading infrastructure in a crypto-focused environment. 🗂️ Requirements: Degree in Computer Science, Electrical Engineering, Software Engineering or related field, Hands-on experience with Python, C++ or another backend/systems language, Understanding of APIs, integrations and production systems, Experience with Linux and debugging, Strong problem-solving skills, Interest in trading systems, financial markets or crypto infrastructure, Very good English proficiency 📃 Skills: Python, C++, REST, WebSocket, Linux, Docker, SQL, PostgreSQL, Redis, Kafka, ClickHouse, APIs, Networking, Concurrency, Algorithms 🏢 Description: Location: 100% remote from Poland Contract: B2B Budget: 10,700–21,400 PLN net + VAT / month Seniority: Junior+ / Mid Industry: digital assets / trading systems We are supporting a global digital asset trading firm in hiring a Backend Developer to join a small, highly technical engineering team working on live production trading systems. You will be working close to trading infrastructure, exchange connectivity, real-time data, reliability, and internal tools used in a production trading environment. The company operates internationally and is now expanding its presence in Poland. What you will work on Depending on your experience and strengths, you may be involved in: building and improving backend services supporting trading operations, integrating with external APIs and crypto exchanges, working with REST / WebSocket APIs, processing real-time market data, improving reliability of production systems, debugging issues in live trading infrastructure, building internal tools and automation for trading operations, collaborating closely with a small technical team. What we are looking for We are looking for someone with strong backend or systems engineering foundations who enjoys solving technical problems and wants to work closer to trading infrastructure. You may be a good fit if you have: a degree in Computer Science, Electrical Engineering, Software Engineering or a closely related technical field , hands-on experience with Python good understanding of APIs, integrations and production systems, experience with Linux and debugging technical issues, strong problem-solving skills and ability to explain your thinking clearly, interest in trading systems, financial markets, crypto infrastructure or real-time systems, very good English - the recruitment process and daily cooperation are in English . Nice to have Any of the following would be a strong plus: experience with trading systems, market data, order books or exchange connectivity, experience with crypto, blockchain, DeFi, market-making, arbitrage or digital assets, experience with WebSocket APIs and real-time data flows, experience with low-latency, high-throughput or performance-sensitive systems, knowledge of algorithms, data structures, concurrency, networking or distributed systems, experience with Docker, SQL, PostgreSQL, Redis, Kafka, ClickHouse or similar technologies. Why this role may be interesting 100% remote setup, B2B cooperation, direct impact on live production trading systems, small technical team with strong ownership, opportunity to work close to crypto trading infrastructure, practical engineering work, not only feature delivery, environment where problem-solving, technical clarity and ownership matter. Sounds interesting? Apply and share your CV. We will contact selected candidates with more details about the company, role and next steps.