Senior Backend Engineer (Python)

🏢 Summary: Senior Backend Developer role focused on designing and delivering scalable server-side applications and APIs using Python and Django for early-stage B2B SaaS products. The position involves architectural ownership, system reliability, and performance optimization in a fully remote, full-time setup. The developer will drive backend best practices, testing, and CI/CD processes. 🗂️ Requirements: 5+ years of backend development experience, Extensive experience with Python, Extensive experience with Django, Proficiency in data modelling, Experience with relational databases, Experience with non-relational databases, Ability to write complex SQL queries, Experience with API design, Experience with system integrations, Experience with distributed systems (synchronous and asynchronous), Hands-on experience with Docker, Hands-on experience with Redis, Experience with message brokers, Experience with cron jobs, Experience writing unit tests (e.g. Pytest), Strong understanding of code quality and testing best practices, Good command of English for technical communication 📃 Skills: Python, Django, SQL, Docker, Redis, Pytest, APIs, Databases, PostgreSQL, MongoDB, CI/CD, MessageBroker, Cron, Git 🏢 Description: Senior Backend Developer (Python/Django; 100% remote) 💰 Salary: 23,400-25,500 PLN/month 🌎 100% Remote 🕦 Full-time position ☑️ B2B or Contract of Employment We are looking for a Senior Backend Developer for a partner client with a compelling mission: they act as a product and technology partner for early-stage B2B SaaS founders, helping them navigate the crucial journey from launch to their first million in revenue. They essentially become the dedicated tech backbone for these startups. Requirements: 5+ years of professional backend development experience. Extensive, proven experience with Python and the Django framework. Proficient in data modelling, relational and non-relational databases, and complex SQL queries. Strong experience with API design, integrations, and distributed systems (synchronous & asynchronous communication). Hands-on experience with Docker, Redis, message brokers, and cron jobs. Expertise in writing unit tests (e.g., Pytest) and a commitment to code quality and testing best practices. Great understanding of English with strong communication and collaboration skills. Nice to have: Previous experience in Greentech or Ecotech is a significant plus. Experience as an unofficial tech lead or mentoring junior developers. Knowledge of additional testing methodologies (integration, end-to-end). Responsibilities: Lead the design and development of complex server-side applications, APIs, and databases, taking ownership of architectural decisions. Architect, write, and deliver high-quality, scalable, and efficient code using Python and Django. Collaborate closely with cross-functional teams, including front-end developers and the tech lead, to align backend development with project goals. Architect and implement advanced user authentication, authorisation, and security mechanisms. Conduct performance analysis and optimisation, identifying bottlenecks and implementing solutions. Drive the implementation of automated testing and CI/CD processes to ensure code reliability. Establish and enforce coding standards, conduct thorough code reviews, and document backend architecture and APIs. Take responsibility for system reliability, scalability, and security, ensuring 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: 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: Full-time B2B opportunity for a Middle Python Engineer to build scalable backend systems and AI infrastructure for enterprise applications in a hybrid Warsaw setup. The role involves developing REST APIs, distributed systems, and cloud-based services while owning features through the full software lifecycle. Candidates will work in an AI-native environment focused on production-ready enterprise AI solutions. 🗂️ Requirements: 3-5 years commercial experience as Backend Engineer, Strong Python programming skills, Understanding of distributed systems, Experience with AWS, GCP, or Azure, Strong knowledge of SQL databases, Strong knowledge of NoSQL databases, Experience designing and supporting production-grade systems, Experience with full software lifecycle ownership, Ability to develop scalable backend services and REST APIs, Comfortable working in AI-native engineering environments 📃 Skills: Python, AWS, GCP, Azure, SQL, NoSQL, REST, TypeScript 🏢 Description: Python Engineer 💰 Salary: 5000-7000$ 🌎 Warsaw, Hybrid (1 day remote per week) 🕦 Full-time ☑️ B2B Contract We’re looking for a Middle Python Engineer for our client, which is an AI infrastructure company that helps large enterprises safely and effectively adopt AI in their daily operations. Rather than building general-purpose AI, our client creates a platform that connects AI to a company's internal knowledge, policies, workflows, and business rules. This enables AI to provide accurate answers and automate complex business processes instead of relying on generic responses or potentially inaccurate information. Their customers include well-known enterprise organizations such as Glovo, Nespresso, and HelloFresh, where AI is used to improve internal operations, customer support, and business efficiency. The company operates in the rapidly growing field of Agentic AI, focusing on building reliable, production-ready AI systems for enterprise environments. Requirements: 3-5 years of commercial experience as a Backend Engineer developing production-grade systems. Strong Python programming skills, with the ability to write clean, maintainable, and well-structured backend code. Good understanding of distributed systems. Hands-on experience with cloud platforms, such as AWS, GCP, or Azure. Strong knowledge of SQL and NoSQL databases, including schema and data model design. Experience owning features throughout the full software lifecycle, from design and implementation to deployment, monitoring, and production support. Comfortable working in an AI-native engineering environment. Nice to have: Exposure to agentic systems: AI agents, tool-calling, orchestration, retrieval, or LLM-backed infrastructure Working knowledge of TypeScript Responsibilities: Design, develop, and maintain scalable backend services, REST APIs, data pipelines, and background processing systems. Translate business and product requirements into technical solutions, evaluating architecture, trade-offs, and implementation approaches. Own features end-to-end, from technical design and development through deployment, monitoring, and ongoing production support. Build reliable, secure, and high-performance backend systems that support enterprise AI applications. Design efficient interfaces, data models, and service architectures that integrate seamlessly within the broader platform. Monitor, troubleshoot, and improve system reliability, observability, scalability, and performance in production environments. Collaborate closely with Product Managers, Frontend Engineers, and Platform/Infrastructure teams to deliver end-to-end product features. Write clear technical documentation, design notes, and architecture diagrams to support collaboration and knowledge sharing. Leverage AI-powered development tools to improve engineering productivity, automate repetitive tasks, and streamline development workflows. Participate in code reviews and design reviews, ensuring high engineering standards, maintainable code, and best practices.

🏢 Summary: Senior Full Stack Developer role focused primarily on backend development with Python and FAST API, combined with React-based frontend work in a hybrid B2B model. The position involves designing scalable web applications, building high-performance APIs, and working with relational and NoSQL databases. Strong backend expertise is essential, with intermediate frontend skills and experience in modern DevOps practices. 🗂️ Requirements: 8+ years of professional software development experience, Expert proficiency in Python, Strong experience with FAST API, Strong knowledge of relational and NoSQL databases, Experience with SQLAlchemy ORM, Deep understanding of data structures and algorithms, Experience building RESTful APIs and microservices, Proficiency in writing unit and integration tests in Python, Strong knowledge of ReactJS and NodeJS, Experience with Redux or MobX, Familiarity with React Query, Experience with Material UI, CSS, and HTML, Experience with Jest and Cypress, Solid understanding of JavaScript and TypeScript 📃 Skills: Python, FASTAPI, SQLAlchemy, PostgreSQL, MySQL, MongoDB, DynamoDB, ReactJS, NodeJS, Redux, MobX, ReactQuery, MaterialUI, CSS, HTML, Jest, Cypress, JavaScript, TypeScript, Docker, Kubernetes, AWS, Azure, GCP, RabbitMQ, Kafka 🏢 Description: Working mode: Hybrid mode ( 2-3 days in a week from the office in Wroclaw or Warsaw) Experience Level: 8+ Years Contract Type: B2B About the Role We are looking for a highly skilled Senior Full Stack Developer with a primary focus on Python and FAST API to join the development team. The ideal candidate is a Python expert capable of architecting robust backend services. While React skills are required, we are flexible regarding the depth of frontend expertise (Intermediate level is acceptable), provided the backend strength is exceptional. Key Responsibilities Backend Architecture: Design, develop, and maintain scalable web applications using Python and FAST API . API Development: Build high-performance RESTful APIs and microservices, ensuring low latency and high availability. Database Management: Work with relational and NoSQL databases, utilizing ORMs like SQLAlchemy to design efficient database schemas and queries. Frontend Development: Develop and maintain user-facing features using ReactJS , ensuring the technical feasibility of UI/UX designs. Code Quality: Write clean, maintainable, and testable code; perform unit testing to ensure robustness. DevOps: Implement and manage CI/CD pipelines to streamline deployment processes. Collaboration: Work closely with cross-functional teams (Product, QA, and Design) in a hybrid working environment. Mandatory Technical Skills 1. Backend (Core Strength): Languages: Expert proficiency in Python . Frameworks: Strong experience with FAST API (Must-have). Experience with SQLAlchemy is highly preferred. Fundamentals: Deep understanding of data structures, algorithms, and space-time complexity. Database: Strong understanding of Relational (e.g., PostgreSQL, MySQL) and NoSQL (e.g., MongoDB, DynamoDB) databases. Testing: Proficiency in writing unit tests and integration tests for Python applications. 2. Frontend (Intermediate Level): Libraries: Strong knowledge of ReactJS and NodeJS . State Management: Experience with React workflows such as Redux or MobX . Tooling: Familiarity with React Query . Styling: Experience with Material UI , CSS , and HTML . Testing: Experience with frontend testing tools like Jest and Cypress . JavaScript: Solid understanding of JavaScript , TypeScript , and browser rendering behavior. Good to Have Experience with cloud platforms (AWS, Azure, or GCP). Knowledge of containerization (Docker, Kubernetes). Understanding of microservices architecture and message queues (RabbitMQ, Kafka).

🏢 Summary: Senior Full Stack Software Engineer role focused on building and scaling a production-ready AI product, covering feature development, infrastructure, and client integrations. The position involves hands-on work with Python, DevOps/MLOps, and GenAI solutions, ensuring system reliability and production readiness. This is a remote contract role with expected extensions. 🗂️ Requirements: Strong Python development experience, DevOps expertise with CI/CD pipelines, MLOps experience with automated deployment and monitoring, Experience building agentic AI products, Experience with API integrations, Hands-on experience with GenAI/LLM, Ability to harden systems for production, Experience fine-tuning AI models, Experience with prompt engineering 📃 Skills: Python, CI/CD, DevOps, MLOps, GenAI, LLM, APIs, Automation, Deployment, Monitoring, Fine-tuning, Prompt-engineering 🏢 Description: Location : Remote with occasional visits to Łódź Employment type : 2 months initial contract - to be extended, B2B/Umowa Zlecenie Salary: up to 160zł/hour (B2B) Senior Software Engineer – AI Product (Full Stack) We’re looking for a Senior Software Engineer to help build and scale a production-ready AI product. This is a hands-on, full-stack role covering feature development, infrastructure, and client integration. What you’ll do Design, build, and deploy new features in Python Own DevOps/MLOps: CI/CD pipelines, automated model deployment, monitoring Integrate AI solutions into client-facing products Improve system reliability, performance, and production readiness Enhance AI models through fine-tuning and prompt engineering Contribute to short-term R&D initiatives and product innovation Build and evolve internal systems for model evaluation and performance tracking Must-have Strong Python development experience DevOps & MLOps expertise (CI/CD, automation, deployment) Experience building agentic AI products and API integrations Hands-on GenAI/LLM experience (classic ML not required) Proven ability to harden systems for production Nice to have Experience building model evaluation/monitoring systems Fine-tuning, prompt engineering, and performance optimization Details Contract extensions expected If you enjoy building real-world AI products end-to-end—from models to production—we’d love to hear from you.

🏢 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: Opportunity for a Senior Python Developer to build advanced risk management platforms for global financial institutions within demanding trading environments. The role focuses on developing scalable backend systems, contributing to cloud-based architectures, and collaborating with international clients and senior engineers. It offers high technical ownership, exposure to quantitative finance, and work across multiple modern technologies. 🗂️ Requirements: Strong commercial experience in Python backend development, Degree in Computer Science, Mathematics, Physics, or related field, Solid understanding of software architecture, algorithms, and data structures, Experience with cloud platforms (AWS, Azure, or GCP), Ability to work across multiple programming languages and tech stacks, Confident English communication skills, Willingness to work in hybrid model (4 days in Warsaw office) 📃 Skills: Python, Go, Rust, C++, TypeScript, AWS, Azure, GCP, Algorithms, DataStructures, Cloud 🏢 Description: 💎 Senior Python Developer 💎 A rare opportunity has arisen for an ambitious, highly technical Senior Python Developer to join an elite engineering team building advanced risk management solutions for global financial institutions. In this role, you will work on complex backend systems used within highly demanding financial and commodities trading environments, collaborating closely with top-tier engineers and international clients. You will contribute to the development of scalable risk platforms while working across modern cloud infrastructure and multiple programming languages. If you enjoy solving difficult engineering problems, working alongside exceptionally strong developers, and building software with real business impact… Feel invited! This role offers a unique combination of technical depth, ownership, and exposure to the world of quantitative finance. WHAT WE OFFER B2B contract Competitive salary + biannual bonus Flexible working hours Hybrid work - 4 days from the office located in Warsaw Work closely with experienced engineers from top financial and technology companies International projects and collaboration with global clients Opportunity to grow within a highly technical, developer-driven culture YOUR ROLE Develop and maintain backend systems primarily in Python Build and extend risk management software for financial institutions Design scalable and maintainable solutions for complex business requirements Collaborate directly with international clients and technical stakeholders Work across multiple technologies including Python, Go, Rust, C++, and TypeScript Contribute to cloud-based solutions running on AWS and Azure Participate in architectural discussions and technical problem solving Continuously improve platform reliability, performance, and scalability IF YOU ARE A PERSON WHO Has strong commercial experience with Python backend development Holds a degree in Computer Science, Mathematics, Physics, or a related field Has solid understanding of software architecture, algorithms, and data structures Feels comfortable working across multiple programming languages and tech stacks Communicates confidently in English and enjoys working directly with clients Has experience with cloud platforms such as AWS, Azure, or GCP Understands financial systems or has previous exposure to financial markets (nice to have) Thrives in highly collaborative, engineering-driven environments Enjoys solving complex technical challenges together with the team in the office Congrats! This offer is especially for YOU!

🏢 Summary: Senior Full Stack Product Engineer role focused on building end-to-end AI-powered product features across frontend and backend systems in a fully on-site Warsaw office environment. The position involves owning the full development lifecycle, collaborating with product and design teams, and improving performance, usability, and reliability of production applications. Engineers will work with modern AI development tools and contribute to scalable enterprise-grade solutions. 🗂️ Requirements: Senior-level experience building production web applications, Strong frontend experience with React or TypeScript, Backend experience designing APIs and backend services, Experience working across full-stack web development, Ability to improve UX and simplify workflows, Experience making technical decisions balancing scope and quality, Security-focused approach with sensitive data handling, Experience collaborating with engineering, product, and design teams, Daily use of AI tools in software development, Ability to work fully on-site in Warsaw 📃 Skills: React, TypeScript, API, Python, Node.js, AI, Claude, OpenAI, Codex, GitHub, Copilot 🏢 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 processes 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 Senior Full Stack Product Engineer who enjoys building complete product solutions from start to finish. In this role, you will understand customer needs, design the right technical solution, build new features, and improve them after release. You will work across both frontend and backend, taking ownership of the whole development process - from the first idea to production. The position is based in Warsaw and requires working from the office. Responsibilities Build and deliver product features across both frontend and backend. Turn product ideas into practical technical solutions with the right scope and priorities. Work across the full technology stack, including user interfaces, backend logic, APIs, and data flows. Work closely with product managers and designers, even when requirements are still changing. Improve usability, performance, reliability, and overall product quality. Monitor applications after release, analyze logs and system data, and continue improving the product. Use AI tools every day to improve development speed, workflows, and engineering processes. Maintain high standards for code quality, testing, and long-term ownership. Requirements Strong senior-level experience building and delivering production web applications. Strong frontend skills with React, TypeScript, or a similar modern web framework. Good backend experience designing APIs, backend services, and data flows. Strong product thinking with the ability to improve user experience and simplify complex workflows. Good judgment when making technical decisions and balancing scope, quality, and delivery time. A security-focused approach and experience handling sensitive data. Good communication skills and experience working with engineering, product, and design teams. Experience using AI tools as part of your daily software development work. Nice to have Experience building AI-powered products such as chat applications, search, recommendation systems, workflows, or AI agents. Experience with Python, Node.js, or both. Experience leading product areas with a high level of ownership. Good understanding of web performance, accessibility, and production quality. 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 has 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: 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: Senior Python Backend Developer role focused on building scalable, cloud-native backend systems using Python and FastAPI within GCP environments. The position involves designing containerized microservices, contributing to system architecture, and supporting CI/CD processes in a modern cloud ecosystem. Fully remote within Europe with collaboration on high-impact digital transformation projects. 🗂️ Requirements: Minimum 4 years of backend development experience with Python, Strong knowledge of GCP and cloud service architectures, Experience with FastAPI or similar Python frameworks, Experience with containerized environments, Solid understanding of microservices architecture, Experience designing and developing REST APIs, Proficient English (spoken and written), Legal right to work in Europe 📃 Skills: Python, FastAPI, GCP, Containers, Microservices, REST, CICD, React 🏢 Description: Ignite innovation — transform cloud-native backend solutions with Python mastery! Warszawa-based opportunity with remote work model, allowing up to 5 days per week from anywhere in Europe. As a Senior Python Backend Developer – Cloud & Container Experts , you will be working for our client, a leader in cloud computing and containerization technologies. Join a dynamic team dedicated to building scalable, resilient, and cutting-edge backend systems that power modern applications. This role offers a pathway to work on impactful projects at the forefront of digital transformation. Your main responsibilities: Design, develop, and optimize scalable backend services using Python and FastAPI within cloud environments. Implement containerized solutions leveraging Google Cloud Platform (GCP) and modern orchestration tools. Collaborate with cross-functional teams to deliver high-performance software solutions. Ensure code quality, performance, and security standards are maintained. Participate in continuous integration and deployment pipelines to streamline releases. Contribute to system architecture planning and best practices in cloud-native development. Troubleshoot and resolve production issues swiftly and efficiently. You're ideal for this role if you have: At least 4 years of experience in backend development with Python. Strong knowledge of GCP, containers, and cloud service architectures. Experience with FastAPI or similar frameworks. Previous full-stack experience is a plus; familiarity with React is advantageous. Solid understanding of microservices and RESTful API design. Ability to work independently in a remote environment and communicate effectively within international teams. It is a strong plus if you have: (optional) Additional certifications in cloud technologies or container orchestration. Experience with DevOps tools and CI/CD pipelines. Language Required for the role: Proficient command of English (spoken and written). Eligibility for the role: Only candidates with an existing legal right to work in Europe will be considered for this role. #MAKEYourCareerBETTER Interested? Apply now and include your CV (preferably in English) along with a statement confirming your consent to the processing and storage of your personal data.