full-stack developer for AI-powered B2B platforms

5Blue Software is an Israeli-Ukrainian software development company specializing in custom software development, staff augmentation, dedicated engineering teams, AI solutions, and CTO-as-a-Service. We help startups and mid-sized companies scale faster with vetted engineering talent across Europe. We're looking for a Senior Full-Stack Developer who can work confidently across frontend and backend, take ownership of features from initial design to production, and contribute to architectural decisions.

• Build and deliver end-to-end features using React, TypeScript, and Node.js.
• Develop performant, scalable, and user-friendly frontend experiences for a complex B2B product.
• Design and implement backend services, APIs, business logic, and third-party integrations.
• Build and integrate AI-powered features into a production environment.
• Contribute to system design, architecture, and technical decision-making.
• Use AI-assisted development tools such as Claude Code or similar as part of your everyday workflow.
• Review, test, debug, and validate AI-generated code, ensuring you understand and take ownership of the final implementation.
• Work with relational and non-relational databases and make appropriate technical choices based on product requirements.
• Contribute to CI/CD, testing, deployment, and DevOps processes for the features you build.
• Collaborate directly with Engineering and Product to clarify requirements and develop effective technical solutions.
• Participate in Agile ceremonies and collaborate with teammates across different locations and time zones.
• Communicate your thought process clearly, explain technical decisions, and discuss trade-offs in English.

• 5+ years of professional software development experience, with approximately 5+ years of Node.js experience as a guideline. Strong hands-on expertise in a closely related stack may also be relevant.
• 2+ years of professional React experience, with a solid understanding of modern frontend development.
• Strong practical experience with TypeScript.
• Hands-on experience with Express, Fastify, or a similar API framework.
• Strong full-stack capabilities, with the ability to work independently across frontend and backend.
• Production experience with microservices architecture.
• Hands-on experience with AWS or a comparable cloud platform, such as GCP or Azure.
• Practical experience with both relational and non-relational databases, such as PostgreSQL and MongoDB, including understanding how to choose the right approach for different use cases.
• Experience integrating third-party REST APIs into production systems, beyond developing internal API endpoints.
• Experience building and shipping AI-powered features in a real product, such as AI agents, generative AI functionality, RAG-based solutions, or similar.
• Experience using AI-assisted coding tools, such as Claude Code or equivalent, as part of your regular development workflow.
• The ability to independently write, understand, debug, and validate code without relying on AI tools.
• Working knowledge of DevOps, QA, testing, and CI/CD, sufficient to manage the delivery and quality of your own features.
• English proficiency at B2 level or higher, with the ability to participate confidently in technical discussions, explain your reasoning, and justify engineering decisions in real time.
• Experience working in a product-focused engineering environment.
• Будет плюсом: Backgrounds in security, compliance, governance, or developer tools are a plus, but not mandatory; Experience with LangChain, LangGraph, or similar AI/agent frameworks; Practical Python experience alongside your primary technology stack; Experience with Docker, Kubernetes, or other containerization technologies; A degree in Computer Science, Software Engineering, or a related field; Experience mentoring other engineers or contributing to architectural and design decisions; Experience working with distributed, international Agile teams

• Remote work opportunities.
• Individual English language training.
• Comprehensive medical insurance.
• A supportive, collaborative, and dynamic international team.
• All necessary equipment supplied.
• Accounting assistance in Ukraine and Poland.
• 18 days of annual vacation and 7 sick days per year without requiring a doctor's note.
• Convenient payment options with multiple withdrawal methods.