Senior Full-Stack Engineer (AI-Driven Development)

## This is how we work - at the client's site ## Your responsibilities - Take end-to-end ownership of features across frontend, backend, databases and integrations. - Understand business requirements and translate them into robust technical solutions. - Direct, challenge and validate AI coding agents throughout the development process. - Critically review AI-generated code, identifying architectural weaknesses, security issues and quality risks. - Work confidently with relational databases, data models and enterprise application architectures. - Deliver complete features quickly while maintaining appropriate engineering standards. - Collaborate directly with solution architects and product owners. - 5+ years of experience in software engineering, developing production-grade enterprise applications. - Strong backend development skills, preferably Java/JVM. - Full-stack capabilities, including practical experience with modern frontend frameworks (React is a plus). - Strong knowledge of relational databases, SQL and data modelling. - Proven ability to independently deliver end-to-end features across frontend, backend and integrations. - Hands-on experience with AI coding tools and/or agentic development workflows. ## Optional - Experience with Microsoft Azure cloud services. - Experience with PostgreSQL/SAP integrations. - Familiarity with CI/CD pipelines and DevOps practices. - Experience with SonarQube and automated code quality tools. - Experience working on international enterprise projects. - #OneSquareOne - one team, many talents - Square One Poland specializes in IT outsourcing and supporting companies in building and scaling technology teams. We help international organizations access proven IT specialists, carefully matched to project requirements and company culture. - We act as a strategic partner, enabling effective team scaling — from individual experts to complete project teams — based on transparent cooperation and long-term, win–win relationships. For IT professionals, we offer inspiring projects delivered with modern technologies, clear communication, and real opportunities for professional growth. - Operating internationally, we combine years of experience with creativity, agility, and flexibility. Despite our market maturity, we retain a start-up DNA that allows us to respond quickly to changing business needs. - Our organizational culture is confirmed by the Great Place to Work® 2026 certification.