Tech Lead Full Stack Developer (f/m/x)

Join Sii as a Lead Full Stack Engineer, and you will build and develop a modern web platform used for risk, compliance, and business architecture management. You will work on both frontend and backend, creating solutions from end to end. The role involves close collaboration with product managers, engineers, and business users to turn complex needs into practical tools. You will also take ownership of technical decisions and support high development standards within the team. Your work will help improve automation, compliance, and data-driven decision-making across the organization.

• At least 8 years of software engineering experience, including 3+ years in full-stack roles designing, building, and launching web platforms
• Strong expertise in modern frontend frameworks (React, Angular, or Vue), including component-driven architecture, state management, routing, and responsive UI
• Solid backend experience covering RESTful APIs, microservices, domain-driven design, scalable architectures, and fault tolerance
• Proven ability to build platforms and tools from scratch and deliver end-to-end solutions under tight timelines
• High level of autonomy: ownership of technical decisions, task management, and delivery with minimal supervision
• Experience with relational (PostgreSQL, MySQL) and NoSQL (MongoDB, Cassandra) databases
• Proficient with Git and version control workflows
• Deep understanding of architectural best practices combined with a fast-paced, pragmatic, and results-driven delivery mindset
• Availability to work from the Kraków office 6–8 times per month
• Residing in Poland required

• Architect, design, and build a scalable web platform from scratch, covering both frontend and backend
• Lead development of user-facing features using modern frontend frameworks
• Develop and maintain backend services, including APIs, microservices, data models, and business logic
• Design resilient, performant architecture across databases, services, and APIs
• Collaborate closely with product, business, and engineering stakeholders in an Agile (Scrum) environment
• Ensure high-quality, rapid delivery through CI/CD pipelines, automated testing, and code reviews
• Design and build scalable cloud infrastructure, preferably on GCP, using infrastructure as code, containerization, and serverless solutions
• Mentor engineers, promote team autonomy, uphold architectural standards, and drive technical excellence
• Work with both relational and NoSQL databases

• Residing in Poland required