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

Must-have technologies: React.js | Angular | Node.js | Java | Python | REST | Microservices | PostgreSQL | MySQL | MongoDB | Cassandra | GCP | Kubernetes | Docker | Serverless Computing | CI/CD | Infrastructure as code | Agile Methodology | Scrum MethodologyNice-to-have technologies: Alicloud | AWS | Microsoft Azure | Jupyter Notebooks | Pandas | NumPyJoin 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.Your tasksArchitect, design, and build a scalable web platform from scratch, covering both frontend and backendLead development of user‑facing features using modern frontend frameworksDevelop and maintain backend services, including APIs, microservices, data models, and business logicDesign resilient, performant architecture across databases, services, and APIsCollaborate closely with product, business, and engineering stakeholders in an Agile (Scrum) environmentEnsure high‑quality, rapid delivery through CI/CD pipelines, automated testing, and code reviewsDesign and build scalable cloud infrastructure, preferably on GCP, using infrastructure as code, containerization, and serverless solutionsMentor engineers, promote team autonomy, uphold architectural standards, and drive technical excellenceWork with both relational and NoSQL databasesRequirementsAt least 8 years of software engineering experience, including 3+ years in full‑stack roles designing, building, and launching web platformsStrong expertise in modern frontend frameworks (React, Angular, or Vue), including component‑driven architecture, state management, routing, and responsive UISolid backend experience covering RESTful APIs, microservices, domain‑driven design, scalable architectures, and fault toleranceProven ability to build platforms and tools from scratch and deliver end‑to‑end solutions under tight timelinesHigh level of autonomy: ownership of technical decisions, task management, and delivery with minimal supervisionExperience with relational (PostgreSQL, MySQL) and NoSQL (MongoDB, Cassandra) databasesProficient with Git and version control workflowsDeep understanding of architectural best practices combined with a fast‑paced, pragmatic, and results‑driven delivery mindsetAvailability to work from the Kraków office 6–8 times per monthResiding in Poland required