Expert Fullstack .NET & TS Developer

Nasze wymagania: 5+ years of experience as a .NET Developer with TypeScript Excellent development skills in C# Experience building Web APIs and backend services Good understanding of multithreading and parallelism Experience with Entity Framework and/or Dapper Experience with unit testing and mocking Good understanding of: Microservice architecture, Event-driven architecture, Git, the entire CI/CD workflow from development to release, GitHub, SQL and noSQL databases (preferably with PostgreSQL, MongoDB, Redis), .NET 6 or newer, AWS Very good English communication skills (B2+/C1) Mile widziane: Fullstack experience with React, NestJS, NextJS Experience with Node.js Knowledge of Domain-Driven Design (DDD) Experience with event-driven systems Fintech or product-company background Bachelor's degree in computer science or related studies O projekcie: Join KOIA and work on a modern fintech platform built for the Scandinavian market. We are looking for a Mid/Senior Fullstack .NET Developer to join a long-term project for our Norwegian client. The role is backend-heavy (~65%), with additional involvement in architecture, technical analysis, and frontend development using React and TypeScript. You’ll work in a collaborative engineering environment where developers actively influence technical decisions, architecture, and product evolution. Project: The application is built using modern technologies and cloud-native architecture. • Frontend: React, TypeScript z NestJS, NextJS • Backend: .NET and Node.js • Infrastructure: AWS • Architecture: Microservices, Event-driven architecture (Kafka) • Testing: Unit tests, Integration/Process tests (test containers based), E2E Tests (Playwright) • Databases: PostgreSQL, MongoDB, Redis • Cloud: AWS • CI/CD: GitHub Actions The team focuses strongly on: • code quality, • automated testing, • maintainability, • minimizing technical debt, • continuous improvement. Regular technical and architectural discussions are part of the development process, and every team member is encouraged to propose ideas and improvements. Zakres obowiązków: Collaborate on both the back-end and front-end development of applications. Assist clients in transforming their existing applications to a new tech stack. Work in a remote-first environment with an expectation to join the team from our Gdańsk office 2 days per week. Contribute to the success of cutting-edge technology projects. Maintain a client-focused approach and engage in frequent client communication. Pay attention to detail and ensure the quality of development work. Oferujemy: Competitive Compensation: 25–30 EUR/h + paid days off (B2B) Alternative higher-rate option available without paid leave Remote-first culture with regular in-person collaboration. Presence in our Gdańsk office 2 days per week is expected. You’ll have real influence on technical decisions, architecture, and product development. Mentorship opportunities Self-development days Access to learning resources and tools We value sustainable work, mature communication, and work-life balance over overtime culture. Office Space in Gdańsk Our office offers: adjustable desks, bike parking, fully stocked kitchen. You’ll work with innovative companies from the fintech and climate-tech sectors across Scandinavia.