Strong Middle / Senior Full Stack Developer (TypeScript / React)
Sigma Software3 hours ago
Warsaw, PolandMid Level / Senior
Responsibilities
- Design, develop, and maintain scalable full-stack applications using JavaScript, TypeScript, NestJS, and React.
- Implement and support complex business logic for digital advertising campaign management.
- Participate in technical discussions, architecture decisions, and solution design activities.
- Collaborate with developers, architects, QA engineers, and project managers.
- Improve application performance, scalability, reliability, and maintainability.
- Develop clean, maintainable, and well-tested code.
- Identify technical challenges proactively and drive solutions independently.
- Contribute to development process improvements and technical standards.
- Build and support enterprise-level advertising workflows, integrations, and media processing capabilities.
Requirements
- 4–5+ years of commercial software development experience with JavaScript and TypeScript, primarily focused on backend development.
- Strong backend development experience with NestJS.
- Strong frontend development experience with React.
- Hands-on experience with AWS cloud services.
- Understanding of scalable system architecture and software engineering best practices.
- Experience with enterprise-level or high-load applications.
- Strong problem-solving, analytical, communication, and collaboration skills.
- Ability to work independently and take ownership of technical solutions.
- Upper-Intermediate or higher English level.
- Familiarity with AI-powered development tools such as Claude and Codex is a plus.
- Experience with Jenkins, Terraform, and complex or enterprise platforms is a plus.
Tech Stack
Categories
About Sigma Software
Sigma Software is a London-headquartered, privately held IT consultancy that designs and builds custom software for startups and enterprises. The company provides end-to-end services—engineering, web and mobile development, .NET/Java platforms, AR/VR, and UI/UX—delivered via outsourcing, managed teams, and consulting. Founded in 2002, it supports long-term product development and modernization projects across multiple industries for global clients.