Senior Full-Stack Engineer: TypeScript, React & NestJS

Sigma Software; Województwo mazowieckie; On-site; PLN 180,000 - 300,000; Full time

Job summary

Sigma Software is seeking a Strong Middle / Senior Full Stack Developer to join a product-focused team building a large-scale AdTech platform. You will work across backend with NestJS and frontend with ReactJS, leveraging TypeScript and AWS to deliver enterprise-grade solutions.

The role emphasizes ownership, architecture input, and collaboration with architects, QA, and PMs on high-load campaigns and media workflows.

Qualifications

• 4-5+ years of commercial software development with JavaScript/TypeScript (backend focus)
• Strong backend experience with NestJS
• Solid frontend experience with ReactJS
• Hands-on experience with AWS cloud services
• Experience with enterprise/high-load applications
• Good communication and collaboration skills
• Upper-intermediate or higher English level

Responsibilities

• Design, develop, and maintain scalable Full Stack apps using JavaScript, TypeScript, NestJS, and React
• Implement complex business logic related to digital advertising campaign management
• Participate in architecture discussions, technical 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 following software engineering best practices
• Identify technical challenges proactively and drive solutions independently
• Contribute to continuous improvements in development processes and technical standards

Skills

JavaScript / TypeScript

Problem solving

Communication

Independent ownership

Teamwork

English proficiency

Tools

NestJS

ReactJS

AWS

Job description

Sigma Software is seeking a Strong Middle / Senior Full Stack Developer to join a product-focused team building a large-scale AdTech platform. You will work across backend with NestJS and frontend with ReactJS, leveraging TypeScript and AWS to deliver enterprise-grade solutions.

The role emphasizes ownership, architecture input, and collaboration with architects, QA, and PMs on high-load campaigns and media workflows.