Mid Full-Stack Developer

Quick Facts

• Role: Mid Full-Stack Developer

• Work model: 100% remote

• Project: International IT services project for a US-based client (long-term)

Description

You will develop and maintain backend services, responsive web features, and mobile capabilities for a fitness industry digital product. The role combines C#/.NET REST APIs and SQL Server work with React and React Native development in a distributed international team. You’ll also apply Clean Code/SOLID principles, write tests, participate in code reviews, and use AI-assisted tools to improve workflows.

Responsibilities

• Develop and maintain backend, web, and mobile solutions

• Build secure, scalable backend services and REST APIs with C#, .NET, ASP.NET Web API, Entity Framework Core, and SQL Server

• Implement responsive web and mobile features using React, React Native, TypeScript, JavaScript, HTML5, and CSS3

• Develop business logic and optimize SQL Server database structures

• Follow Clean Code, SOLID, and design patterns

• Write and maintain unit and integration tests

• Use AI-assisted development tools (GitHub Copilot, Claude Code, ChatGPT, or OpenAI API)

• Participate in technical discussions, code reviews, and task estimation

• Collaborate with a distributed international team

• Create and maintain technical documentation in Polish and English

Requirements

• 3+ years of commercial software development experience

• Strong experience with C# and .NET Core / .NET 8+

• Experience with ASP.NET Web API, Entity Framework Core, and SQL Server

• Practical experience with React and React Native

• Good knowledge of TypeScript, JavaScript, HTML5, and CSS3

• Knowledge of Clean Code, SOLID principles, and design patterns

• Experience with unit and integration testing

• Practical experience using AI-assisted development tools (GitHub Copilot, Claude Code, ChatGPT, or OpenAI API)

• Fluent Polish (mandatory)

• Minimum B2 English (written and spoken)

• Ability to work independently in a fully remote environment

• Strong communication and collaboration skills

Benefits

• 100% remote working model

• Full-time B2B cooperation agreement

• Work on an international project for a US-based client

• Opportunity to work with modern .NET, React, and React Native technologies

• Collaboration within a distributed international team

• Skill development in modern software engineering and AI-assisted development