Senior Full Stack Developer (.NET, React)

Quick Facts

• Role: Senior Full Stack Developer (.NET, React)

• Domain: Financial systems

• Work model: Mostly remote; occasional office visits (minimum 1x in Warsaw/Katowice)

• Core technologies: .NET 6+, C#, React, TypeScript/JavaScript, GraphQL (Apollo Client, React Relay), microservices, micro frontends

Description

You’ll design and implement backend and frontend solutions for modern financial information systems. The project uses microservices architecture and GraphQL with .NET and React, including greenfield development and Micro Frontend (MFE) work. You will also implement asynchronous communication using RabbitMQ and MassTransit while maintaining code quality with unit tests and CI/CD.

Responsibilities

• Design technical architecture and develop microservices-based systems

• Build backend services in .NET 6+ / C# and frontend features in React, TypeScript, and JavaScript

• Design and implement GraphQL APIs using Apollo Client and React Relay

• Develop greenfield components and Micro Frontend (MFE) solutions

• Implement asynchronous messaging with RabbitMQ and MassTransit

• Work with relational and non-relational databases

• Create unit tests, improve CI/CD processes, and ensure code quality

• Participate in code reviews, document solutions, and make technical decisions

• Apply SOLID and Clean Code principles and software design patterns

• Collaborate with architects, analysts, testers, and business stakeholders

Requirements

• Minimum 7 years of commercial .NET development

• Minimum 5 years of experience building web applications with React, TypeScript, and JavaScript

• Minimum 2 years of experience designing and implementing GraphQL-based solutions

• Experience independently defining technical architecture and designing microservices architecture

• Experience implementing asynchronous communication with RabbitMQ and MassTransit

• Knowledge of Apollo Client and React Relay

• Experience designing UI/UX

• Experience with relational and non-relational databases, especially Microsoft SQL Server, Elasticsearch, MongoDB, CosmosDB

• Unit testing experience with xUnit, NUnit, and Jest

• Experience building and maintaining CI/CD processes, especially with GitLab

Benefits

• Medicover (including expanded dental coverage)

• FitProfit

• English language lessons

• F45 gym training at the office

• Internal referral program

• IT certificate funding

• Flexible employment forms: B2B, employment contract, or mandate agreement

• Work modes depending on the project: hybrid, remote, or onsite

• Events and integration trips

• Charity support initiatives (e.g., Szlachetna Paczka; #PomagamyNexio)