Middle FullStack Engineer (.NET, React.js)

Required for this role

Strong commercial experience with C# and modern .NET, with backend development as the primary area of expertise.

Solid knowledge of ASP.NET Core Web API and experience designing RESTful APIs, including authentication, authorization, validation, error handling, logging, pagination, filtering, sorting, and documentation.

Good knowledge of Entity Framework Core and experience working with relational databases, preferably MS SQL Server.

Strong understanding of OOP, SOLID, common design patterns, dependency injection, configuration, and asynchronous programming with async/await.

Experience with layered architecture, including Clean Architecture or Onion Architecture, and a clear understanding of dependency direction and code placement.

Commercial experience with React.js and TypeScript or JavaScript, including REST API integration, responsive interfaces, and reusable components.

Familiarity with TanStack Query and a client state-management library such as Zustand, Redux Toolkit, or an equivalent solution.

Experience with token-based authentication (OAuth 2.0 / OIDC / JWT) - Auth0, Entra ID or similar identity providers.

Experience with backend unit and integration testing, along with a basic understanding of frontend testing, debugging, application security, performance, and scalability.

Ability to work independently with an existing full-stack codebase, investigate technical issues, and communicate risks, blockers, and dependencies clearly.

Upper Intermediate English level or higher.

Nice to have

Experience with mobile and responsive application development.

Experience implementing and maintaining accessibility standards, including WCAG 2.2 Level AA.

Experience with Microsoft Azure, including App Service, Web App for Containers, Key Vault, Application Insights, Blob Storage, Azure SQL, and managed identities.

Experience with Azure DevOps, Docker, background jobs, messaging systems, and caching solutions such as Redis.

Experience working with microservices architectures.

Experience with UI component libraries such as Material UI, Ant Design, or equivalent.

Experience working with CI/CD pipelines is a plus.

Your responsibilities

Develop and maintain backend services and web applications using .NET, ASP.NET Core, React.js, and TypeScript.

Design and maintain RESTful APIs, business logic, authentication flows, validation, error handling, logging, and security across application layers.

Implement database schemas, queries, and data access using Entity Framework Core and MS SQL Server.

Build and maintain responsive frontend functionality, reusable components, state management, and API integrations.

Analyze the existing codebase, troubleshoot issues across the backend and frontend, and implement bug fixes and technical improvements.

Write and maintain unit and integration tests to support application quality and reliability.

Optimize backend services, database queries, and frontend components with performance and scalability in mind.

Collaborate with Business Analysts, QA Engineers, developers, and Project Managers, participate in code reviews, estimate tasks, and contribute to architectural and process improvements.

What you get

Your time off

18 paid vacation days and 10 paid sick days annually

10 Ukrainian public holidays

Maternity and paternity leaves

Marriage and Parenthood Package

Additional leave for major life events

Sabbatical leave opportunities

Learning & growth

Sombra University workshops and internal learning programs

Tech Communities and knowledge sharing sessions

Language courses and workshops

Mentorship opportunities

Health & well-being

Sports compensation or health insurance coverage

Participation in races and marathons

Corporate doctor (telemedicine)

Well-being initiatives and workshops

And even more

Company-provided technical equipment

PE administration and tax support

Internal referral program

IT Club loyalty program

Company events and volunteering initiatives

Before you apply

Our recruitment team will carefully review your profile, and if we see a good match with the role, we'll reach out to you shortly.

If you don't hear from us within 5 business days, it means we've decided to continue the process with other candidates for this position. Thanks for understanding.