Back-End Developer (.NET / C#)

Location: Poland (approx. 90% remote, occasional on-site visits in Warsaw)
Start Date: ASAP

About the Role

We are looking for experienced Back-End Developers to join a long-term software development project. You will be responsible for designing, developing, and maintaining backend applications, building APIs, optimizing databases, and ensuring high-quality software delivery within an Agile environment.

Responsibilities

• Design and develop software based on technical requirements
• Build and maintain REST APIs
• Design, develop, and optimize relational databases
• Debug, test, and improve application performance
• Create unit and integration tests
• Collaborate with cross-functional teams in an Agile/Scrum environment
• Report progress and contribute to technical documentation

Requirements

• Higher education degree
• Minimum 5 years of professional experience in IT projects
• At least 3 years of experience as a Back-End Developer within the last 5 years
• Strong knowledge of C# and .NET Core
• Experience developing web and desktop applications
• Practical experience designing and implementing REST APIs
• Good understanding of Clean Architecture and Domain-Driven Design (DDD)
• Strong knowledge of MS SQL and/or PostgreSQL
• Experience with SQL optimization, indexing, and stored procedures
• Hands-on experience with Entity Framework Core and Dapper
• Knowledge of authentication, authorization, and encryption mechanisms (JWT, OAuth2, FIDO2)
• Experience writing unit and integration tests
• Familiarity with Azure DevOps and Git
• Experience working in Agile/Scrum teams
• English at a level allowing you to work with technical documentation

What We Offer

• B2B contract via Experis
• Private healthcare (Medicover)
• Multisport card
• Group life insurance
• Flexible work model with approximately 90% remote work
• Long-term project with modern .NET technologies
• Opportunity to work in an experienced and collaborative development team