Senior .NET Developer – Enterprise Integrations
Location: Warsaw | Hybrid – 3 days per week from the client’s office
Contract: B2B
About the role
We are looking for an experienced Senior .NET Developer to join an international organisation operating in the transport and logistics industry.
You will work on a business-critical integration platform responsible for processing and consolidating shipment, status and customs-related data from multiple systems. The role combines backend development, system integration, production troubleshooting and gradual modernisation of an established .NET solution.
Your responsibilities
- Maintain and further develop an existing C# / .NET Framework solution based on Windows Services.
- Develop and optimise SQL Server / T-SQL, including stored procedures, query performance, transactions and deadlock analysis.
- Maintain data mappings and processing logic using AutoMapper, Dapper and XML/XSD.
- Develop and maintain integrations based on WCF/SOAP.
- Analyse and resolve production and data consistency issues.
- Cooperate with integration, business and master data teams.
- Support the platform’s modernisation towards modern .NET and REST-based integrations.
- Create and maintain unit and integration tests, technical documentation and development standards.
What we’re looking for
- 5+ years of commercial experience in .NET development.
- Strong knowledge of C# and .NET Framework 4.x.
- Experience with Windows Services and multithreaded processing.
- Very good knowledge of Microsoft SQL Server and T-SQL, including stored procedures, query optimisation, transactions and deadlocks.
- Hands-on experience with WCF/SOAP integrations.
- Experience with XML, XSD and XSLT.
- Familiarity with Dapper, AutoMapper and dependency injection.
- Experience with unit testing and mocking frameworks such as MSTest and Moq.
- Experience with Git.
- Strong analytical and troubleshooting skills.
- Good command of English.
Nice to have
- Experience in the logistics or transport industry.
- Experience migrating legacy .NET Framework applications to modern .NET (8+).
- Knowledge of REST APIs.
- Experience with Microsoft Azure, including Azure Functions or App Services.
- Knowledge of Docker and Kubernetes.
- Experience working in Agile/Scrum environments.
What we offer
- Opportunity to work on a business-critical integration platform used in a global logistics environment.
- Involvement in both maintaining the existing platform and its technical modernisation.
- Private medical care with LuxMed.
- MultiSport card.
Tech stack
C# | .NET Framework | SQL Server | T-SQL | WCF | SOAP | Dapper | AutoMapper | XML | XSD | XSLT | MSTest | Moq | Git
Nice to have: .NET 8+ | REST | Azure | Docker | Kubernetes