Senior Software Engineer C# / .NET (m/w/d)

About this roleFor our client, a global leader in metrology and process control for semiconductor manufacturing, we are looking for a Senior Software Engineer C# / .NET (m/w/d) for a permanent position.The team is based in Mannheim and has more than 25 years of experience building high-precision measurement systems. Their software looks down to the atomic level and turns what it sees into actionable data for the production of the world’s most advanced computer chips.In this role you will design, build and maintain distributed software where performance, concurrency and reliability matter. You will also help shape how the team builds that software.At a glanceStart: ASAP or by agreementContract: Contract, full-time Setup: Hybrid, 3 days remote and 2 days on-site in MannheimWorking language: English (German is a plus)Your tasksDesign, develop, test and maintain scalable applications in C# and the .NET ecosystemWrite clean, well-documented code following Clean Architecture and the team’s coding standardsWork test-driven (TDD) and strengthen a culture of automated testingBuild robust multi-threaded solutions using locking, interlocking and parallelism in .NETTurn business requirements into technical solutions together with product owners, architects and cross-functional teamsReview code and give constructive feedback to keep quality and consistency highMentor junior and mid-level developers and provide technical guidanceIdentify and drive improvements in architecture, performance, reliability and maintainabilityTroubleshoot and resolve complex issues across a distributed software stackContribute to CI/CD and modern delivery practicesYour profileMust haveDeep, hands-on knowledge of C# 14 and modern .NETSeveral years of experience with multi-threaded programmingSeveral years of experience with high-volume in-memory data processingSolid experience designing and implementing RESTful APIsStrong command of OOP, SOLID, Clean Code, multi-layer architecture and TDDPractical experience with automated testing: unit tests, component tests, mockingGood working knowledge of UMLProven experience in hardware-related software developmentDegree in Computer Science, Software Engineering, Physics or a related fieldExcellent English; you work well in international, cross-functional teamsNice to haveReal-time systems, hardware integration or optical sensor data processing (strong plus)Legacy modernization, such as migrating a monolith to distributed, service-oriented systems or microservicesDistributed system design: event-based and object-based architecture, fault detection, causality methods, fault toleranceRelational database designFront-end development with .NET MAUIGerman language skillsWhat we offerA contract position at a global technology leader in a growing industryTechnically demanding work at the intersection of software, hardware and physicsA hybrid setup with 3 days remote per weekAn international team that values clean engineering and code qualityReal influence on architecture, and the chance to mentor other developersPersonal support from us throughout the hiring processInterested?Send us your CV with your salary expectations and notice period. Unsure whether you meet every requirement? Apply anyway. We’d rather talk to you than miss a good match.Find Jobs in Germany on Arbeitnow