Senior C# DeveloperLocation: London (Fully Onsite) Employment Type: Permanent Salary: 50,000 - 60,000 (DOE) Visa Sponsorship: Not availableWe''re working with a London-based organisation that is looking to hire an experienced Senior C# Developer to join their engineering team in a fully onsite position. This role is ideal for someone who enjoys hands-on development, working closely with the business, and taking ownership of complex systems.The RoleAs a Senior C# Developer, you''ll be responsible for designing, developing, and maintaining business-critical applications built on C#/.NET and SQL. You''ll play a key role in technical decision-making, improving code quality, and ensuring the reliability and performance of core systems.You''ll work closely with other developers, QA, product owners, and non-technical stakeholders, contributing across the full software development lifecycle.Key ResponsibilitiesDesign, develop, and maintain applications using C# / .NETWrite, optimise, and maintain SQL queries, stored procedures, and database schemasContribute to technical architecture and system design discussionsCarry out code reviews and promote best development practicesSupport and mentor junior and mid-level developersTroubleshoot, debug, and improve existing systemsCollaborate closely with business and technical teams onsiteEssential Skills and ExperienceStrong commercial experience as a Senior C# DeveloperAdvanced knowledge of C# / .NETStrong experience working with SQL (SQL Ser