Senior Software Engineer API Enterprise Full-Stack

Salary: £60,000 - 100,000 per year

Requirements:

• We look for an enterprise-first mindset, with a focus on enterprise IT and security admins as primary users.
• We need deep expertise designing scalable backend systems, RESTful APIs, and distributed architectures, primarily in C# / .NET.
• We expect experience with high-scale distributed systems in production.
• We value strong API design fundamentals and system design skills.
• We look for hands-on experience with modern enterprise API building blocks such as MCP, CLIs, and OAuth.
• We want a track record of leading projects across multiple teams and managing cross-team contracts and dependencies.
• We need ownership of services end-to-end, including production operations, incident response, and on-call.
• We value comprehensive testing, learning from incidents, and a focus on mature SLOs and reliability.
• We look for AI-native velocity, with experience using AI-powered tools to accelerate delivery.
• Bonus points for zero-downtime migrations on live systems.
• Bonus points for experience with metering, quota, or usage-data systems.
• Bonus points for experience in a compliance environment such as SOC 2, ISO 27001, or C5.

Responsibilities:

• Drive enterprise API adoption by owning features that turn enterprise interest into durable adoption.
• Build governance and compliance capabilities such as roles and permissions, projects, data residency, and auditability.
• Own services end-to-end, including participation in the API on-call rotation.
• Improve public API reliability toward four nines by implementing strong contract testing, monitoring, and SLOs.
• Prevent breaking changes and security vulnerabilities before they reach enterprise customers.
• Work across DeepLs technical and organizational structures to navigate dependencies and ship cohesive enterprise capabilities.
• Contribute across the stack and ship features that create delightful, frictionless experiences for external developers and internal engineering teams.
• Own product decisions and implementation with an enterprise-first focus.

Technologies:

• AI
• API
• Backend
• C#
• MCP
• OAuth
• Security
• ASP.NET
• Claude Code
• Copilot
• Frontend
• GitHub
• Network
• RBAC
• React
• TypeScript
• Fullstack

More:

We are DeepL, a global AI product and research company building secure, intelligent solutions for complex business problems. Our Language AI platform is trusted by over 200,000 business customers and millions of individuals across 228 global markets for translation, improved writing, and real-time voice translation. Founded in 2017, we are now around 1,000 employees and are backed by Benchmark, IVP, and Index Ventures. You will join our API Enterprise team in London, working in a hybrid setup with two office days per week, flexible hours, virtual shares, regular in-person team events, monthly Hack Fridays, and 30 days of annual leave. We are a diverse, internationally distributed team with colleagues in more than 90 nationalities and locations including the UK, Germany, the Netherlands, Poland, the US, and Japan. We value open communication, regular feedback, and a culture built on trust, curiosity, care, innovation, growth, and well-being.

last updated 36 week of 2026