Senior Software Engineer Enterprise Backend in London

Meet DeepL. DeepL is a global AI product and research company focused on building secure, intelligent solutions to complex business problems. Over 200,000 business customers and millions of individuals across 228 global markets trust DeepL's Language AI platform for human-like translation, improved writing and real-time voice translation. With a history of innovation, quality and security, DeepL is expanding beyond language into areas such as DeepL Agent – an autonomous AI assistant that transforms how businesses and knowledge workers get work done.

What Sets Us Apart: Our blend of cutting-edge AI technology, meaningful work and a culture where people genuinely thrive sets us apart. We are a team of innovators, researchers and creators driven by a shared purpose to unlock human potential by making work simpler, smarter and more connected. We value trust, curiosity and care at every level.

Join the Business Acceleration Track (BAT): The BAT team owns the "Financial Nervous System" of DeepL, architecting the platform that manages Identity, Access and Monetization for millions of users and global enterprises. This is hard tech – you’ll design distributed systems that handle high-frequency transactions, ensure data consistency across microservices and protect revenue streams from fraud. You’ll own the reliability and scalability of DeepL’s core business logic.

Your Responsibilities:

• Architect for consistency & scale: design backend systems for Identity (SSO/SCIM) and Billing, making high-stakes trade-offs between eventual consistency and strict ACID transactions in a distributed environment.
• Own data integrity: ensure ledgers are immutable, access controls are secure and systems are auditable, designing for failure so no transaction is ever lost.
• Decompose complexity: turn messy, ambiguous business requirements into clean, maintainable backend architecture.
• Drive technical excellence: mentor the team on best practices for C#/.NET Core, gRPC and event-driven architecture (Kafka), and set the standard for code reviews and system design.

Qualities We Look For:

• Distributed systems mindset: understand microservices, idempotency and distributed locking, and prevent race conditions in a billing system handling thousands of concurrent requests.
• Domain mastery or curiosity: experience or deep desire to master IAM (Identity Access Management), fraud prevention or fintech/billing architectures, recognizing these as engineering problems, not just admin tasks.
• High agency: proactively identify risks—whether security vulnerabilities or scaling bottlenecks—and fix them before they become incidents.
• Pragmatic architect: avoid over-engineering; choose reliable solutions (e.g., Postgres) over shiny new tools because stability is critical in a financial system.
• AI-native velocity: leverage AI-powered tools (GitHub Copilot, Claude) to accelerate velocity, eliminate repetitive toil, generate boilerplate code, test suites and debugging, focusing cognitive energy on high-value architectural decisions.

What We Offer:

• Diverse and internationally distributed team: more than 90 nationalities across the UK, Germany, the Netherlands, Poland, the US and Japan.
• Open communication and regular feedback: a culture of clear, honest communication and empathy.
• Hybrid work with flexible hours: two days in office per week and the flexibility to work from home, with trust in productivity.
• Virtual Shares: every employee receives Virtual Shares linking contribution to DeepL’s growth.
• Regular in-person team events: local gatherings, new-joiner onboardings and company-wide events.
• Monthly full-day hacking sessions: Hack Fridays allow you to pursue passion projects and collaborate across teams.
• 30 days of annual leave plus access to mental health resources.
• Competitive benefits: a globally tailored benefits package aligned with your location.

If this role and our mission resonate with you, but you don’t check all the boxes, don’t let that hold you back. At DeepL, it’s all about the value you bring and the growth we can foster together. Go ahead, apply and let’s discover your potential together. We can’t wait to meet you!

We Are an Equal Opportunity Employer: We welcome you to DeepL for who you are. We appreciate authenticity. Our product is for everyone, and so is our workplace. The more voices we have represented and amplified in our business, the more we all succeed. Bring us your experiences, perspectives and background. It’s in our diversity that we find the power to break down language barriers in the world.