Senior Backend Engineer in London

Salary: Up to £145,000 base + equity

Location: Central London

Work Type: Hybrid, 3 to 4 days per week onsite

WeDo is partnering with a high growth AI startup building an agentic AI platform designed to solve complex, real world problems across global enterprise operations. The business is at an exciting stage of its journey. The foundations are in place, customers are using the technology, and the engineering team is now scaling both the platform and the systems behind it.

They're looking for a Senior Backend Engineer who wants to be close to the product, customers and technical decisions rather than owning a small component within a much larger organisation. You'll be joining a highly technical engineering team and working on problems across AI, distributed systems, enterprise data and performance engineering. This is a hands on role with genuine ownership. You'll help determine how the platform evolves as usage, customers and data volumes continue to grow.

Responsibilities:

• Design and build high performance backend services primarily in Python
• Build scalable distributed systems and APIs
• Develop pipelines capable of processing large volumes of complex enterprise data
• Integrate with external APIs and legacy enterprise systems
• Design asynchronous and event driven architectures
• Identify and solve performance bottlenecks across production systems
• Think critically about throughput, latency, computational cost and scalability
• Build resilient systems capable of handling failures and unreliable dependencies
• Define and monitor SLOs around performance, reliability and availability
• Work closely with engineers, founders and customers to turn complex problems into pragmatic technical solutions
• Own what you build from architecture through to deployment and production

Required Skills:

• 6+ years of software engineering experience
• Strong commercial Python experience
• Experience designing and operating distributed systems
• Experience with high throughput or data intensive applications
• Strong understanding of performance engineering and scalability
• Experience identifying and resolving real production bottlenecks
• Strong API and systems integration experience
• Experience with Docker and Kubernetes
• Experience within cloud environments
• Understanding of asynchronous processing and messaging architectures
• Strong knowledge of observability, monitoring and SLOs
• Experience owning systems from initial architecture through to production
• Strong communication skills and confidence making and defending architectural decisions

Experience building backend or platform infrastructure around AI, LLMs, Generative AI or agentic applications would be highly advantageous.

Why should I apply?

This is an opportunity to join an AI business at a stage where the engineering decisions you make can still genuinely shape the company and its technology. Rather than maintaining mature systems or working within one narrow part of a large platform, you'll have ownership of complex engineering problems and see the direct impact of what you build. You'll work across Python, distributed systems, large scale data, performance engineering and AI, solving problems where simply adding more infrastructure isn't always the answer. You'll also work closely with senior engineers, founders and customers as the platform scales, giving you exposure well beyond your immediate technical responsibilities. If you enjoy understanding why systems break, where bottlenecks occur and how to build software that performs reliably at scale, this is an opportunity to tackle those problems within a fast growing AI company.