Senior Backend Engineer – Low-Latency AI Search

Nebius; Greater London; On-site; GBP 110,000 - 160,000; Full time

Benefits offered by this job

Competitive compensation

Career growth

Flexibility and ownership

Collaborative and innovative culture

Impactful AI projects

International environment

Job summary

Nebius is seeking a Senior Software Engineer to work on the runtime systems of a novel search engine tailored for agentic AI consumption. You will build low-latency, high-throughput services that handle real-time search queries, shaping performance across the critical path from request handling to data access.

You will contribute to architecture, observe system behavior, and partner with ML teams to improve ranking components while maintaining strong reliability and observability in production

Qualifications

• 5+ years of experience working on production backend systems.
• Strong hands-on expertise in C++ or Rust in real-world, high-load services.
• Built and operated high-load, low-latency user-facing systems handling thousands of RPS under strict latency constraints.
• Understand performance at a systems level - CPU, memory, networking, and data access.
• Collaborate effectively across engineering, ML, and product teams, communicating clearly in cross-functional settings.

Responsibilities

• Design, implement, and operate core runtime services for serving search queries at scale.
• Build and optimise request flows, including query processing, retrieval orchestration, and response assembly under strict latency budgets.
• Develop systems that maintain performance and predictability under high load.
• Optimise CPU, memory, and data access patterns in performance-critical paths.
• Ensure reliability, observability, and predictability across production services.
• Build well-tested systems with clear responsibilities and interaction contracts, while remaining flexible as architecture evolves.
• Define and implement observability primitives, including structured logs, metrics, traces, and latency breakdowns.
• Monitor throughput, latency, and resource usage, and drive improvements in performance and cost efficiency.
• Collaborate with indexing and ML teams to integrate retrieval and ranking components, keeping ML logic decoupled from core system internals.
• Support experimentation and iteration through controlled rollouts and rigorous benchmarking.

Skills

5+ years backend experience

C++ or Rust

Low-latency systems

Cross-functional collaboration

Tools

C++

Rust

Job description

Nebius is seeking a Senior Software Engineer to work on the runtime systems of a novel search engine tailored for agentic AI consumption. You will build low-latency, high-throughput services that handle real-time search queries, shaping performance across the critical path from request handling to data access.

You will contribute to architecture, observe system behavior, and partner with ML teams to improve ranking components while maintaining strong reliability and observability in production