Staff Software Engineer (Agentic Search) - Runtime

Nebius
London, United Kingdom
On-site

Who this role is best for

Strong fit for experienced systems engineers who design and operate high-throughput, low-latency services in AI infrastructure, with a focus on observability and cross-functional collaboration.

Best fit for

  • Experienced engineers with expertise in C++ or Rust and a track record of handling thousands of RPS in production systems
    — “strong hands-on expertise in C++ or Rust in real-world, high-load services”
  • Candidates who have operated their own code in production and debugged incidents effectively
    — “Have operated your own code in production: deployed it, debugged incidents, and rolled back changes when necessary”
  • Individuals who think end-to-end about request flows and optimize across multiple system layers
    — “Think end-to-end about request flows rather than staying within isolated components”
  • Professionals with systems-level performance understanding and optimization experience in CPU, memory, and data access
    — “Understand performance at a systems level — CPU, memory, networking, and data access”

Things to consider

  • The role demands a high degree of technical ownership and responsibility for production systems
    — “Build well-tested systems with clear responsibilities and interaction contracts”
  • Candidates must be prepared to work in a global, collaborative environment with ML and product teams
    — “Collaborate effectively across engineering, ML, and product teams”

How to stand out

  • Emphasize experience in optimizing performance-critical systems with measurable latency improvements
    — “optimising every layer from request handling to data access and response assembly”
  • Highlight your ability to decouple ML logic from core system internals during system design
    — “keeping ML logic decoupled from core system internals”
  • Showcase your background in building and operating large-scale APIs or high-load web applications
    — “High-load web applications or large-scale APIs”
  • Demonstrate your capability to define and implement observability primitives in production systems
    — “Define and implement observability primitives, including structured logs, metrics, traces, and latency breakdowns”
Pace · Fast PacedCollaboration · HighAutonomy · MediumDecision Impact · Team

Derived from job-description analysis by Serendipath's career intelligence engine.

What success looks like

  • design and operate core runtime services
  • build and optimize request flows
  • ensure reliability and observability
Typical background
8+ years of experience as a software engineerstrong hands-on expertise in C++ or Rust

Skills & requirements

Required

C++RustHigh-load ServicesPerformance OptimizationObservability

Preferred

Agentic SearchAI Infrastructure

Stack & domain

C++RustPythonBashCollaborationProblem-solvingCloud InfrastructureAISearch Engine

About the role

Original posting from Nebius

About Nebius:

Nebius is leading a new era in cloud infrastructure for the global AI economy. We are building a full-stack AI cloud platform that supports developers and enterprises from data and model training through to production deployment, without the cost and complexity of building large in-house AI/ML infrastructure.

Built by engineers, for engineers. From large-scale GPU orchestration to inference optimization, we own the hard problems across compute, storage, networking and applied AI.

Listed on Nasdaq (NBIS) and headquartered in Amsterdam, we have a global footprint with R&D hubs across Europe, the UK, North America and Israel. Our team of 1,500+ includes hundreds of engineers with deep expertise across hardware, software and AI R&D.

The Product

In a rapidly evolving world, trust in AI depends on AI agents being grounded in fresh, verified real-world data. Search is the foundation that makes this possible.

We are building an agent-native search platform designed specifically for AI systems rather than human users. Our product provides programmatic, low-latency, and observable search APIs that AI agents use to retrieve, filter, and reason over real-world information at scale.

The Role

We are looking for a Staff Software Engineer to work on the runtime systems of a novel search engine tailored for agentic AI consumption.

In this role, you will focus on building low-latency, high-throughput systems that serve search queries in real time. You will work on the critical path of user-facing requests, where performance, predictability, and efficiency directly impact product quality. You will design and operate systems that handle thousands of requests per second under strict latency budgets, optimising every layer from request handling to data access and response assembly.

In this position, your responsibility will be to

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

You may be a good fit if you:

Have 8+ years of experience as a software engineer working on production backend systems

Have strong hands-on expertise in C++ or Rust in real-world, high-load services

Have 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

Have operated your own code in production: deployed it, debugged incidents, and rolled back changes when necessary

Think end-to-end about request flows rather than staying within isolated components

Can balance correctness, latency, and development velocity, making pragmatic tradeoffs when scope or time requires

Collaborate effectively across engineering, ML, and product teams, communicating clearly in cross-functional settings

Strong candidates may also have experience with:

DBMS internals (open source or SaaS) and cloud infrastructure

High-load web applications or large-scale APIs

Performance-critical systems such as trading platforms or real-time data pipelines

Low-level performance tuning and hardware-level optimisation

Open-source contributions or active involvement in the engineering community

Competitive programming or CTF participation

SHAD or similar advanced technical programmes

Conference talks or technical publications

We conduct coding interviews as part of the process.

Benefits & Perks:

Competitive compensation

Career growth and learning opportunities

Flexibility and ownership

Collaborative and innovative culture

Opportunity to work on impactful AI projects

International environment and talented teams

What's it like to work at Nebius:

Fast moving - Bold thinking - Constant growth - Meaningful impact - Trust and real ownership - Opportunity to shape the future of AI 

Equal Opportunity Statement:

Nebius is an equal opportunity employer. We are committed to fostering an inclusive and diverse workplace and to providing equal employment opportunities in all aspects of employment. We do not discriminate on the basis of race, color, religion, sex (including pregnancy), national origin, ancestry, age, disability, genetic information, marital status, veteran status, sexual orientation, gender identity or expression, or any other characteristic protected by applicable law.

Applicants must be authorized to work in the country in which they apply and will be required to provide proof of employment eligibility as a condition of hire. 

If you need accommodations during the application process, please let us know.

Source: Nebius careers

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