Staff / Senior Software Engineer (Agentic Search) - Runtime

Nebius
Zurich, Switzerland / Netherlands / United Kingdom2026-09-16

About the job

We are looking for a Senior 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.

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

Qualifications

Minimum

Have 5+ 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

Preferred

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