Senior ML Engineer, Search Optimization (Agentic Search)
- Level
- Senior
Not stated in the posting: salary, work type, visa.
Open. First seen 3 October 2026.
What this role asks for
Particular to this role
Neo4j
Rare in Nebius's other 292 open postings.
Standard for data science / ML roles
Python
Common in data science / ML postings at any company.
68% of this description is written for the role. The rest is Nebius's standard text, folded away below.
Read against Nebius's other open postings on this site.
The team: Agentic Search HIRES STEADILY
This role is one of 29 open in Agentic Search. 10 were posted in the last 30 days and the oldest in March: a team that hires all year rather than one being built.
WHAT THE TEAM WORKS WITH, ACROSS ITS POSTINGS
C++ (21 of 29), Golang (17 of 29), Python (13 of 29), Rust (11 of 29), LLM (9 of 29), Spark (8 of 29), Flink (7 of 29)
OTHER ROLES ON THIS TEAM
- Senior Software Engineer (Agentic Search) - Web Access Engineer posted Oct 16
- Senior Software Engineer (Agentic Search) - Web Access Engineer posted Oct 16
- Staff Software Engineer (Agentic Search) - Runtime posted Oct 16
- Staff Software Engineer (Agentic Search) - Runtime posted Oct 16
- Staff Software Engineer (Agentic Search) - Runtime posted Oct 16
- Staff Software Engineer (Agentic Search) - Crawler posted Oct 16
- Staff Software Engineer (Agentic Search) - Crawler posted Oct 16
- Staff Software Engineer (Agentic Search) - Crawler posted Oct 16
- Senior ML Engineer (Agentic Search) posted Oct 16
- Senior Product Analyst (Agentic Search) posted Oct 8
- Staff Software Engineer (Agentic Search) - Index posted Sep 16
- Staff / Senior Software Engineer (Agentic Search) - Crawler posted Sep 16
- Staff Applied AI Researcher (Agentic Search) posted Sep 16
- Senior Software Engineer (Agentic Search) – Web Rendering Engineer posted Sep 16
- Senior Software Engineer (Agentic Search) - Web Access Engineer posted Sep 16
- Staff / Senior Software Engineer (Agentic Search) - Runtime posted Sep 16
- Data Engineer (Agentic Search) posted Aug 25
- Senior Site Reliability Engineer (Agentic Search) posted Aug 10
- Staff Applied AI Researcher (Agentic Search) posted Aug 7
- Staff Applied AI Researcher (Agentic Search) posted Aug 7
- Senior Software Engineer (Agentic Search) - Web Access Engineer posted Jul 31
- Senior Software Engineer (Agentic Search) – Web Rendering Engineer posted Jul 31
- Senior SWE (Search) - Platform posted Jul 6
- Senior SRE (Search) posted Jun 23
- Staff / Senior Software Engineer (Agentic Search) - Crawler posted Jun 23
- Staff Applied AI Researcher (Agentic Search) posted Mar 30
- Staff / Senior Software Engineer (Agentic Search) - Runtime posted Mar 30
- Staff Software Engineer (Agentic Search) - Index posted Mar 30
From the team and dates on Nebius's own job board.
About the role
Nebius's standard text
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
As a Senior ML Engineer focused on Search Optimization, you will work on improving the quality of our search product across the all parts of the search stack.
You will work on problems such as query understanding, query reformulation and expansion, retrieval, ranking, reranking, and result selection. Your goal will be to identify where search quality is lost, develop better approaches, and turn them into measurable improvements in production.
This is an applied ML and information-retrieval role combining experimentation with production impact. You will work with real-world queries, large-scale search systems, and evaluation signals to improve relevance, recall, freshness, and overall result quality.
In this position, your responsibility will be to
Design, implement, and operate the retrieval system for a search vertical
Connect and tune the data pipeline, from ingestion to relevance tuning
Build knowledge-graph and entity-resolution layers: entity linking / NER, ontologies, and graph databases (Neo4j or similar)
Develop structured-extraction pipelines over messy, unstructured domain data
Reason about freshness and trust: model how confident we are in a fact and how stale it has become before we serve it
Define evaluation and quality metrics for relevance and drive measurable improvements
Collaborate with crawling, indexing, and ML teams to ensure retrieval and ranking requirements are met
Enable safe experimentation with retrieval, ranking, and extraction strategies
You may be a good fit if you have:
6+ years of software engineering experience, some of it in search / information retrieval
Strong IR fundamentals: inverted indexes, BM25/TF-IDF, query understanding, ranking, and evaluation (nDCG/MRR/recall@k)
Experience with vector & hybrid retrieval: ANN, dense+sparse fusion, embeddings models
Experience building structured extraction over messy/unstructured domain data
Fluent in Python and comfortable with systems-level performance work
Strong candidates may also have experience with:
Knowledge graphs: entity resolution, entity linking / NER, graph DBs (Neo4j), ontologies / schema design
Owning relevance / ranking for a real product and improving it against IR metrics
Data quality, truth discovery, or systems that decide how much to trust a piece of information
Published work on IR, ranking, or knowledge graphs
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
Nebius's standard text
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's standard text
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.
Nebius's standard text
If you need accommodations during the application process, please let us know.
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