Research Engineer, Web-Scale ML & Search Signals

AItoolnavio; Zürich; Hybrid; CHF 110,000 - 170,000; Full time

Job summary

Exa is an applied AI lab building a groundbreaking search engine. We scale ML systems to crawl the web, train embedding models, and deploy fast vector databases.

We seek a research engineer to own the signals and the decisions behind ranking, defining what “right” means when ground truth is not available. You will collaborate across crawling, indexing and retrieval teams, and work on projects around page quality, credibility, and deduplication.

Qualifications

• You are comfortable owning a problem with no ground truth, where the first job is defining what the right answer means.
• Hands-on ML experience with classifiers, rankers and calibration, plus strong data instincts at web scale.
• You think in end-to-end impact. A signal only counts if a decision changes and search gets better.
• You like working across teams. Crawling, indexing and retrieval all consume what you build.
• You care about the problem of finding high quality knowledge and recognize how important this is for the world.

Responsibilities

• Make parsing work on the pages where it currently does not, and prove the improvement rather than assert it.
• Teach a model to judge page quality, and get everyone to agree on what quality means well enough to supervise it.
• Work on credibility and misinformation as a modelling problem: what a page claims, whether it is a reliable source of it, and whether it was written for a reader or for a crawler.
• Decide whether two documents are semantically the same or genuinely different, so we can deduplicate the web without collapsing pages that a user would want to see separately.

Skills

Ground truth definition

ML with classifiers

Rankers calibration

End-to-end impact mindset

Cross-team collaboration

Job description

Exa is an applied AI lab building a groundbreaking search engine. We scale ML systems to crawl the web, train embedding models, and deploy fast vector databases.

We seek a research engineer to own the signals and the decisions behind ranking, defining what “right” means when ground truth is not available. You will collaborate across crawling, indexing and retrieval teams, and work on projects around page quality, credibility, and deduplication.