Research Engineer, Index Intelligence

present of AI; Zürich; Hybrid; CHF 130,000 - 180,000; Full time

Job summary

Exa is an applied AI lab focused on building a search engine and API for AI models and agents. The role owns the signals and decisions that govern what gets crawled, indexed, refreshed, or dropped across a very large web corpus.

You will work on training and calibrating models for page quality, deduplication, and credibility at web scale, applying AI techniques to real retrieval problems. The work sits at the core of how AI systems find and consume information, enabling models and agents to rely

Job description

The role owns the signals and decisions that govern what gets crawled, indexed, refreshed, or dropped across a very large web corpus. A strong candidate brings hands on machine learning work with classifiers, rankers, and calibration, plus solid instincts for messy data at scale. The person must be able to define what a correct answer even means when no ground truth exists, and judge work by whether a decision changes and search improves.

How it fits the AI era

The work sits at the core of how AI systems find and consume information, since models and agents depend on a clean, well chosen index. Much of the judgment is still human: framing what quality and credibility mean, setting up supervision, and connecting a signal to real end to end impact. AI helps build and tune the models, but deciding which pages deserve to exist in the index stays a research and product call.

How it builds AI experience

The role offers direct practice in training and calibrating models for page quality, deduplication, and credibility at web scale, which is applied AI work on real retrieval problems. Building toward it means getting hands on experience with classification and ranking models, evaluation without clean labels, and data pipelines over large corpora. Familiarity with how search and retrieval systems use embeddings and vector indexes would help, given the company builds a search engine and API for AI models and agents.

Worth showing

• Classifier and ranker training
• Defining ground truth
• End to end impact thinking

This is our own read, written from the employer's posting and the company's Spotlight. The employer's posting is the source of truth for the role.

About Exa

Exa is an applied AI lab that builds a search engine and API for AI models and agents, per the company.