EX-02 · Find the N where the ceiling stops moving

Difficulty: 🟡 · label difficulty: 2 Stuck? Ask in the clinic thread for EX-02 — one long-running thread per exercise, so the answers accumulate where the next person will look. Submit: post it in Show and Tell titled [solution · EX-02] ..., with your numbers and your interval.

Notebook 01 · ~45 min · Skill: sizing a first stage

Sweep n_candidates and find the point where Recall@N flattens. Then argue for an operating point using latency and cost, not just recall.

Acceptance criteria

• The sweep, plotted, with the chosen N marked
• The marginal recall per 100 additional candidates, as a table
• The latency cost of your choice from costs.latency_model
• One sentence a client would accept for why not simply N=1000

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