System Design AI
Design brief
Machine learningIntermediate45 min suggested

Ship a cheaper model without hiding regressions

Build a release decision from noisy evaluations, customer slices and production feedback.

Machine-learning engineers designing data, training and model systems.

Your approach: Explain the data, learning or model lifecycle in the brief. Support relevant quality and operating targets with evidence.

The problem

Design the evaluation and rollout system for replacing a support assistant model with a cheaper candidate. The candidate improves average benchmark scores but may fail disproportionately on rare, high-cost cases. Describe how the release decision is made and reversed.

  • The product handles 100,000 conversations/day. Human review capacity is 300 cases/day.
  • Existing ratings are sparse and skewed toward dissatisfied users; an LLM judge sometimes prefers verbose answers.
  • The candidate costs 35% less per call, but tool errors can trigger expensive manual escalations.

Work within these constraints

Human review budget

Declare the daily human-reviewed sample, including calibration and critical slices.

Required target: ≤ 300 cases/day

Evaluation integrity

Separate development examples from held-out release evidence; record model, prompt, tool and dataset versions.

Critical error gate

Overall average improvements cannot waive the defined critical-safety or incorrect-tool-action gate.

Release reversal

Identify the rollback signal, decision owner and how to attribute behavior to a version after rollback.

What to deliver

1

Metrics and slices

Define task-success, tool correctness, escalation cost and customer slices, including at least one rare critical case.

2

Judging and calibration

Describe human labels, judge disagreement, uncertainty and protection against style/verbosity bias.

3

Release experiment

Specify offline gates, traffic assignment, guardrails, sample limitations and go/no-go ownership.

4

Feedback and cost loop

Explain failure triage, dataset updates without holdout leakage, and total cost including escalations.