Quick answer: feed AI the job description, target stack, two shipped examples, and one tradeoff you handled. Then ask for a short letter that proves fit without inventing impact.
Start from the engineering problem
Ask AI to identify whether the role needs product delivery, platform reliability, API work, data pipelines, frontend quality, or incident response. The letter should answer that need first.
Use shipped evidence, not tool lists
Pick one or two shipped examples: a service you launched, a performance fix, a migration, an internal tool, or a production bug you resolved. Mention stack only when it supports the proof.
Control the generator output
Require a concise draft, then ask AI to mark unsupported claims, inflated seniority, and sentences that only repeat the resume.
Prompt
Act as a strict software engineering cover letter editor. Based on this JD, target stack, my shipped examples, and one technical tradeoff I handled, draft a concise cover letter. Do not invent metrics, team size, architecture ownership, or production impact.