Recommendation letter guide · Sample letter and email · Updated Nov 2026

Letter of recommendation for an AI Engineer

The short answer

The best AI engineer recommendation comes from someone who saw your system in production: your tech lead, engineering manager or the PM who owned the feature (for freshers and MS applicants, a project guide who supervised a real build). It should prove three things with specific stories: you measure quality with evals, you make sound trade-offs on latency and cost, and you own what you ship after launch.

See the sample letter Full AI Engineer interview guide

Who should write it

Pick the person who saw your work most closely, not the one with the biggest title.

Your tech lead or engineering manager

They can vouch for code quality, system design and how you handled production incidents.

The product manager who owned the AI feature

Shows you build for users and outcomes, not just for interesting models.

A professor or project guide (freshers and MS applicants)

Common for Indian students applying for an MS. Strongest when they supervised a project you actually built and evaluated.

What a AI Engineer letter must prove

Each quality needs a specific story. Here is the kind of line that proves it.

Measures quality

“Ananya built a 300-ticket eval set before we shipped, and it caught six regressions in the first year.”

Makes sound trade-offs

“She showed with evals that a smaller model handled short tickets just as well, cutting cost per draft by 45%.”

Builds for production

“She added a provider fallback and tracing before launch, so when our model provider had an outage, users barely noticed.”

Explains AI clearly

“Support leads trusted the copilot because she showed them exactly where it failed and what we changed.”

Structure: one page, five short parts

1OpeningWho you are, your role, how long and in what capacity you worked with the candidate, and the role or programme they are applying for.
2Headline claimOne sentence that sums up the candidate, e.g. “one of the most careful applied AI engineers I have worked with”. Only if true.
3Two specific storiesEach story: the problem, what the candidate built or decided, and the measured result (accuracy, latency, cost or adoption).
4How they work with othersOne short paragraph on code reviews, design notes and explaining model failures to non-engineers.
5CloseA clear recommendation and an offer to talk, with your contact details.

Sample letter of recommendation

From a tech lead, for a job application (fictional people and company)

I am Rohan Desai, Staff Engineer and tech lead for the AI team at Fabrikam Support Cloud (fictional). Ananya Reddy worked on my team for two years, building our support copilot, and I am glad to recommend her for an AI Engineer role.

Ananya is one of the most careful AI engineers I have worked with. Before we launched the copilot, she sat with our support leads and turned 300 real tickets into an evaluation set. Every prompt or model change has had to pass it since. In its first year it caught six regressions that would otherwise have reached our 300 support agents.

She also makes trade-offs with data. When model costs grew, she ran the eval set against a smaller model, showed it handled short tickets just as well, and routed them there. Cost per draft fell by 45%. Separately, she cut p95 latency from 7.2 seconds to 2.5 by streaming responses and running retrieval in parallel.

Ananya writes clear design notes, reviews code carefully and explains failures to non-engineers without jargon. Our support leads trust the copilot largely because she showed them where it was weak and what we were doing about it.

I recommend Ananya without reservation and would be happy to talk to you about her work.

Rohan Desai, Staff Engineer, Fabrikam Support Cloud (fictional) · rohan@example.com

All people, companies and numbers in this sample are fictional. Your recommender should write in their own words.

How to ask, and what to send

Make it easy to say yes: a short email plus a one-page brief.

Email to your recommender

Subject: Would you be a reference for an AI Engineer role?

Hi [Name], I am applying for AI Engineer roles, starting with [Company]. You saw my work on [project] more closely than anyone, so I would be grateful if you could write a short recommendation or take a reference call. To make it easy, I have attached a one-page brief: the role, three stories you might mention, and the numbers (eval results, latency and cost). Please change anything that does not match your memory. The deadline is [date]. If now is a bad time, no problem at all. Thank you, [Your name]

The brief to attach

The job description or programme, and why you want it (two lines).
Three stories they saw, each with the problem, what you built or decided, and the result.
The exact numbers: eval set size, accuracy before and after, latency, cost and users.
A one-line plain-English description of each system, so a non-specialist reader (such as an admissions committee) can follow.
The deadline, the format (letter, portal form or call) and where to send it.

Job, MBA, promotion or referral

Same stories, different emphasis.

Job application or reference call

Lead with one production system and its measured results. Many companies prefer a 15-minute call to a letter, so ask which they want; the same stories work.

MS or MBA application

Add potential: how the candidate learned, the depth of their technical work and how they compare with others the recommender has taught or managed. Follow the portal’s questions exactly.

Internal move or promotion (e.g. into the AI team or to senior AI engineer)

Show work already at the next level: owning an AI feature end to end, setting up evals others use, or leading a model migration.

Referral note to a recruiter

Three sentences: how you know them, the AI system they shipped and its best number, and why they fit this role.

Mistakes that weaken a recommendation

Listing technologies (“skilled in LangChain and vector databases”) instead of saying what the candidate built.
Accuracy claims with no context. Say what it was measured on.
A well-known professor or VP who barely knows your work. A specific letter from your project guide or tech lead beats a vague one.
Writing the letter yourself and asking them to sign it. Send a brief instead and let them use their own words.

Fix your resume next

Bullet bank, keywords from real job posts and a sample one-page AI Engineer resume.

AI Engineer resume (CV) guide

Keep going

AI Engineer resume (CV) guide AI Engineer interview questions with answers Practise out loud in a free AI mock interview

Frequently asked questions

Do AI engineer jobs need a letter of recommendation?

Most tech companies ask for reference calls rather than letters, usually near the offer stage. Letters matter most for MS and MBA applications, internal moves and some Indian and European employers. The same brief works for all of them.

Who should write my LOR for an MS in AI or computer science?

A professor or project guide who supervised real work, plus your manager or tech lead if you have work experience. Each letter should describe something you built, how you evaluated it and what you learned.

Can my product manager write the letter instead of an engineer?

Yes, especially for product-company roles. Pair it with a reference from an engineer if you can, so both your judgement and your technical depth are covered.

How long should a letter of recommendation be?

One page, four to five short paragraphs: introduction, two specific stories with results, how you work with others, and a clear close.