AI cover letters

When the letter actually matters

What AI-generated letters reliably get wrong

• The opening. "I am writing to express my enthusiastic interest in the Software Engineer position at..." is the single most recognisable generated sentence in existence, and it wastes the only line that is guaranteed to be read.
• Praising the company in general terms. "Your commitment to innovation and excellence" could be addressed to any company, which tells the reader you did not look into this one.
• Restating the resume. The letter is attached to the resume. Repeating it in paragraphs is the most common structural mistake, and models do it by default.
• Length. Generated letters drift to four or five paragraphs. Nobody reads four paragraphs from an unknown applicant.
• Claims you cannot support. Same risk as the resume, with the same consequence in the interview.

What AI is actually good at here

• Research. Ask what a company's engineering blog covers, then verify it yourself and use one concrete detail. Specificity is the entire differentiator.
• Cutting. Write your own long version and ask for it in half the words. Models cut well.
• Finding the connection. Paste the job description and your background and ask where they genuinely overlap. Useful when the fit is real but not obvious.
• Catching the tells. Ask it to flag anything in your letter that sounds like a template. It recognises its own default phrasing.

Verify any factual claim it makes about a company before it goes in a letter. A confidently wrong detail about a product or a funding round is worse than no detail at all.

A structure worth using

Three short paragraphs, under 200 words in total:

• One: why this company specifically, with a concrete detail that proves you looked. One or two sentences.
• Two: the single most relevant thing you have built or done, and why it is relevant to the work they described. Not a list.
• Three: what you want to do there and a plain closing. No flourish.

Write that yourself and use AI to cut and check it. The ratio should be your substance, its editing - the same split that works for the resume.

Where CoPilot Interview fits

Disclosure: we build an interview assistant, so treat this as a disclosed pitch. The letter and the resume get you into the room; CoPilot Interview is for the room itself - a native Windows and macOS app that puts suggested answers on your own screen in about four seconds during live rounds, with a permanent free tier that needs no credit card.

Frequently asked questions

Do cover letters matter for software engineering jobs?

It depends entirely on where you are applying. At large company new grad portals they are rarely read. At startups where you apply directly, and for career changers whose resume needs explaining, they are often read by someone who matters - so concentrate your effort there rather than spreading it evenly.

Is it bad to use AI to write a cover letter?

Using it to author one usually produces a letter that reads as generated: a recognisable opening, generic praise for the company, and a restatement of your resume. Using it to research, cut your own draft in half and flag template-sounding phrasing is genuinely useful.

How long should a cover letter be?

Under 200 words, in three short paragraphs: why this company specifically with a concrete detail, the single most relevant thing you have built, and what you want to do there. Generated letters drift to four or five paragraphs, which nobody reads from an unknown applicant.

Can employers detect an AI-written cover letter?

Detection tools are unreliable, but readers often recognise the default phrasing without any tool, because the standard generated opening is extremely familiar. The practical fix is to write the substance yourself and use AI only to cut and check it.