When a cover letter actually matters — and when it doesn't
At large tech companies with high application volume (Google, Meta, Amazon, Stripe), cover letters are rarely read at the screening stage. The ATS filters candidates by resume score and the recruiter works through the top results. By the time a human reads anything, the resume has already qualified you.
Cover letters matter more in these situations:
- Small and mid-size companies — where a founder or hiring manager personally reviews early applications
- Career transitions — frontend to backend, IC to EM, SWE to product engineering — where your resume alone doesn't tell the full story
- When the application explicitly asks for one — treat the ask as a screening signal; candidates who skip it get filtered
- When you have a referral — a cover letter that names the referrer and says something specific about the team is worth writing
For most large-company applications where you're a strong keyword match: skip it, or spend the 20 minutes improving your resume instead.
The structure that works
A good engineering cover letter is three short paragraphs and nothing else. Under 250 words. Written in plain, direct language — not "I am excited to express my interest in the opportunity to join your esteemed organization."
Paragraph 1: Why this specific role at this specific company
One or two sentences. Say something real. Not "your company is a leader in innovation." Mention a specific product, a specific engineering problem you know they're working on, or a specific reason the role fits your current trajectory. If you don't know enough to say something specific, skip the cover letter.
Paragraph 2: The one thing from your background most relevant to this role
Not a summary of your resume. Pick the single most relevant piece of experience and go one level deeper than your resume does. If the role is about high-scale systems and you built one, tell them a number the resume bullet doesn't have room for.
Paragraph 3: One sentence close
"I'd welcome the chance to talk about the role — happy to go deeper on anything in my background that's relevant." Done.
Examples by seniority
New grad / entry-level
I'm applying for the junior backend engineer role. I've followed Linear's approach to developer tooling since your team published the "Why we use Rust for our sync engine" post — the performance-first constraint maps directly to the kind of work I want to do.
My most relevant background: during my internship at Razorpay, I built the retry mechanism for failed payment events in Go, processing about 4M events daily. I built it to be idempotent from the start because the first version wasn't — and fixing that in prod taught me more about distributed systems than any coursework.
Happy to chat about that or anything else in my background.
Mid-level (3–6 years)
I'm interested in the staff engineer role on your data infrastructure team. I've been watching your Substack on the migration from Kafka to a homegrown log-structured system for the last 18 months — it's the same problem I'm in the middle of at my current company, at smaller scale.
At Mixpanel, I led the re-architecture of our ingestion pipeline from a monolithic Spark job to a Flink-based streaming system. We reduced end-to-end latency from 4 minutes to 18 seconds and cut infrastructure cost by 31%. I owned the design, the stakeholder alignment, and the 6-month migration with zero downtime.
I'd welcome a conversation if the background seems relevant.
The ATS check first
Before writing a word of a cover letter, check your ATS match score. A cover letter doesn't move your score — your resume does. If you're below 70% on the keyword match, spend the time on the resume first. Use Applyr's free ATS checker to see exactly what's missing. Then, if the role is one where a cover letter adds value, write it.