A profile · vol. 7
Eli Kaczmarek — staff engineer working on distributed systems and developer tooling. I care about how software holds up at 3 a.m., not how it demos.
I write about API design, incident postmortems, and the quiet craft of operating software in production. The good parts of this job rarely make a screenshot.
Selected work · 2020 — present
Listed in reverse chronological order. Hover any entry for the technical detail — stacks, links, and the one number worth remembering.
Tech lead · Cmd
A coordination primitive used by four internal teams. Replaces an in-house Redis-based shim that wedged twice a quarter.
Staff engineer · Stripe
Streaming pipeline reconciling ledger entries across 14 acquiring banks. Replaced a batch system that lost an hour every European morning.
Senior engineer · GitHub
Replaced the legacy lexical ranker with a hybrid scorer. Took a quarter; shipped behind a flag for two more.
Independent consultant · —
An honest tracing rollout. Took three months. Killed two of the company's four dashboards because nobody read them.
Maintainer · —
A small, well-tested rate limiter library. The good kind of project — narrow, finished, and used by people I respect.
In flight
First draft. ~3,000 words. The good half is about backpressure.
writing · April 2026
Re-reading. The first edition got me my last two jobs.
reading · ongoing
Timeline
Coordination team. Distributed locks, leases, and the rare service that benefits from being boring.
“Async at the edge.” Recording on YouTube, slides on the site.
Recognition for the reconciliation rewrite and three quarters of incident reviews.
Two thousand stars in the first month. Most of the issues were thoughtful.
Acquiring bank integrations team. The work I'm most proud of in this list.
After five years on search and code intelligence. Knew it was time before HR did.
Two engineers, one repo, four customers. The good kind of small.
Writing
Six months in production. The cost analysis nobody asked us to write.
StrangeLoop 2025 — slides, transcript, and the demo that didn't make the cut.
Postmortem. The proximate cause was a stale leader; the root cause was hubris.
Eighteen things to read before your first all-hands. Nine of them aren't about software.
Verbs over nouns. Predictable over clever. Why we keep getting this wrong.
A defense of the unglamorous parts of the job. The longest piece I've written.
Get in touch
Cold notes about distributed systems or developer tooling, requests to talk over something you're stuck on, or — best of all — links to things you've built. I'm bad at replying within the same day, but I do reply.