rosneri
~30 audiobooks a year, still time to write

Neriya Rosner

Backend-oriented full-stack engineer · Senior @ DoorLoop · Tel Aviv

I build payments infrastructure at DoorLoop — fund flows and Stripe Treasury, where mistakes are expensive and hard to reverse. I write about what breaks and why: queues, idempotency, and systems that fail loudly instead of silently.

~/rosneri — zsh
$ whoami
neri — payments infra. ships TypeScript, reads everything else.
$ ls ~/writing --recent
14kMardead-letter-queue.md8.2kFebdeterministic-guardrails.md7.1kJanidempotency-keys.md
$ cat now.txt
43 public repos · strict TypeScript · 1 failed startup · 0 silent failures
$
$ ls ~/writing --sort=recent

Field notes

What I learned the hard way, written down so I don't have to learn it twice.

all posts
Featured · engineering

Deterministic guardrails for AI-written code

A new approach: as an agent writes more of the code, careful review stops scaling. So I encode each standard — strict types, architectural seams, structure caps — as a mechanical check the model can't talk past — enforced at every layer, from the agent's own AI hooks down to CI.

Neri Rosner·Mar 2026·13 min read
“A style guide is advice. A guardrail is a check that returns a non-zero exit code — the model can't talk past it.”
From the post
$ whoami --depth

Owning the hard parts

I'm happiest a few layers below the surface. I don't learn an advanced topic just well enough to use it — I go deep enough to own it: design the architecture, set the conventions the rest of the team builds on, and carry it all the way to production. Hand me the gnarly, high-stakes part of the system — the money path, the failure modes, the thing nobody wants to touch — and that's the part I actually want.

It's less a skill than a temperament: read the source, build the mental model, write down what I learned, and turn the scary unknown into something the team can reason about and trust.

Distributed systemsPayments infrastructureEvent-driven architectureDomain-driven designType-level TypeScriptIdempotency & consistencyObservabilityAI agent tooling

When things fail, I'm reliable

Production breaks; what matters is what happens next. That's where I'm at my most useful.

  • Failure-mode-first. I design for what happens when a message can't process or a deploy goes bad — before the happy path.
  • Recoverable by design. Idempotency, dead-letter queues, replay/redrive, and audit trails so an incident becomes a Tuesday, not an outage.
  • On-call ownership. I carry the pager for what I build, and I'd rather be paged than have it fail silently.
  • Calm under pressure. Methodical triage, honest comms, and fixing the cause — not just the symptom.
  • Findable. Structured logs and tracing so “what's stuck, since when, and why” is answerable in seconds.
$ whoami --verbose

About

Neri RosnerChubby, the unofficial mascot
Tel Aviv, Israel
Senior FS Engineer @ DoorLoop
HE native · EN pro · FR learning

I'm Neri. Backend-leaning full-stack, currently on payments infrastructure at DoorLoop — fund flows, Stripe and Treasury, the event-driven core that moves customer money. I design for the failure case first: the happy path mostly takes care of itself, so I spend my time on what happens when a message can't process, a deploy goes bad, or a schema drifts under a parked event.

That shows up as a few non-negotiables — strict types (any is a compile error, not a preference), small files, idempotency as a design input, and systems that fail loudly instead of silently. CQRS and the outbox pattern on the inside; an analytics store I query ad-hoc so "what's stuck, since when, and why" is a question I answer in seconds.

Ex-technical-founder: SpecBite, a software-requirements SaaS. My failed startup — I learned more from it than from most things that worked. Before that, a full-stack app licensed to the Israeli courts and police, and a logistics tour in the paratrooper brigade that taught me more about systems than any framework has. On the side I build dev tools like @neriros/ralphy, and I read constantly.

Inside my work at DoorLoop
43
public repos
~30/yr
audiobooks
7+
years shipping
any
is a compile error
The stack I live in
TypeScriptNodeReactPostgreSQLStripeTreasuryCQRSKubernetesAWSRedisPostHogAstro
$ cat ~/now-listening

The listening log

~30 a year, mostly while the tests run. A backend engineer's idea of a personality.

~30books
a year, give or take a sprint. Split: systems, startups, sci-fi, and an embarrassing amount of LitRPG.
Now playing
Tress of the Emerald Sea
Brandon Sanderson · 1.6× speed, obviously
Recently finished2025 → 2026
Designing Data-Intensive Applications
Martin Kleppmann
systems
The Pragmatic Programmer
Hunt & Thomas
craft
Project Hail Mary
Andy Weir
sci-fi
Dungeon Crawler Carl
Matt Dinniman
litrpg
Thinking in Systems
Donella Meadows
systems
The Mom Test
Rob Fitzpatrick
startups
$ git log --grep="neri" --oneline

What people say

”

Neriya is a champion! Wholehearted service — even when I needed him at 1am, he was there for me.

Geva CohenGeva
”

A professional in everything related to full-stack and front-end development. A hard worker, committed, sharp-minded and quick to learn. I highly recommend him.

Yossi ZoorCEO, eType
”

Neriya demonstrated an understanding of proper software engineering, alongside creative thinking and problem solving. I'm happy to recommend him.

Gilad SharoniCOO, Puzzle Projects
”

Thank you, Neri, for developing and designing our appointment-scheduling website. Our expectations were met and beyond — we're delighted with the results!

Nov BiranCEO, Cleaf
”

I had special plugin requirements for a WordPress site; Neriya understood them and delivered to my complete satisfaction, at a very reasonable price. My next job goes straight to him.

Yoav KlugerFounder, Sinesim
”

More than six months working together across a variety of projects. The site is beautifully designed, secure, fast and pleasant to use. Highly recommend!

Gil OmidiOwner, Sadeflowers
”

Neriya developed and designed a complicated organizational system for us. Communication was good, and the work was fast and efficient. Highly recommend.

Ram-el BinyminCEO, Cargo
”

Excellent service — working with Neriya was excellent. Highly recommended, thank you!

Matan MendelsonClient
”

Neri, you're a professional senior with high work ethic. I'm happy to work with you!

Idan ChenColleague
”

A professional at crazy levels! He guided and accompanied me through building my website and marketing automation. Absolutely recommend!

Gil SternClient
$ ./contact.sh

Let's talk.

Not job-hunting — but always up for trading notes with like-minded people: payments and systems folks, dev-tool tinkerers, fellow obsessive readers. If the problem is fun and the types are strict, I'm in. I read everything; I reply to most of it.