mainloop.studio
SF ★ NYC ★ Berlin — engineering studio

Small team.
Big output.

Backend development by senior engineers, multiplied by the latest AI agents and models. You pay for judgment — the volume comes with it.

Tell us the hard part See the work
JUDGMENT ★ × AGENTS ★ = SHIPPED ★ JUDGMENT ★ × AGENTS ★ = SHIPPED ★ JUDGMENT ★ × AGENTS ★ = SHIPPED ★ JUDGMENT ★ × AGENTS ★ = SHIPPED
One senior.
Many hands.

The staffing model — without the bodyshop.

Start yours →

A SENIOR ENGINEER

Owns the problem, the architecture and the review bar. One name accountable.

AN AGENT FLEET

The latest coding agents and models — drafts, tests, migrations and refactors, around the clock.

A SHIPPED BACKEND

Production in weeks, quality gated by suites and review.

Services
⚡

Need someone right now?

Production is down. The deadline is Friday. The contractor ghosted. We jump in same-day, get to root cause, and ship the fix.

Not just firefighting — a long-term project can start right away too.

Get help now →
01

Backend development

APIs, data pipelines, event systems, storage — distributed systems designed for load and failure, owned from schema to deploy.

Python · FastAPI · Postgres · AWS
02

AI & LLM systems

Agent loops, RAG, prompt pipelines, evals — AI workflows that replace real manual work, measured before they ship.

DSPy · agents · RAG · evals
03

Algorithms & performance

Profiling, latency budgets, algorithmic design. We took a distributed trading system to #1 globally on speed.

C++ · Rust · low-latency
04

Low-level & systems

Win32/WinAPI internals, embedded down to 4 KB of RAM, real-time RF, hardware wallets.

C · C++ · Rust · WinAPI
05

Mobile app development

Native iOS & macOS in Swift/SwiftUI — or React Native when it fits. Shipped to the store.

Swift · SwiftUI · React Native
Numbers
20+YEARS OF C/C++ IN PRODUCTION
#1GLOBAL EXECUTION SPEED FOR ITS STRATEGY
½THE WORLD'S BUSES TRACKED BY OUR ALGORITHMS
4KBSMALLEST PRODUCTION RAM TARGET
What stays human
H
Architecture & tradeoffsThe calls that shape the next five years don't get delegated to a model.
H
Code review — every lineAI-written or not, a senior reads it before it merges.
H
Saying noTo scope creep, to shortcuts, to shiny tech that doesn't serve you.
H
The pagerWhen something breaks, a human who knows the system answers.
More work
monday.comBackend engineering for monday.com's platform.Backend
Magic.devLarge-scale GitHub crawler for a frontier AI code-gen lab.Data
In-houseDistributed crypto trading system, #1 globally on execution speed.Low-latency
NustomDSPy few-shot optimization pipeline for code-gen performance.LLM
dWalletZero-knowledge-proof research for WebAssembly in the wallet stack.Crypto
Real-time RF receiver controllers in C++ for military-grade comms.Embedded
Airborne imaging systems in C++ across a multi-million-line codebase.C++
What clients say
“
They took the parts of the platform nobody wanted to touch and made them boring again. Handed back code our own team could read.
monday.comEngineering lead
“
Scoped it on a call, shipped a working crawler, then kept it running while we changed our minds twice. No account manager in the middle.
Magic.devInfrastructure
“
They actually measured the model pipeline before and after instead of telling us it felt better. That's rare.
NustomFounding team
“
We handed over a hard routing problem and got back something that held up in production, on real traffic, at real scale.
MoovitPlatform
“
Deep cryptography work delivered with the write-up we needed to defend it internally. Senior from the first message.
dWalletProtocol
“
Real-time C++ against unforgiving hardware, delivered to spec. They asked the questions our other vendors didn't.
Elbit SystemsComms R&D
Studio

mainloop.studio is a senior engineering studio out of San Francisco, New York & Berlin, founded by an ex-Unit 8200 engineer. No account managers, no juniors, no handoffs.

FAQ
How fast can you actually move?
Faster than a team this size has any right to be — agents carry the volume, seniors carry the judgment. In practice that's a first working slice in days and a shippable version in weeks rather than quarters. You get the real timeline on the first call.
Do you use AI to write our code?
Yes, deliberately — and we're specific about where the line sits. Agents handle the volume: scaffolding, tests, refactors, migrations, glue. A senior reads every merged line, AI-written or not, and tests gate each merge.
Can you take over an existing codebase?
That's most of what we do — inherited services, half-finished migrations, systems whose original authors are gone. We start by reading it and telling you honestly what's salvageable and what isn't.
What if something is on fire right now?
We jump in same-day, get to the root cause, and ship the fix — production down, a Friday deadline, a contractor who ghosted. Use the “Need someone right now?” card at the top of Services and mark it urgent.
How do you charge?
Per project or per month, agreed up front — no hourly surprises and no change-request theater. Small, well-defined work is a fixed price; ongoing work is a monthly rate you can stop any time — no risk.
Who owns the code?
You do — code, IP and accounts, from day one. Everything lives in your repo and your cloud accounts, so there is nothing to extract if you later take it in-house.
Do you only do backend?
Backend and distributed systems are where most projects start, but the studio also covers AI/LLM systems, algorithms and performance, low-level and embedded work, and native mobile. See Services.
Where are you, and what about time zones?
San Francisco, New York and Berlin — so US and European hours are both covered by someone awake. Founded by an ex-Unit 8200 engineer.
How do we start?
Send one message describing the hard part. You get a same-day answer and a 5-minute call — no discovery-call maze, no forms to fill in twice. Tell us the hard part →
Contact

Tell us the
hard part.

One email. No discovery-call maze. Same-day answer.

Let's do a 5-min call →
© 2026 mainloop.studio SF · NYC · Berlin iMessage hello@mainloop.studio