p99.studio
SF ★ NYC ★ Berlin — engineering studio

Your app,
in weeks.

Mobile app development at AI speed — the latest coding agents and models under senior direction, from idea to the App Store in weeks, not quarters. The quality bar doesn't move.

Tell us the hard part See the work
chat4000 ★ Moovit ★ Veezo ★ your app next ★ chat4000 ★ Moovit ★ Veezo ★ your app next ★ chat4000 ★ Moovit ★ Veezo ★ your app next ★ chat4000 ★ Moovit ★ Veezo
Apps.
Shipped.

Mobile app development, end to end — native iOS & macOS in Swift/SwiftUI, designed, built and shipped to the store.

Start yours →
Our own product

chat4000

Native iOS/macOS client for self-hosted AI agents — push-to-talk, voice notes, tool calls.

Swift · SwiftUI · iOS · macOS
chat4000.com → hover a phone below ↓
chat4000 Moovit Veezo Moovit Veezo
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

Mobile app development

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

Swift · SwiftUI · React Native
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

Backend & distributed systems

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

Python · FastAPI · Postgres · AWS
04

Algorithms & performance

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

C++ · Rust · low-latency
05

Low-level & systems

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

C · C++ · Rust · WinAPI
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
How we're fast
01

Agents do the heavy lifting

Fleets of coding agents — the latest models — handle the long tail: scaffolding, tests, refactors, store metadata. They work around the clock and don't get bored.

02

Seniors direct and review

Every design call and every merged line lands under a senior engineer's judgment. AI widens the pipe — it doesn't hold the pen alone.

03

Tests gate every build

Suites and review gate each merge, so the App Store build is boring by the time it ships. Speed without a quality bar isn't speed.

More work
monday.comBackend engineering for monday.com's platform.Backend
Magic.devLarge-scale GitHub crawler for a frontier AI code-gen lab.Data
NustomDSPy few-shot optimization pipeline for code-gen performance.LLM
Real-time RF receiver controllers in C++ for military-grade comms.Embedded
dWalletZero-knowledge-proof research for WebAssembly in the wallet stack.Crypto
Airborne imaging systems in C++ across a multi-million-line codebase.C++
In-houseDistributed crypto trading system, #1 globally on execution speed.Low-latency
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
“
We handed over a hard routing problem and got back something that held up in production, on real traffic, on real devices.
MoovitMobile
“
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
“
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

p99.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 is “in weeks”?
A first working build is usually days, not months, and a shippable version lands in weeks rather than quarters. The exact number depends on scope — we tell you the real timeline on the first call, before any money moves.
Do you use AI to write our code?
Yes, deliberately. We run the latest coding agents and models on the long tail — scaffolding, tests, refactors, store metadata — and a senior engineer directs the work and reviews every merged line. Tests and review gate each merge, so the build that reaches the store is boring by the time it ships.
Can you take over an existing codebase?
That's most of what we do — inherited apps, half-finished projects, 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 at the end of any month.
Who owns the code?
You do — code, IP and accounts, from day one. Everything lives in your repo and your App Store / cloud accounts, so there is nothing to extract if you later take it in-house.
Do you only build mobile apps?
Mobile is where most projects start, but the studio covers AI/LLM systems, backend and distributed systems, algorithms and performance, and low-level work down to embedded and RF. 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 p99.studio SF · NYC · Berlin iMessage hello@p99.studio