p99.studio — mobile app development & engineering studio · SF · NYC

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Apps.
Shipped.

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

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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 ↓

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 →

Mobile app development

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

Swift · SwiftUI · React Native

AI & LLM systems

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

DSPy · agents · RAG · evals

Backend & distributed systems

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

Python · FastAPI · Postgres · AWS

Algorithms & performance

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

C++ · Rust · low-latency

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

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.

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.

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

NNustomDSPy 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

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.

Contact

Tell us the
hard part.

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

Let's do a 5-min call →