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elcoosp/README.md

Louis Cospain

GitHub LinkedIn Email Location

Rust Output Contributions TypeScript

Rust engineer with a product-builder's track record. Eight years shipping TypeScript to production — six of them at Weenat (agri-tech, 10k+ IoT sensors, live on the App Store & Google Play). Since 2024 I've bet on Rust full-time and built everything in public: complete systems with specs, ADRs, test suites and CI — not tutorials.

Two years produced: a UI language that compiles to real SwiftUI & Jetpack Compose, a local-first AI agent harness, a zero-knowledge password manager, a from-scratch Rust-like compiler, and a sub-10ms multiplayer poker engine.

// this profile, as code
let shipped = vec!["flux", "kod", "vautr", "glyim", "stackbluff", "ataqu"];
debug_assert!(shipped.iter().all(|p| is_public(p) && is_spec_driven(p) && is_tested(p)));

let next = Role::rust().in_france(&["Nantes", "Paris", "remote"]);
// interested? → [email protected]

🦀 Flagship Rust work

What it is Receipts
flux Write-once UI language for native iOS & Android. Edit .flux source, hot-reload on-device in milliseconds as binary IR patches over WebSocket — release builds compile to real SwiftUI & Jetpack Compose. No webview, no JS bridge, no interpreter in prod. 16 crates · ~63k LOC of Rust · 92 golden ISA vectors · 39 ADRs · 19 CI workflows incl. wire-protocol fuzzing & mutation testing
kod Local-first AI coding-agent harness (TUI + CLI). Streaming agentic loop, multi-agent swarm, MCP & LSP clients, sandboxed shell, JSONL session audit with kod replay. Your code never leaves your machine. 20 crates · ~4000 tests · Landlock / bwrap / sandbox-exec
vautr Zero-knowledge password manager: OPAQUE authentication + Argon2id, offline-first sync. The server never sees your secrets. Rust core · React / Expo / GPUI clients · AGPL, self-hostable forever
glyim From-scratch compiler for a Rust-like systems language, written in Rust: lexing → HIR/MIR → type inference & trait solving → NLL borrow checking. full pipeline, no rustc internals
stackbluff Multiplayer poker platform: sub-10ms Rust engine, AI coach, bots, anti-cheat, clubs & tournaments, Stripe billing. built end-to-end by 5 parallel AI agents
ataqu 10 natively-integrated business apps (CRM, Chat, HR, Docs, SSO, Analytics…) on a single Rust + PostgreSQL core. monorepo · Next.js front-end

Also: chameleon — HUNL poker AI, mixture-of-archetype blueprints trained & benchmarked on an M1 (pure Rust) · skilldeck — local-first multi-agent AI orchestration (Tauri).

📦 Production track record (pre-Rust)

  • Weenat — agri-tech, 6 years full-stack TypeScript
    • 10k+ IoT weather sensors in production; mobile app live on App Store & Google Play
    • Led the React Native/JS → Expo/TypeScript migration across mobile & web
    • Built the IoT alert microservice (Node.js, AWS SQS)
    • Shipped a back-office letting marketing manage 5 languages with zero dev tickets
  • lynxpo — 66 Expo-style native modules (Camera, SQLite, SecureStore…) reimplemented for ByteDance Lynx with Kotlin + Swift twins, one pnpm workspace, live playground
  • vantage — multi-tenant merchant SaaS in Java 21 / Spring Boot 3.4: Saga/Outbox, event-driven, GraphQL, RabbitMQ

🧭 How I work

  • Spec before code — flux carries 39 MADR ADRs plus a full wire-protocol & VM-ISA spec; kod ships SPEC, ARCHITECTURE and TESTING documents.
  • Tests are the design review — cargo-nextest, proptest, insta snapshots, criterion performance budgets (parse < 5 ms, diff < 1 ms, VM eval < 2 ms); ~4000 tests across kod's crates.
  • CI like it's production — clippy -D warnings, #![forbid(unsafe_code)] in every library crate, fuzzed wire protocol, mutation testing, parity harnesses.
  • AI-augmented, engineer-owned — I ship daily with AI & MCP, and I built my own harness (kod) to keep the loop local, sandboxed and auditable.

⚡ Currently

  • flux: converging the iOS dev tier onto the declarative release pipeline (ADR-0048)
  • kod: work-stealing swarm dispatch and remote-daemon attach (see "Tracked gaps")

🎯 Open to

Rust engineer roles — backend, systems, product or security-adjacent. France (Nantes / Paris) or remote. I want a long-term product team where I own features end-to-end and keep shipping. Bonus points if the roadmap touches compilers, real-time, developer tooling or applied crypto — that's where my public work lives.

🛠️ Stack

Rust TypeScript React React Native Expo Next.js Node.js Spring Boot PostgreSQL Docker Kubernetes AWS

Rust ecosystem, in anger: tokio · axum · clap · ratatui · redb · blake3 · MessagePack · proptest · insta · criterion · cargo-nextest · OpenTelemetry

📈 Stats

Everything I build is public. If any of it is interesting to you — let's talk.

Pinned Loading

  1. lynxpo lynxpo Public

    66 Expo-style native modules (Camera, SQLite, SecureStore, and more) reimplemented for LynxJS with Kotlin + Swift twins — all in a single pnpm workspace with a live playground

    TypeScript 2

  2. skilldeck skilldeck Public

    Local-first AI orchestration layer that turns AI from a chat buddy into a coordinated engineering team — with branching conversations, multi-agent workflows (Sequential/Parallel/Evaluator-Optimizer…

    TypeScript

  3. ataqu ataqu Public

    The fast alternative to the SaaS stack lock-in. 10 natively integrated business apps (CRM, Chat, Automation, Docs, Scheduling, Forms, Inventory, HR, SSO, Analytics) on a single Rust + PostgreSQL ba…

    TypeScript

  4. stackbluff stackbluff Public

    Multiplayer poker platform with a sub-10ms Rust engine, AI coach, clubs & tournaments — built end-to-end by 5 parallel AI agents

    Rust

  5. vautr vautr Public

    The password manager that belongs to you. Constitutionally bound to AGPL, self-hostable forever, with a Rust core, OPAQUE authentication, and offline-first sync — built from a complete specificatio…

    Rust

  6. glyim glyim Public

    A modular, from‑scratch compiler for a Rust‑like systems language, written in Rust. Complete pipeline: lexing, parsing, name resolution, HIR/MIR, type inference & trait solving, NLL borrow checking…

    Rust