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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 have bet on Rust full-time and built everything in public: complete systems with specs, ADRs, test suites and CI — not tutorials.

Recent output: a framework-agnostic full-stack meta-framework (oxide), a reactive abstraction layer (quoin), an end-to-end HUNL poker AI (pkr-sota), and massive ongoing work on kod, glyim, and flux.

// this profile, as code
let shipped = vec!["flux", "kod", "vautr", "glyim", "stackbluff", "oxide", "quoin", "pkr-sota"];
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? -> elcoosp@gmail.com

Flagship Rust Work

Repository What it is Receipts
oxide Framework-agnostic full-stack meta-framework with a Rust core. React, Vue, Svelte, and Solid over one shared engine. Compiles to a single static binary, ships to 12 deploy targets. 18 crates · ODF binary wire format · 3-tier cache · 2,300+ commits in Oct 2026
quoin Framework-agnostic reactive abstraction layer for Rust. Write reactive business logic once using signals and effects, run across GPUI, Leptos, Dioxus, Xilem, or Floem. Unified Reactive API · Declarative macros · Tailwind class transpilation
kod Local-first AI coding-agent harness (TUI + CLI). Streaming agentic loop, multi-agent swarm, MCP & LSP clients, sandboxed shell, JSONL session audit. Your code never leaves your machine. 20 crates · ~4000 tests · Landlock / bwrap / sandbox-exec · 1,300+ commits in Oct 2026
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 · 580+ commits in Oct 2026
pkr-sota End-to-end heads-up No-Limit Hold'em poker AI in Rust. Precompute, train, export, and query a CFR blueprint on a single machine with nanosecond lookup times. Deterministic training · mmap blueprint loading · p50 ≈ 42ns queries · 460+ tests
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
flux Write-once UI language for native iOS & Android. Hot-reload on-device as binary IR patches over WebSocket — release builds compile to real SwiftUI & Jetpack Compose. 16 crates · ~63k LOC of Rust · 92 golden ISA vectors · 39 ADRs
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

TypeScript & Full-Stack Work

Repository What it is Receipts
takumi-motion Deterministic server-side animation engine that renders React components or HTML to GIF, WebP, or APNG. TypeScript/React integration · Server-side rendering pipeline · Created Oct 2026

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

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; oxide maintains strict spec-vs-code deviation docs.
  • 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; Miri-clean core crates in pkr-sota.
  • CI like it's production — clippy -D warnings, #![forbid(unsafe_code)] in every library crate, fuzzed wire protocol, mutation testing, parity harnesses, golden-hash CI gates.
  • 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 (October 2026)

  • oxide: Fixing website routing/CSS injection across render paths, refining the CLI/router scanner, and expanding documentation (local dev, CI, release, security) while enforcing workspace-wide build checks.
  • quoin: Implementing proper JoinHandle abort/detach semantics and fixing request_update recursion across all framework adapters (GPUI, Leptos, Dioxus, Xilem, Floem). Bounding cancellation waker registries to prevent memory leaks.
  • kod: Refactoring tools.rs by extracting shared helpers (atomic_write, kill_child_tree) to enable parallel tool splits. Closed v0.1.27 audit sweep with memory obfuscation fixes and documented the main-loop split proposal.
  • glyim: Fixing signed wrapping arithmetic and literal receiver method resolution. Investigating a critical LLVM backend miscompile where checked_* operations on signed integers incorrectly used unsigned intrinsics, requiring a coordinated fix across typeck, interp, and LLVM backends.
  • pkr-sota: Shipped K=7 action abstraction, but documented a +261 mbb regression in run 1 ("DO NOT SHIP"). Measured Phase 5 infeasibility at current resolution (time bottleneck) and corrected audit claims about memory size (UndoRecord is the dominant cost). Fixed parallel test temp-file races.
  • flux: Expanding ISA vector coverage for uncovered opcodes (remove_item_basic, clear_basic), fixing BOOL_EQ operand lengths, and ensuring content_address gracefully handles dangling child references without panicking.

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, reactive systems, or applied crypto — that is 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 · hyper · rustls · Oxc · Rolldown

Stats

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

Pinned Loading

  1. lynxpo lynxpo Public

    The missing Expo ecosystem for LynxJS. 66 genuine, non-stub native modules (Camera, SQLite, SecureStore...) written in Kotlin & Swift. Bridge the React-Native gap to Lynx today. 🚀📱

    TypeScript 3

  2. glyim glyim Public

    A research-grade compiler for a Rust-like language, written in Rust. Features NLL borrow checking, type inference, trait solving, and LLVM/bytecode backends — designed for readable code, not just p…

    Rust 1

  3. pkr-sota pkr-sota Public

    An end-to-end heads-up No-Limit Hold'em AI in Rust. Train a CFR blueprint offline, and query it anywhere in nanoseconds. 🦀 🃏

    Rust 1

  4. oxide oxide Public

    One Rust core. Every framework. A full-stack meta-framework with React, Vue, Svelte, and Solid adapters — compiles to a single static binary, deploys to 12 targets, with fast paths that skip JavaSc…

    Rust

  5. kod kod Public

    Local-first AI coding agent for the terminal, in Rust. Single binary — no Node, no Python, no Docker. Skills, multi-layer memory, tool calling, and swarm, pointed at Ollama, LM Studio, vLLM, or any…

    Rust

  6. 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