Chenyang Lai · 赖晨阳 — software engineer, AI applications & agent infrastructure

Real systems.
Public proof.

I design and ship complete products on my own — an AI document-review platform running in production, a coordination hub for coding agents — and contribute merged performance work to open source. Every claim on this page links to something you can read.

Case studies

Two products, built end to end by one engineer

Requirements, architecture, both ends of the stack, security, deployment, and the test suite that keeps it honest.

Tender Intelligence · AI document review In production

AI review for government tender documents

A review workspace for procurement and engineering tenders: it parses the document, reviews it clause by clause with dual-model cross-checking against a versioned law library, and produces a tracked-change revision — with a person approving every finding.

Long context
A real 105k-character sample showed a single full-context pass recalls only 24 of 42 findings. I redesigned the review as structure-aware chunked deep scans with a fact ledger, fixed coverage matrices, and deterministic merging — 75% more findings, every one anchored to source text.
Recall & cost
Rebuilt clause retrieval so exact legal clauses reach the context 24/24 (previously widespread misses); reordered prompts for KV-cache prefix reuse — cache misses down 43.8%, cost per review down ~20% with zero lost findings. Frozen eval: Recall@3 90%, 100% abstention on negatives.
Security
AES-256-GCM envelope encryption, SQLCipher at rest, non-exportable device keys, Cloudflare Access; blue-green Docker deploys on a VPS.
Quality
1,328 backend tests across 167 files, five CI workflows, fail-closed formatting gates on document output.
  • Python
  • FastAPI
  • React 19
  • TypeScript
  • SQLCipher
  • Docker
  1. 01 Upload and preserve originals
  2. 02 Parse and confirm metadata
  3. 03 Review against cited evidence
  4. 04 Accept, reject, or rewrite
  5. 05 Export a tracked revision
Automation drafts the findings. A person owns every decision.
AgentHub · CrossAgent protocol Private build

Local-first coordination for AI coding agents

A hub that lets heterogeneous coding agents work in the same repository without stepping on each other: shared tasks, write-intent conflicts, review bundles, and a replayable event stream — no model reasoning stored. I use it to run several agents in parallel on real projects, including this one.

Protocol
16 Streamable HTTP MCP tools: atomic task claims, structured TODOs, offline mailboxes, immutable review bundles, audit events.
Delivery
Three message paths — native push, hook fallback, mailbox — with sequence replay, dedupe, and explicit ACK lifecycles.
Evidence
Fixed benchmark at 100,000 events and 10,000 FTS messages: search p95 2.7 ms. 60+ unit and Playwright E2E cases across a pnpm monorepo.
  • TypeScript
  • Fastify
  • React 19
  • SQLite / FTS5
  • MCP
  • WebSocket
Agent A · bridge adapter
Agent B · channel adapter
AgentHub tasks · mailbox · review · audit
React dashboard · 9 control surfaces
Agents stay independent; the hub owns state, conflicts, and history.

Open source

Upstream, merged

Contributions judged by other maintainers' review bars, not my own.

cc-switch · 122,346★ Merged

A version-aware cache for Codex session usage

While using CC Switch I traced a slowdown to the same parent rollout file being re-parsed for every fork cutoff. I proposed a timeline cache keyed on file version, filed the issue with numbers, and landed the fix with the maintainer — including invalidation for appends, replacements, and nanosecond timestamp edges.

19.8× synthetic benchmark, 27.4 s → 1.4 s
−78.6% modeled JSONL parsing volume
2,252 existing tests passing on 3 platforms
Read PR #5626

Robotics

From simulation to a rover that runs

MSc Robotics team project at the University of Manchester — five engineers, one autonomous mobile manipulator.

Team 4 robot software architecture connecting perception, navigation, manipulation, and rover control modules
Team4-UoM-RSDP · 11 public repos Team of five

Autonomy and manipulation on real hardware

We built a ROS 2 system around a Leo Rover, a myCobot 280 Pi arm, an Intel NUC, a RealSense depth camera, and an RPLidar — from a Gazebo digital twin through to field runs.

  • Frontier-based exploration with Nav2, SLAM Toolbox, and EKF fusion for mapping unknown areas
  • YOLOv8 + HSV detection with depth back-projection and TF for 3D targeting; MoveIt 2 grasping
  • Verified against the requirements matrix: 125 g held over 5 s, about 2 h battery vs a 20 min target
  • ROS 2 Jazzy
  • Nav2
  • SLAM Toolbox
  • Gazebo
  • MoveIt 2
  • YOLOv8
Browse the team repositories

Toolkit

What I reach for

Grouped by the work, because that is how it gets used.

AI application engineering

LLM orchestration and evaluation, MCP, retrieval (FTS5/BM25), document parsing, PyTorch, computer vision

Product and full stack

TypeScript, Python, React 19, FastAPI, Fastify, Node.js, REST, WebSocket, SQL, Vite

Systems and performance

Rust, Go, C++, profiling, reproducible benchmarks, Linux, Docker Compose, Cloudflare

Quality and robotics

Pytest, Vitest, Playwright, GitHub Actions, accessibility; ROS 2, Nav2, SLAM Toolbox, Gazebo, MoveIt 2

Oil spill change detection preprocessing and reconstruction pipeline
Research · first author arXiv preprint

Oil-spill change detection from synthetic SAR

I reframed oil-spill monitoring as bi-temporal change detection, built a 879-pair Sentinel-1 dataset with a synthesis-and-restoration pipeline, and benchmarked eight models — best F1 90.67%, +17.4pp over the strongest segmentation baseline. The experimental discipline carried straight into how I test products.

Read the preprint

About

Chenyang Lai on a passenger ship

I like ambiguous problems that need careful evidence, explicit safety boundaries, and an interface people actually enjoy. Trained in computer science in two countries, now finishing an MSc in robotics.

  1. 2025 – 2026 exp. MSc Robotics — University of Manchester With Merit · Cognitive Robotics & CV, Software for Robotics
  2. 2023 – 2025 BSc Computer Science — University of Exeter Upper second-class honours · £5,000 academic excellence scholarship
  3. 2021 – 2025 BEng Computer Science & Technology — Guangdong University of Technology 2+2 joint programme · first-class university scholarship

Hiring for AI product or platform work?

Start with the code — everything above links to something you can read. Or just write to me.