Models get data, never instructions.
Whatever a person or a web page says reaches the model as a claim with its source, so a stray instruction in an email cannot steer it.
Tochi Mba
AI engineer and full-stack developer
I'm Tochi, and I go by Rex. I'm an AI engineer at Jigsaw Create in London, where I designed and built Jigsaw Intelligence: a multi-agent system that lets people query and change complex business diagrams in plain language.
Outside work I run REX Technologies, my own product line: the LUCY assistant and its family of services, the weftai workflow runtime on npm and PyPI, and desktop and mobile apps like Flint and Android Headless Mirror. I graduated with a First in Computer Science with Cybersecurity from the University of Huddersfield.
psst — wake Lucy
- Based in
- United Kingdom
- Looking for
- AI engineering and full-stack roles
How I work
Small pieces, well tested, shipped.
I split a system into small services that each own one job, write down the decisions that matter, and keep the same checks in every repository so none of them drifts. I would rather ship something smaller that works than something bigger that almost does.
Safety comes before polish.
When a service can run code or hold a credential, its boundaries are built and tested first, and the interface after.
The same checks everywhere.
Lint, types and tests at full branch coverage in every repository, held by CI, so a change anywhere is held to the same bar.
Where I want to go deeper
- Agent orchestration
- Evaluating agents
- Prompt-injection defence
- Real-time media on desktop and TV
- Developer tooling
Build log
What I shipped lately.
last push · rexplayer ·
Read from GitHub every day: a square is a release, a tick a merged pull request, one row per project. Hover over one, or tap it, to see what it was.
The latest 6 releases and 34 merged pull requests, fetched 19 Oct.
Top projects
A closer look at my top projects.
8 of 45Products people install, services other services depend on, and a runtime published to npm and PyPI. Every one has a site, a changelog and a test gate.
LUCY
Python 3.12 · FastAPI · MCP · weftai · uv
An assistant hub with a family of small services behind it.
- Durable conversation runner with resumable event streaming
- Declarative plans: steps reference earlier results as $hits, not copied text
- MCP server and client in the same hub
- 9 services
- 431 commits
- last push 10 Oct
weftai
TypeScript · Zod · pnpm workspaces · Vitest · Python
Composable AI workflows: the model plans, your code executes, results never travel through the model.
- One tool call, three dependent lookups, zero identifiers copied by the model
- Operations defined once: name, description, Zod input schema, output type, handler
- Previews for the model, full sets for the code; positions index the full set
- @weftai/cli@0.6.0 · 1 Oct
- v0.6.0 on npm and PyPI
- 35 releases
- 1.5k npm downloads last month
Android Headless Mirror
C# · .NET · WPF · scrcpy · ADB
Your Android phone, in one window on your Windows PC, with its own screen off.
- Real touchpad gestures mapped to the phone: pinch, rotate, pan
- Blurred live background rendered on the graphics card at 60 fps
- Per-user installer, no admin rights, scrcpy bundled, auto-update
- v2.18.1 · 9 Oct
- 33 releases
- 282 commits
rexplayer
C# · .NET · WinUI 3 · Direct3D 11 · Media Foundation
Every file, stream and disc. A Windows media player built from scratch.
- Its own engine: format readers, media session, resampler and mixer
- Video decoded on the graphics card, straight into the window
- Gapless albums, cut to the sample
- v0.25.9 · 18 Oct
- 46 releases
- 941 commits
Flint
C# · Rust · Kotlin · DXGI · Media Foundation
Cast a PC screen to a Fire TV at the lowest latency the hardware allows.
- GPU capture, convert, downscale and hardware encode on Windows
- Fire TV receiver in Compose for TV: remote-operable, overscan-safe
- One wire protocol in Rust, C# and Kotlin, checked by golden vectors
- latest-mobile · 16 Sept
- 2 releases
- 182 commits
textwire
Python · Android · Kotlin · zstd · Twilio
Browse the web and search from a phone with no data connection, over plain SMS.
- Trained zstd dictionary and a framed wire format with golden vectors
- Retransmission of lost and reordered SMS frames
- make simulate runs the real server against a virtual phone, sends nothing
- 26 commits
- last push 14 Oct
Chika
Python 3.11 · Chrome Extension · Claude · OpenAI
An agentic assistant with full browser control, installed like a real app on Windows, macOS and Linux.
- Chrome extension: read tabs, navigate, click, screenshot, watch for changes
- Native installers for Windows, macOS, Debian and any Linux distro
- Auto-update gated on green CI; chika doctor verifies the install
- v2.0.0 · 6 May
- 99 commits
LinkPeek
TypeScript · Manifest V3 · Chromium · Playwright · GitHub Actions
See the media behind a link without leaving the page.
- Whole-thread Discourse media extraction with original/preview pairing and deduplication
- Adaptive link preparation driven by device tier and live page headroom
- One-handed browsing: gestures, mouse buttons, hover countdown and switch protection
- 150 commits
- last push 7 Oct
Day job · 2024 – present
AI Engineer at Jigsaw Create.
Architected and delivered Jigsaw Intelligence: a production multi-agent system on Azure that lets people query and change complex business diagrams in plain language.
- A worklist orchestrator that coordinates more than 30 tools within WebRTC packet-size limits
- A structured variable and template pipeline that keeps the model's context small
- Deterministic search tools that hand the model structured data to reason over
- A workflow engine with parallel, sequential and conditional steps, streaming results as they arrive
- Fixed a live WebRTC connectivity issue that was blocking the AI in a client's enterprise environment
- Delivered in seven months and shown as the Hero product at the British Legal Technology Forum
The LUCY system · 9 services
A closer look at LUCY.
LUCY is my assistant hub. Each service behind it owns one job and checks every caller against keyring, and what comes back to the model is data with its source, never instructions. Pick a member to see what it does, or pick one up and drag it.
hub · Python 3.12 · FastAPI · MCP
LUCY
An assistant hub with a family of small services behind it.
- you → LUCYa request becomes a plan of named steps
- LUCY → serviceseach step runs on the service that owns it
- services → LUCYresults come back as data, with where they came from
GitHub · last 12 months
Where the work went.
3,180 contributions on 42 days: 2,252 commits and 758 pull requests, the busiest day 385 on 10 Oct.
Last 13 weeks
Languages, by bytes of current code
- Python41%
- C#35%
- Kotlin9.5%
- TypeScript7.6%
- Rust3.0%
- JavaScript2.2%
- Other1.3%
Contact
Hiring for AI or full-stack? Let's talk.
Open to AI engineering and full-stack roles.Email is fastest; every public repository above is open for a look first.