Secondary-school teacher who builds and ships software — full-stack web apps, local AI tools, and classroom apps. I care most about the parts that are easy to skip: tests on the maths, accessibility, and writing down why a decision was made.

Portfolio, on one page: tokkathedj.github.io

Amigo · code private · write-up A local-only AI assistant for my house: nothing leaves the building. Language models run on a desktop GPU (Ollama), speech goes in and out locally (faster-whisper, Piper), and one chat page works hands-free from a phone. Around it are a microcontroller on the desk (button, buzzer, LED strip, motion sensor), a Raspberry Pi front door that wakes the desktop when it's needed and covers for it with a small model, a smartwatch face, smart lights, and games for my kids. The server is plain Python with no framework. Amigo keeps a dated engineering log of what broke and why, and a self-check that catches the server freezing and restarts it. A status page on the Pi says what needs a person (a missed morning step, an overdue backup, a broken new app) and nothing leaves the house. A "ship it" list runs each deploy step from my phone, then checks the live result.

Canopy HR · live demo A complete HR platform: people records, hiring pipeline, onboarding, time off, timesheets, simulated payroll and benefits, performance reviews, anonymous eNPS surveys, reporting. Next.js 16, TypeScript, Prisma + PostgreSQL, Auth.js. Effective-dated job history, a ledger for time-off balances, one approval engine for every request type, role checks enforced on the server. CI on every push; light and dark themes, with zero axe-core violations on every page, for every role, in both.

Paper Edit Edit long-form video and podcasts by editing the transcript. Runs entirely on your own machine — no cloud, no subscription, no account. Python, FastAPI, Whisper, FFmpeg; pytest suite. Exporting a real 97-cut edit went from about 30 minutes to 4 once each cut decoded only its own span — checked frame by frame against the old output (same frame count, every frame ≥ 49 dB PSNR).

Games Arcade · play 75 party, carnival and kids' games in one searchable catalog, no install. Every new app is played each night by a test that waits, presses Start and plays on a phone and a tablet screen; one that passes, and that a person has played, goes live in one tap (why). Its Math Worksheets grade by mathematical value, not exact text — 2(x+3) is accepted for 2x+6 — using a small polynomial-equivalence checker with no libraries.

Math Tools · live Interactive manipulatives for students: algebra tiles, balance scale, fractions, number line, place value, probability. React, Vite, TypeScript, Tailwind. The balance scale solves for x on either side, with fractions and negatives — and has the tests to prove it.

VR Math Rooms · open on a Quest Three WebXR rooms for teaching in a Meta Quest headset: plot points and read off slope and the line's equation, stand on y = mx + b and feel the hill change as m does, and sort a month's expenses into 50 / 30 / 20 — which balances at $3,200 and $4,500 but never at $2,400, where even the cheapest needs take 66% of take-home pay: the rule assumes slack. A-Frame, one HTML file per room, no build step; walking blinks instead of gliding, to spare stomachs. Checked by script on a real GPU: clicking (3, −9) plots (3, −9), above the floor.

Also: a phone app for a roadside-assistance business that shows which call channel actually pays per hour worked, including drive time and dead runs (client work, private).

The check that deleted everything — a pre-commit safety check that ran inside the repository it guarded and recorded 1,794 files as deleted, how it was caught before merge, why the first fix lasted two days, and fixing it where it enters.

Every page said 200 OK — auditing my own kids' apps: two copies that drifted, six apps installing with a blank icon, a quiz that taught a rule backwards, three dead tiles, and a risk I overstated, each with the check that now catches it.

Shipping on a teacher's schedule — how a one-page list, a Y/N runner and a weekly health check got a backlog of fixes across nine projects live in one evening, and the twelve things that broke on the way.

Believe the photograph — three bugs from Amigo that passed every test I had, what finally caught each one, and the thing my sons found in one round.

The client is a kid — redesigning Amigo's face in one evening: five versions tuned to my own taste, then one sentence from my son that pointed at the reference I'd ignored, and what that changes about designing for students.

Three ways a working system stops working — a week of keeping Amigo's server up: crashes that were deploys, two safety nets switching each other off, and an answer lost to a connection that died two seconds after a wake.

Tests that play the game — three checks said a game was fine; playing it for fifteen seconds said otherwise. A nightly test that plays every new app, the one-in-ten it first missed, and a cat voice that never made a sound.