hyhy.gg

Harry Hartley

Lead engineer, Bath/Bristol. I build and run production systems end to end.

About

I've been a software engineer for seven years, in consultancy, product and defence. I lead engineering at Calvium, building Next.js and Nuxt systems for clients including Arts Council England and Rolls-Royce.

Outside work I've built two production products by myself. Dizzy.gg is a rankings and tournament platform used by communities across three games. LLB Dojo is a training tool for a single game, and its daily puzzle ran unattended for more than 90 days. I designed, built and host both.

Before engineering I taught secondary computing. A lot of my work away from the code comes from that: running study groups and a graduate bootcamp, mentoring engineers, interviewing for senior and lead roles, and giving talks.

Work

Three products at different scales: a platform for any game, a deep tool for one game, and an app built in an afternoon.

The Dizzy.gg tournament list for the LLB Stadium community, showing 488 tournaments with dates, entrants, prizes and winners

The general platform

Dizzy.ggdizzy.gg

Rankings and tournament platform for multiple games. Glicko-2 ratings, live brackets and start.gg imports, on web and mobile.

games
3
games
communities
~10
communities
players ranked
5,590
players ranked
tournaments
796
tournaments
sets recorded
30,028
sets recorded

in its first three months, built and run by one person

Read the case study →

The sandbox mid-simulation, with characters placed, attack angles on, and trajectories drawn in SVG with arrows.

The deep single-game tool

LLB Dojodojo.hyhy.gg

Positioning trainer for Lethal League Blaze. Custom 2D physics engine, and a daily puzzle scored by expert consensus that rotated itself every week.

  • a daily puzzle that ran unattended for 90+ days
  • 2D physics engine written from scratch
  • scored against a consensus of expert players

Read the case study →

The afternoon build

Riichyriichy.hyhy.gg

The one-afternoon build →

Fairness-optimising table-draw manager for a local riichi mahjong club. Tested draw engine, seeded optimiser, no backend. Built in one afternoon.

Stack

  • TypeScript
  • React
  • Next.js
  • Node.js
  • Bun
  • Tailwind CSS
  • PostgreSQL
  • Prisma
  • React Native / Expo
  • Vue
  • Nuxt
  • oRPC
  • Zod
  • Vitest
  • Playwright
  • Docker
  • Kubernetes
  • AWS
  • Vercel
  • OpenTelemetry

Experience

2025 – now

CalviumLead Engineer

Leading engineering on client systems in Next.js and Nuxt, and building the internal templates and tooling the rest of the company builds on.

Arts Council England · Rolls-Royce

2023 – 25

AND DigitalSenior Software Engineer

Redesigned TravelChapter's whole system in TypeScript and Next.js and helped modernise how their engineers work. Added OpenTelemetry observability across microservices for the Office for National Statistics.

TravelChapter · Office for National Statistics

2022 – 23

Scott LogicSoftware Engineer

Led a small team working on Vuu, Scott Logic's open-source project, and worked directly with its stakeholder on requirements and delivery.

Vuu (open source)

2021 – 22

RocketmakersSenior Software Engineer

Built a home-automation platform for Sero Energy in React and Node on Docker and Kubernetes. Elected to the company's Web seat, looking after frontend practice across the business.

Sero Energy

2019 – 21

BMTSoftware Engineer

Built web applications for the Royal Navy and for internal use, from writing the backlog through to delivery. Ran the week-long bootcamp for new graduates.

Royal Navy

BSc Computer Science, University of Bath, with a placement year at Altran writing C, Ada and SPARK for high-reliability systems · PGCE Secondary Computing, UWE

Talks

  • Silent Design · SouthwestJS · 2024
  • Advanced TypeScript · internal engineering talk · 2025
  • Advanced React · internal engineering talk · 2025

Contact

Find me on GitHub