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'm a Lead Engineer at Calvium, building Next.js and Nuxt systems for clients including Arts Council England and Rolls-Royce.

Outside work I build things for communities I'm part of: Dizzy.gg for fighting game rankings and tournaments, LLB Dojo for Lethal League Blaze practice, and Riichy for my local mahjong club.

A lot of my work is with people as well as code. I mentor engineers, interview for senior and lead roles, run study groups, and give talks. I also work directly with clients and stakeholders on requirements and delivery.

Work

The Dizzy.gg tournament list for Lethal League Blaze, showing 558 tournaments with dates, entrants, prizes and winners

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.

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 →

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

Building client systems in Next.js and Nuxt, along with 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.

Glencore · 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