Joël van der Werf

Joël van der Werfヨエル・ファン・デル・ウェルフ

Software engineer and game programmer in Tokyo. Seven years building and shipping Unity games at Gamebasics (Miniclip), and the author of Hydro, my own Vulkan game engine and editor.

  • 7+ years professional game development
  • C#, Unity, C++, Vulkan
  • Japanese JLPT N4, studying for N3

Now Building an unannounced game in a major franchise at Miniclip. In Hydro, splitting the editor from game projects. Studying for JLPT N3. Open to C# / .NET, Unity and engine roles in Tokyo.

See my projects Read my CV
Eonlore: Miko walks up the stone path to a forest shrine at night, lanterns glowing and fireflies in the air
Eonlore, my tactical turn-based RPG, running in my own engine, Hydro. See the game · Read about the engine

What I work on

Games played by millions

Unity client work on live football management games: Football Head Coach, Ultimate Football Manager and Online Soccer Manager, plus unannounced titles, the shared frameworks they're built on, and the CI/CD pipelines that build and ship them.

Engines and graphics

A C++17 / Vulkan engine with its own editor, ECS, asset pipeline, native scripting, 2D and 3D renderers, and Box2D and Jolt physics, and Eonlore, a tactical RPG built on it. A master's in Game and Media Technology behind it.

AI-assisted development

Harnesses that let coding agents work safely on large codebases: project instructions, skills, convention linters, validation scripts and CI, for both Claude and local models. Grounded in training neural networks at university and in my own projects.

Selected work

All projects, ranked

Football Head Coach 27 app icon
Work · Gamebasics / Miniclip

Football Head Coach and Ultimate Football Manager

Feature development and maintenance on live, licensed sports management games, and the shared frameworks and AI harness behind them.
Eonlore: a lantern-lit merchant street with villagers
Personal · Game on my own engine

Eonlore, a tactical RPG built with Hydro

 Diagram: an agent reads its instructions and must pass lint, validation and CI
Work and personal

AI workflows and agent harnesses

From the devlog

All posts

  1. Games in their own repositories: separating Hydro from its first game

    Hydro, its editor and its first game all lived in one repository. The plan to give every game its own repo, the 16 couplings in the way, and the first five steps.

    • Hydro
    • Architecture
    • Tooling

  2. Making an engine readable to AI agents

    Hydro has 500+ source files and strict house rules. Here is the harness that lets Claude and a local Qwen model work in it without guessing.

    • AI
    • Tooling
    • Hydro

  3. Rules, views and a game session: structuring game code

    How the diorama RPG keeps its battle maths testable without a GPU, its UI dumb, and its run state alive across scene changes.

    • Hydro
    • Architecture
    • Gameplay

Experience

Over seven years as a professional software engineer in games, after more than ten years of building things on my own.

  1. Apr 2025 – now

    Software Engineer

    Deel K.K., Tokyo · Miniclip / Tencent titles and support
    • Feature development and maintenance on Football Head Coach and Ultimate Football Manager
    • Developing an unannounced game in a major franchise, and the shared frameworks used across the studio's games
    • Building the AI harness the team uses to work with coding agents
    • Setting up and maintaining CI/CD for all of the studio's games with Jenkins and TeamCity
  2. 2019 – 2025

    Unity Developer / Software Engineer

    Miniclip (Gamebasics), Netherlands
    • Front-end engineer on games built and run by the studio, in multidisciplinary teams
    • Unity client programmer on Football Head Coach, an NFLPA-licensed American football manager
    • Full-stack on Dynasty Duels, a multiplayer real-time strategy game: networking, back-end and Unity client
    • Native Android app for Online Soccer Manager
  3. 2017 – 2018

    HoloLens Unity Developer (intern)

    Delta-N, Netherlands

    Mixed reality interactions for Microsoft HoloLens.

  4. 2020 – 2023

    MSc Game and Media Technology

    Utrecht University

    Game physics, advanced graphics, computer animation, computer vision, AI for games and crowd simulation. Thesis on procedurally generated levels that train player skill.

  5. 2015 – 2019

    BSc Software Engineering

    The Hague University of Applied Sciences

    C#, UML, algorithms, SQL and databases, and security.

Skills

Daily work

  • C# and .NET
  • Unity
  • Git, CI/CD: Jenkins, TeamCity, GitHub Actions
  • Client architecture, DI, MVP

Engine and graphics

  • C++17
  • Vulkan, OpenGL
  • GLSL, HLSL
  • EnTT, Box2D, Jolt, ImGui

AI and tooling

  • Neural network training and machine learning
  • AI for games, computer vision
  • Claude Code, skills, local models (Qwen, Ollama)
  • Python tooling, agent-safe CI

Also

  • Unreal Engine 5, GAS
  • Unity Gaming Services, Photon
  • ASP.NET Core, SQL
  • JavaScript, React
Nederlands
Dutch
Native
English
English
Full professional
日本語
Japanese
JLPT N4, studying for N3. Living in Tokyo.

Building a game, an engine, or the tools around them?

I'm based in Tokyo and open to conversations about Unity, C++ and engine roles, C# and .NET software roles, and teams that want to put AI agents to work on real codebases.

Send me a message LinkedIn GitHub