Stefan Annell

Technical Director at Mojang Studios

Stockholm, Sweden

steann87@outlook.com LinkedIn GitHub
About

Engineering leader
who ships great products.

I'm a software engineer turned technical leader with a mechatronics background and a passion for building strong engineering teams. After shipping Minecraft Dungeons and later working on its DLC and seasonal updates, I moved fully into technical leadership — focusing on clarity, collaboration, and scalable technical strategy in Unreal Engine.

I love helping teams grow, make smart decisions, and ship great products. Tech, people, and product — that's where I thrive.

10+
Years in software
6
Years at Mojang
3
Roles at Mojang
1
Research publication
Experience

Career timeline

Mojang Studios
6 years 3 months · Stockholm, Sweden
Technical Director
Current Aug 2024 — Present
  • Set the strategy and technical direction for Minecraft Dungeons II — defining how the team ships features in a fast, safe, predictable, and scalable way.
  • Partner with other discipline leads to align technical direction with the game's vision and requirements.
  • Own performance targets across every release platform.
  • Lead and support other leaders, providing the clarity and direction that keep the whole project aligned.
Tech Lead
May 2022 — Aug 2024 · 2 yrs 4 mos
  • Led the Tech & Online branch of Minecraft Dungeons II, owning its technical strategy end-to-end.
  • Designed the online architecture for dedicated servers and full cross-play.
  • Built the game's localisation pipeline.
Senior Software Engineer
Apr 2020 — May 2022 · 2 yrs 2 mos
  • Worked on Minecraft Dungeons in Unreal Engine — leading the design and implementation of cross-platform play, live-ops seasons, entitlements, and other online services.
Netlight
2 years 2 months · Stockholm, Sweden
Software Developer
Apr 2020 — May 2022
FIS
2 years · Stockholm, Sweden
Software Developer
May 2018 — Apr 2020
ÅF
1 year 10 months
Software Developer
Aug 2016 — May 2018
Hartvik Engineering
9 months · Uppsala
Embedded Software Developer
Jan 2015 — Sep 2015

Summer and part-time embedded systems programming.

Skills

Core competencies

Technical Leadership Unreal Engine C++ C Java Online Architecture Cross-platform Play Live-ops Dedicated Servers Engineering Strategy Team Leadership Mechatronics Performance Optimisation Localisation Pipelines Embedded Systems Game Development
Personal Projects

Building for fun.

SOURCE HUB OUTPUT TESSERA
Indie Game · Creator
Tessera

A browser-based factory-automation game where you place belts, machines, and hubs to route and transform shapes. Systems run continuously — the factory keeps working even when you're away. Engineered to stay smooth at scale.

TypeScript three.js WebGL2 AI
ecs-cpp template <typename... Cs> class Entity { // Cache-friendly component storage std::tuple<Cs...> components; template <typename C> C& get() { return std::get<C>(components); } };
Open Source · C++ Library
ecs-cpp

A header-only Entity Component System (ECS) for modern C++20. Components can be added to or removed from entities at runtime, with cache-friendly, arena-allocated storage for fast iteration. Built with templates and concepts to make misuse hard.

C++20 ECS Game Engine Open Source
OCTREE
Open Source · C++ Library
octree-cpp

A header-only octree / quadtree for modern C++20 that adapts to 2D or 3D at compile time from your own vector type. Stores any payload and answers fast spatial queries — spheres, boxes, and custom shapes composed with AND, OR, and NOT in a single pass.

C++20 Octree Header-only Open Source
verlet · collision
Open Source · Physics Sim
physim-cpp

A real-time 2D physics playground in C++20 — Verlet integration with circle and line collisions, friction, and restitution. Renders with SFML and ties together my own ecs-cpp and octree-cpp for cache-friendly entities and fast broad-phase collision queries.

C++20 Physics SFML Verlet
Research

Publication

Probabilistic Collision Estimation System for Autonomous Vehicles
Research paper · KTH Royal Institute of Technology · Mechatronics
Education

Academic background

KTH Royal Institute of Technology
Master's Degree — Mechatronics
2014 – 2016
KTH Royal Institute of Technology
Civilingenjörsexamen — Mechatronics
2013 – 2016
KTH Royal Institute of Technology
Bachelor's Degree — Mechanical Engineering
2010 – 2014