
Unity Technologies2020–2026
CI and test automation for the Unity Engine organisation
Six years on the CI and test systems behind the Unity engine. I moved the Graphics SRP codebase (500 developers, 30,000 commits) into the engine repository with no data lost and no development stop, and test coverage grew 50 times.
- 500 developers on the migrated codebase
- 30,000 commits migrated
- ×50 test coverage
- 20+ platforms tested
- 0 data lost, no development stop
Context
Unity’s Engine organisation builds the Unity runtime and editor. Its graphics tests run on more than 20 platforms: desktop, mobile, XR and consoles, some of them under NDA. I joined as a Software Development Engineer in Test and stayed six years.
Problem
The Graphics SRP code and its tests lived outside the engine monorepo, and updates landed in phases instead of continuously. Integration problems surfaced late. At the same time, the test suite had to keep its coverage on every platform while many teams pushed changes every day.
What I did
- Migrated the Graphics SRP codebase and its test suite into the engine monorepo: 500 developers, 30,000 commits. No data was lost and development did not stop. Updates went from phases to continuous integration and delivery.
- Maintained the graphics test systems (.NET, Python, Bash) across more than 20 platforms.
- Made test runs faster with test selection (targeted triggering) and reuse of results across revisions, while keeping coverage.
- Onboarded teams on version control (Git, Mercurial), CI and testing.
- Built and supported monitoring and reporting with Grafana and BigQuery.
- Mentored junior engineers on the team.
Results
- Test coverage grew 50 times after the migration.
- Graphics updates moved from phased releases to continuous integration and delivery.
- Zero data loss and no development stop during the migration of 30,000 commits used by 500 developers.
- The graphics test suite covers more than 20 platforms that Unity supports, including platforms under NDA.
- Test runs got faster with targeted triggering and reuse across revisions, with no loss of coverage.
Recommendations
I managed Théo for over five of the six years he spent at Unity Technologies, and in that time I watched him grow from a strong individual contributor into one of the most capable and trusted engineers on the team. He has a rare ability to combine strategic thinking with consistent, high-volume delivery — he doesn't just identify what needs to be done, he follows through and gets it done, thoroughly and reliably.
Théo built tools and systems that became essential to teams well beyond his own, and he maintained them with genuine care for the people who depended on them. When he proposed a technical direction that turned out not to be the right one, he was the first to acknowledge it and pivot to a better approach. That kind of intellectual honesty, paired with his willingness to take full ownership of complex problems, made him someone other teams actively sought out for guidance.
He is also a natural knowledge sharer. Whether through announcements, documentation, presentations, or simply being available to help a colleague think through a problem, Théo consistently invested in making the people around him more effective. He mentored junior engineers with patience and trust, and he communicated with a directness that people appreciated.
Any team or organization that gets to work with Théo will find someone who takes ownership, delivers with quality, communicates clearly, and genuinely cares about leaving things in a better state than he found them. I recommend him wholeheartedly.
Jan Borup JakobsenSenior Manager, Automation and Tooling at Unity. I've had the pleasure of working with Theo for several years at Unity and he's one of the most skilled engineers I have ever worked with. He's had large impact on Unity's graphics related CI pipelines and tooling, enabling this important area of the Unity Engine to cover all the relevant dimensions of build configurations at scale. Theo has great work discipline and builds solid solutions, embracing command line tools and automation. Theo is also easy to work with and we've had numerous code review sessions iterating together to find the best solutions. He's also been an early adopter for AI agentic development, improving his productivity even further. I'm thankful for his time at Unity and he's leaving a legacy behind that is robust and easy to maintain. He'll be missed!
Henrik KjellanderStaff Software Engineer, Release & Engineering Services at Unity I had the pleasure of working with Theo, and I can confidently recommend him.
As our Build and Release Engineer, Theo was an essential part of the team's success. He has a deep understanding of CI/CD and build systems, but what really sets him apart is his ability to make complex processes easy to understand. He was always happy to explain, guide, and help us improve not only our build pipelines but also the overall quality of our code and products.
What I appreciated most about Theo was his willingness to help. No matter how busy he was, he always found the time to answer questions, troubleshoot issues, or point us in the right direction. He was incredibly approachable, patient, and always greeted everyone with a smile, making it easy to reach out whenever you needed support.
Theo is a true team player whose positive attitude and dedication make a real difference. Any team would be lucky to have him, both for his technical expertise and for the kind of person he is.
Alex Vázquez MartínezSenior Software Engineer at Unity