Stéphan Vuylsteke joined Brink in 2022 and works full time on Bitcoin Core development. In 2025, he deepened his involvement with the Bitcoin Kernel project, the effort to extract Bitcoin Core's consensus logic into a standalone, reusable library.

His contributions to Bitcoin Kernel earned praise from the project's lead developer, while he continued to provide reliable review across the broader Bitcoin Core codebase with 14 opened pull requests, over 700 review comments, and significant contributions to py-bitcoinkernel.

Stéphan hosted 8 London BitDevs socratic seminars in 2025, contributed to Bitcoin Optech, including authoring and reviewing content for the 2025 year-in-review special and joining as a guest on the Optech podcast. He also co-maintains the Bitcoin Core PR Review Club, an effort to cultivate the next generation of developers.

On behalf of our sponsors, Brink is pleased to continue funding Stéphan's work on the kernel project and his contributions to the broader Bitcoin Core codebase.

In 2026, Stéphan's top priority is continuing to extend and improve the Bitcoin Kernel public interface and taking py-bitcoinkernel out of alpha status with robust documentation, tests, and a changelog. He plans to help build out the broader kernel ecosystem by making the library useful for developers beyond Bitcoin Core. He'll continue providing review across the codebase, contributing to Bitcoin Core's maintainability and robustness, and working on outreach through talks, workshops, and contributions to Optech.

You can view all of his Bitcoin Core PRs here:
https://github.com/bitcoinbrink/website/blob/master/assets/files/2026-03-26-engineering-impact-report-2025/stickies-v_2025.md

And review comments:
https://github.com/bitcoinbrink/website/blob/master/assets/files/2026-03-26-engineering-impact-report-2025/stickies-v_2025_review_comments.csv

More from Bitcoin Core developers funded by Brink:
https://brink.dev/blog/2026/03/26/engineering-impact-report-2025/