Building an embedded product on top of a large Open Source codebase like WPE WebKit is only the first step. The real challenge is keeping its quality stable as thousands of lines evolve and hundreds of changes land every week across multiple platforms.

In such an environment, errors and regressions are inevitable. What matters is detecting them quickly, understanding their impact, and reacting before they propagate further. This talk focuses on the engineering work that makes this possible, an effort that is essential yet often invisible.

Using WPE WebKit as a case study, we will explore how quality becomes a continuous engineering effort rather than a final validation phase and how CI and QA infrastructure, testing strategies, and processes (e.g. stabilization windows) sustain upstream development while supporting downstream deployments. We will show how these feedback loops reinforce each other and why aligning upstream and downstream processes is critical to keep quality stable over time.

This talk targets engineers, maintainers, and technical leaders working on large Open Source projects, as well as teams building products on top of them who need to sustain quality at scale.