The title is misleading - it's actually about how and why they did end up writing their own db. From the article:
> There’s an old adage in software engineering — “never write your own database”. So why did the OneNote team go ahead and write one as part of upgrading OneNote’s local cache implementation?
> There’s an old adage in software engineering — “never write your own database”. So why did the OneNote team go ahead and write one as part of upgrading OneNote’s local cache implementation?