For example, 1.7’s re-implementation of the working copy status API used by Cornerstone is now 10x slower than the same API in Subversion 1.6. It provides the same output, but what previously completed in 200 ms now take over 2 seconds. We don’t think this kind of performance degredation is acceptable and spent some time migrating Cornerstone to use newer and faster APIs.

[…]

We came to the conclusion that we would have to re-think certain core aspects of how Cornerstone interacts with Subversion. The constraints introduced by SQLite make it substantially more complicated to use Subversion’s APIs from multiple threads. We ended up having to re-design the way in which key data structures are allocated and managed by Cornerstone.

The first step is fully admitting that the code you write is riddled with errors. That is a bitter pill to swallow for a lot of people, but without it, most suggestions for change will be viewed with irritation or outright hostility. You have to want criticism of your code.