The speaker starts by apologizing for technical difficulties and introduces themselves as Marco Mäkinen, a developer who has worked on the ENO-DB code for nearly 20 years. The focus of the talk is on one of Marco's pet hates in ENO-DB, the change buffer. The change buffer was developed as a way to reduce the read-write hits on spinning disk hard drives. It works by writing changes to a separate buffer instead of directly to the page, reducing the amount of disk movement required. However, Marco believes that the change buffer is causing bugs and explains the various problems it can cause, such as right amplification, where certain operations require more writes to the disk. He also talks about difficulties in testing and reproducing the bugs caused by the change buffer. Marco discusses how the debugger RR has been helpful in debugging the bugs and shares an example of a bug that was found and fixed. He concludes by discussing the importance of writing assertions in code and mentions that MariaDB has made some changes to mitigate the issues caused by the change buffer.