2012.03.18 in #34Faster DBD::Oracle if you are using a threaded Perl
Martin Evans tells about a huge change in DBD::Oracle coming from Dave Mitchell that will provide a substantial speed-up. It's interesting to see that he suspects the debugging to have caused the slower performance in threaded perl.
2012.10.03 in #63Fixing Perl5 Core Bugs: Report for Month 31
The report of Dave Mitchell contains a couple interesting issues with the regex engine of perl. For example you probably knew that using $` or $' will make your regexes slow. Did you also know that using these variables can make your regexes correct? It has been fixed now. (I'll let you guess which part was fixed.).
2013.04.22 in #92Fixing Perl5 Core Bugs: Report for Month 37
This is the TPF grant report of Dave Mitchell. He did not have much time this month and he mainly worked to unblock the release of perl 5.18.
2013.06.10 in #99Fixing Perl5 Core Bugs: Report for Month 39
The report of Dave Mitchell. Apparently he has used all the allocated hours (and money) from his previous grant. You will see a new grant request from him soon.
2014.03.14 in #138A Faster Perl Runtime in Tiny Steps
Apparently now Booking.com is sponsoring Dave Mitchell directly to improve the performance of perl. Steffen Muller explains the changes Dave made in a human readable way.
2014.12.15 in #178Maintaining the Perl 5 Core
Dave Mitchell's monthly report for his work on the Perl 5 core, funded by a grant. The main item of note was his awesome work on a benchmarking tool.
2015.05.14 in #199Maintaining the Perl 5 Core: Dave's monthly report
There's probably not much in this, relatively short, list that most readers will understand, but I think it's important we all acknowledge Dave's work. This is a key part of the grind that keeps Perl 5 moving forward.
2017.06.07 in #307Dave Mitchell's grant report for May
Dave's biggest piece of work in May was reworking the sprintf implementation, in the process fixing bugs and making it faster.