Not an active participant myself (well, at least not in public), but these related blog posts were interesting:
[https://chameth.com/2018/12/09/over-the-top-optimisations-in-nim/](https://chameth.com/2018/12/09/over-the-top-optimisations-in-nim/) ([repo](https://github.com/csmith/aoc-2018)) [https://blog.dataforce.org.uk/2018/08/advent-of-code-benchmarking/](https://blog.dataforce.org.uk/2018/08/advent-of-code-benchmarking/) ([scoreboard](https://dataforce.org.uk/aocbench2018/))
