miniblog.

Difftastic spends a remarkable 49% of its runtime just reading and writing to a FxHashMap of ~1 million items. This hashmap stores the predecessor vertex when calculating the shortest route. I'm running out of ideas. I can't use perfect hashmaps, are there other speed tricks?

Flamegraphs are an indispensable tool, but sometimes I overuse them. Here's an example for difftastic -- it spends most of the time computing the shortest path. I was able to make the diff graph smaller, making difftastic much faster -- but the new flamegraph looked the same!

Which languages have the shortest/longest half-life? If you didn't write any code in language X for five years, how easily could you continue maintaining an old project?