Comment by sllabres

Yes, they are made with: http://www.brendangregg.com/flamegraphs.html and

https://github.com/brendangregg/FlameGraph

Useful site if you are on to perf/eBPF/performance things with many examples and descriptions even for other uses as e.g. memory usage, disk usage (prefer heatmaps here but they are nice if you want to send someone a interactive view of their directory tree ...).