VictoriaMetrics [1] is written entirely in Go. By default it uses canonical zstd library for compression (the library is written in C), but it supports pure Go mode when built with `make victoria-metrics-pure`. In this mode it uses zstd implementation written in Go [2].

[1] https://github.com/VictoriaMetrics/VictoriaMetrics

[2] https://github.com/klauspost/compress/tree/master/zstd#zstd