From the FAANG, Amazon strikes me as the one using most open source code while at the same time not having much to show as open source - firecracker is a (relative) toy.

Firecracker has 13K stars on Github [1]. I'm not in this space. Why does a toy have so much activity (issues, pull requests) and stars?

1 - https://github.com/firecracker-microvm/firecracker