I definitely understand reluctance to trust new data formats. I will say though that we have been using Zstandard in production at Facebook since well before 1.0 and trust it completely for both data at rest and data in flight. Since 1.0, we've widened that even further to many different parts of the company.

To that end, every release (and pretty much every commit) undergoes significant testing. We also fuzz test heavily and have significant regression tests in place constantly looking at corner cases and verifying known prior bugs stay fixed. It's impossible to prove there are no issues, but so far we've put a lot of effort into being as reliable as possible and seen that play out well in our production environments. We trust it.