There are good reasons to dislike Telegram, but having "just" 30 engineers is not one of them. Software development is not a chair factory, more people does not equal more or better quality work as much as 9 women won't give birth to a baby in a month.

Edit:

Galperin told TechCrunch. “‘Thirty engineers’ means that there is no one to fight legal requests, there is no infrastructure for dealing with abuse and content moderation issues.”

I don't think fighting legal requests and content moderation is an engineer's job. However, the article can't seem to get it straight whether it's 30 engineers, or 30 staff overall. In the latter case, the context changes dramatically and I don't have the knowledge to tell if 30 staff is enough to deal with legal issues. I would imagine that Telegram would need a small army of lawyers and content moderators for that. Again, not engineers, though.