In some companies, code is merged at a rapid rate by multiple teams with minimal testing and somehow the number of bugs is kept to a minimum.
In other companies, this leads to chaos and terrible situations. Root-causing leads to no useful insights and people feel they are put on the spot about a problem (chaos) that is outside of their control.
What is the key difference between these two kinds of companies, ones that can thrive with rapid coding and merging versus those that cannot?
Put another way: What are the failure modes of rapid code merges and what can protect against such failures?