I have some thoughts on this (in the context of modern SaaS companies).
The most expensive parts of fixing a bug are discovering/diagnosing/triaging the bug, cleaning up corrupted records, and customer communication. If you discover a bug in development or even better while you are coding the function or during a code review you get to bypass triaging, customer calls, escalations, RCAs, etc. At a SaaS company with enterprise customers each of those steps involves multiple meetings with your Support, Account Manager, Senior Engineer, Product Manager, Engineering Manager, Department Manager, sometimes Legal or a Security Engineer and then finally the actual coder. So of course if you can resolve an issue (at a modern SaaS company) during development it can be 10-100x less expensive just because of how much bureaucracy is involved in running a large scale enterprise SaaS company.
It also brings up the interesting side effect of companies adopting non-deterministic coding (AI Code) in that now bugs that could have been discovered during design/development by a human engineer while writing the code can now leak all the way into prod.
The most expensive parts of fixing a bug are discovering/diagnosing/triaging the bug, cleaning up corrupted records, and customer communication. If you discover a bug in development or even better while you are coding the function or during a code review you get to bypass triaging, customer calls, escalations, RCAs, etc. At a SaaS company with enterprise customers each of those steps involves multiple meetings with your Support, Account Manager, Senior Engineer, Product Manager, Engineering Manager, Department Manager, sometimes Legal or a Security Engineer and then finally the actual coder. So of course if you can resolve an issue (at a modern SaaS company) during development it can be 10-100x less expensive just because of how much bureaucracy is involved in running a large scale enterprise SaaS company.
It also brings up the interesting side effect of companies adopting non-deterministic coding (AI Code) in that now bugs that could have been discovered during design/development by a human engineer while writing the code can now leak all the way into prod.