Accept Data In, Be Strict Going Out

00:30:38 — Accept Data In, Be Strict Going Out

In systems with fuzzy boundaries, a key defensive principle is to be very accepting of incoming data (return validation errors rather than choking) so you don’t break your callers, while being strict about the structure of data you send out so you don’t break your dependencies. The metaphor is tolerating insults without getting angry while being careful never to insult others.