Accept fast, validate later
Quote
you can't really do that and make the call fast. Because you're gonna block while you're sitting here waiting on the server to pull the feed and do all these crazy checks.
Episode 5: Episode 5 00:36:03 (play audio from this timestamp, opens in a new tab)
Voice-matched
Summary
Ideally, when a feed URL is submitted you'd check it isn't a 404, parse the XML, and confirm it has enclosures. But doing that synchronously blocks the call while the server pulls the feed. The Index trusts vetted key holders, accepts the submission fast, and runs the heavy checks afterward in the aggregator.