1. It took a lot of time to build something robust enough that teams were willing to swap out their critical infrastructure for. There is a big different between your marketing automation system experiencing an issue vs. the system that sends out 2FA/magic link messages.

2. I really wanted to iterate on our API until it felt "HN worthy." That also took time. (For reference, Stripe did their HN launch a couple years post-YC for the same reason.)