‘Developer-first Zapier alternative’ is an odd positioning, I think the point of Zapier is that it’s for non-developers mainly. Looking at the comments, though, it seems like there’s a need for something like this. Keen to see how you iterate and improve your positioning. Good luck!
My experience with Zapier is that you quickly hit a point where you’re building an ultra complex expression or manipulating json in a less than ideal editor. Also your zap is basically the ast of the code you would have written and grows quickly. Code is far more terse.
That said, long running durable workflow tools that are targeted at devs all have challenges. There’s room for a Goldilocks solution. I’d imagine temporal will win though.