Founders who rebuilt their app from scratch — was it worth it?

About eighteen months into our product, we hit a wall that wasn't a feature problem. Every new thing we shipped took roughly three times longer than the last comparable one. Bug fixes kept reopening. Two engineers had built quiet, undocumented workarounds around the same broken assumption in our data model, and neither knew the other had done it.

The obvious answer was a rewrite. We didn't do it — not immediately. We spent a month arguing about it instead, which in hindsight was the most useful month we spent that year, because it forced us to name the actual problem: it wasn't the codebase. It was one early decision about how we modeled user accounts that everything else had been built to work around.

We ended up doing a partial rebuild. Roughly 40% of the code, the part that touched that assumption. Took four months instead of the fourteen a full rewrite would have taken. Shipping slowed but never stopped.

I still don't know if that was the right call. A full rewrite might have cleared out debt we're still paying for. Or it might have killed us — the graveyard of startups that spent a year rebuilding while a competitor shipped is not small.

So I'm curious about the other side of this:

• If you did a full rewrite, did it actually solve what you thought it would? Or did the same problems resurface in new syntax?

• If you didn't, what made you decide against it — and do you regret it?

• For anyone who rebuilt while still serving users: how did you handle the migration without breaking trust?