The boring bits of agent engineering

The fun part of agents gets the attention, but most of my time has gone into the unglamorous part, which is keeping the runs from falling over once they're doing real work in production. The stuff that keeps tripping me up: * actually seeing what a run is doing while it's mid-flight, instead of reconstructing it from logs afterward * resuming a failed run from where it died, so I'm not re-running the expensive model calls that already succeeded * getting that progress out to the UI without standing up a whole separate status thing After hitting these enough times I started building a small thing to handle the run side of it (link in comments if you're interested, very open to suggestions), so that we don't have to re-apply the same pattern to all upcoming projects (or more painfully, refactor projects that have not taken reliability into consideration from the start). Most of it honestly feels like classic distributed-systems stuff, nothing new. What I'm less sure about is whether agents actually change anything, since the steps aren't a fixed graph and half of them are model calls you can't cleanly replay. Curious whether that matters in practice or the old playbook still covers it. Two things I'd genuinely like to know: 1. What's the piece you end up rebuilding for every agent or long-running job? 2. Has anyone found something off the shelf that already handles this well in prod? Temporal/DBOS/something else?