I think you are on to something. But I also think this sort of system lends itself to not needing really good LLMs to do impressive things. I've noticed that the quality of a lot of these LLMs just gets worse the more datapoints they need to track. But, if you break it up into smaller and easier to consume chunks all the sudden you need a much less capable LLM to get results comparable or better than the SOTA.
Why pay extra money for Opus 4.7 when you could run Qwen 3.6 35b for free and get similar results?
Its one things for a model to be very clearly instructed to add a REST endpoint to an existing Django app and add a button connected to it on the front vs "Design me a youtube". The smaller models can pretty dependably do the first and fall flat on the second.
You prompt for what you want it to do, and it will write eg. python scripts as needed for the looping part, and for example use claude -p for the LLM call.
You can build this in 10 minutes.
I don’t use a cloud platform, so I can’t comment on that part. I‘d say just run it on your own hardware, it’s probably cheaper too.
You can have the AI design the custom harness in advance. It's not especially hard work! In fact, the AI could even come up with the workflow itself; it's a different and much simpler problem than trying to stick to it after-the-fact, with a filled-in context.
https://github.com/notque/vexjoy-agent
I would prefer that be deterministic though. This thread has me considering what if anything I can do to make it forced. Like, I could do it with hooks, but that's not elegant at all.
I also think having granular, tightly controlled steps is much friendlier to implementing smaller, cheaper, more specialized models rather than using some ginormous behemoth of a model that can automate your tests, or crank out 5 novels of CSI fan fic in a snap.