As someone that has used Dagger a lot (a previous daggernaut / ambassador dropped off after LLMs was announced, and was changing jobs at the time. implemented it at a previous company across 95% of services, built the rust sdk) the approach was and is amazing for building complex build chains.
It serves a place where a dockerfile is not enough, and CI workflows are too difficult to debug or reason about.
I do have some current problems with it though:
1. I don't care at all about the LLM agent workflows, I get that it is possible, but the same people that chose dagger for what it was, is not the same audience that runs agents like that. I can't choose dagger currently, because I don't know if they align with my interests as an engineer solving a specific problems for where I work (delivering software, not running agents).
2. I advocated for modules before it was a thing, but I never implemented it. It is too much magic, I want to write code, not a DSL that looks like code, dagger is already special in that regard, to modules takes it a step too far. You can't find the code in their docs anymore, but dagger can be written with just a .go, .py or .rs file. Simply take in dagger as a dependency and build your workflow.
3. Too complex to operate, dagger doesn't have runners currently, and it is difficult to run a setup in production for CI yourself, without running it in the actions themselves, which can be disastrous for build times, as dagger often leads you into using quite a few images, so having a cache is a must.
Dagger needs to choose and execute; not having runners, even when we we're willing to throw money at them was a mistake IMO. Love the tool, the team, the vision but it is too distracted, magical and impatient to pick up at the moment.