Current CI parallelization has high overhead because each test shard repeats installation and setup, potentially taking minutes.

“Like, the overhead of parallelization right now is very high. 'Cause, like, right now, like, in GitHub actions for instance, like we, we parallelize in, in the Modal, the test suite, right?”

“But, like, what that basically means is, like, now if you take your test suite and you split it up in two, like, now each of those shards both need to do all the installs and, and the test setup. Mm.”

“And that takes a long time. Like, it, it can take minutes. But let's say you can do the test setup once, and then you snapshot the container, and now you clone it, and now you can run the test suites independently.”