Feels harsh to jump on them for it, but it seems like they forgot the job spec when doing the take home. From that list Kagi wants to confirm:

- Proficiency in Go - Strong understanding of scaling and maintaining backend systems - Solid understanding of containerization technologies like Docker

Nailing the take home would require a project that demonstrates all three. Of those I think they maybe do okay on the second one, though offloading to paid services is maybe cheating a little there. I don't think they do well at either of the other two though.

From the detailed spec, one might expect the project to demonstrate those things, but the code as submitted just doesn't.