after 9 months with sst at canopy, with an engineering team of about 12+ and growing, we've encountered quite a few pains too! most of them pertains to CDK and AWS itself though, and not SST itself.
we love sst, but here's a few pain points,
1. changing resources shared among different stacks often lead to some orphan export value that's suck. sometimes this means we have to jump into cfn to remove values manually, or find a workaround
2. we moved off seed to github actions to move away from git-branch based deployment. deployment became a bit slower but now we can have manual approval checks to deploy to different stages instead of relying on merges b/t branches
3. setting a unique stage per developer was a problem that we made a customer solution to solve, but i think sst solves it now?
fun story: i accidentally almost took out our entire infrastructure like an idiot because i clicked delete app + resources in Seed. thought it was still clicking thruogh a stage only haha.