I’ve been building my docker image and pushing to an ecr repo using github actions. Is it better to use pulumi for this considering pulumi creates the repo in ecr?

Define "better"? ;) No, neither option is better. You can use Pulumi from workflows, there is a handy action available!

@little-cartoon-10569 I was just curious if there was any pattern that people are using…

We use the Pulumi action from GitHub. If your current approach is working and is not difficult to maintain, then there's no point in changing it. But if you need to update it, then Pulumi is a good way to go.