Webhooks, on both providers
Until now every change reached your board by us going and asking for it on a schedule. Now your provider can tell us.
GitHub and GitLab webhooks are both supported, and registration is automatic — connect a project and we register the hook.
The GitLab side needed more care than expected. Registering a project hook requires a token with the right scope, and if the token does not have it, GitLab does not refuse loudly. Registration can appear to succeed while producing a hook that never fires, which is the worst of both worlds: a board that looks connected and quietly is not. So registration checks the scope up front, across your linked GitLab accounts, and tells you when nothing available can do the job.
The scheduled sweep has not gone anywhere and is not going to. Webhooks get dropped, providers have incidents, and a system with only one path for changes to arrive has a single point of silence.