App Store Connect / Play Console
The publisher dashboards at Apple and Google where builds land, listing copy is edited, testers are invited, and your money shows up.
See it
What it is
The two publisher dashboards. App Store Connect is Apple's, Play Console is Google's, and between them they hold everything that happens after the build compiles: uploaded builds, versions and release tracks, listing copy and screenshots, tester invitations (TestFlight on one side, internal and closed and open tracks on the other), in-app purchase and subscription products, pricing, privacy declarations, install and revenue reports, and your payout and tax details.
Same ideas, different vocabulary on each side, which is most of the confusion. Both also have APIs (the App Store Connect API and the Play Developer API), so once the manual flow makes sense you can hand uploads, metadata, and rollouts to CI and stop clicking through either one.
Gotcha: the boring account plumbing blocks releases silently. Only the Account Holder can accept a new paid apps agreement or change banking details, and until that is accepted your paid downloads and in-app purchases simply do not work. Uploaded iOS builds also need several minutes of processing before they are selectable, and Play wants an app bundle (.aab) rather than an APK for new apps.
Ask AI for it
Walk me through taking a new app from zero to a first tester build in [App Store Connect / Google Play Console], for an app built with [stack]. Give numbered steps naming the exact screen and button at each point: creating the app record (bundle ID or package name, primary language, default listing), uploading the first build, waiting out processing, completing the minimum required declarations, and inviting internal testers. Then show the equivalent command using [fastlane / the App Store Connect API / the Play Developer API] so I can automate it in CI. Call out any step that only the Account Holder can do.