Meta Job "build all"

I try to get an picture of the possibilities in CI/CD in gitlab.

Our current Jenkins Workflow (we have only one configurable pipeline):

  1. Select App (1-10).
  2. Build-Script compiles Apps selected in 1).
  3. Run tests
  4. Deploy apps.

There’s also an “build” all, which is faster, because we invoke the compiler only once, but without any filter instead of invoking 5-10 times.

What i know so far is, it’s not possible to have runner parameters as checkbox-list/dropdown-list. So instead, the way to go is to select a specific job (or pipeline?) that respresents a specific app.

So, let’s say i create 10 Job’s (each for repsresents an app). So, is “build all” then a seperate job? How to trigger than the “deploy” in Step 4)? Can a job invoke another job depending on script-logic?