tasks:
  a:
    commands:
      - echo a
      - sleep 0.5
  b:
    commands:
      - echo b
      - sleep 0.5
    depends_on: [ a ]
  c:
    commands:
      - echo c
    depends_on: [ a ]
  d:
    commands:
      - echo d
    depends_on: [ b, c ]
working_dir: /custom/directory
stdout: none
stderr: none