CI Build Flow Aspects

Transferring intermediate results from a dependent job step to another job step can be implemented in multiple ways:

• artifacts (gitlab-blessed, but size-limited and slow?)
• shared filesystem (→ currently used, but a rather specific setup)
• caches (caches being "best effort" is a nice property… not sure if good if we require them to be reliable)

→ An investigation of the precise limitations of the "gitlab-blessed" method would be helpful.