Within the BlueOcean Pipeline View the blue time information could be added to the graphs nodes to clearly highlight to a developer the slowest part of their CI pipeline.

I have attached a mock-up of what this may look like:

We may be worried about cluttering the pipeline view with too many visuals, however the final missing component may just be the build information. If there is additional information that would be useful to add, we could potentially optimise the UX for that additional data, but for now I think the time spent on each stage would be useful.