Yeah, those wins are great. It's really about the level of detail that you assume they want. "I improved the deployment time" is an effect of a technical change, not a technical change in itself. There are a lot of people who could improve the deployment time just by switching to a faster build backend or doing some other small change that has big dividends. Is that a "technical accomplishment"? Sure, and it has big wins, but if the answer is just "I installed Jenkins" then it kind of takes the oomph out.
And big wins like that are usually compacted pretty early on. If you can get orders of magnitude improvements left and right, it means that something about the company's management is off.
It's also not a good question for an interview because it's a hard basis for comparisons. Perhaps another candidate knew how to improve the build/deployment pipeline, but he was blocked by political interference. He wouldn't be able to say "I sped up the pipeline 6x.", but he could talk about his plans to do so with a question more oriented to the task, e.g., "How would you build your dream deployment pipeline?"
That's what I mean when I say they're looking for something spectacular. Some people can say they saved their company or made a change with massive ripple effects, which is not necessarily aligned with the technical difficulty of that change and may cause some candidates to elide mention of it entirely, and some people can't make such big assertions, not because they're not skilled enough, but because the opportunity and/or priority wasn't there.
If you want to know about business gains and side effects of technical work, ask "How did your work help your employer?" If you want to know about technical work itself, ask relevant lines of questioning.
Anyway, I think we're basically splitting hairs here. It's just about what level you're choosing to process the question on, and it seems everyone agrees that it's best to take a very superficial interpretation and allow them to inquire further as necessary. I just don't think it's a good interview question.