I have spent eleven years designing software, most of it inside product teams rather than agencies. That is where I learned that the hardest part is rarely the visual idea, it is the thousand small decisions that have to hold together after launch.
So I work with one team at a time, sit in your standups, and write the specs in the same language your engineers use. The result is less impressive in a portfolio and considerably more useful on a Tuesday.
One project at a time
Your work is not queued behind another client.
Design in the real thing
Screens are explored inside your product, with real content.
Handover is the job
States, edge cases and copy documented as carefully as the happy path.
Say the difficult thing
If a flow will not work, you hear it early rather than late.