1mb isn't about being solo.

Plenty of one-man-bands work inside teams of 50.

They just operate differently.

Own the outcome, not just the task.
Ship without waiting for the green light.
Fix what breaks. No finger-pointing.

The team size doesn't matter.
The stance does.

"End-to-end ownership" sounds corporate.

Really it means:
You designed it. You defend it.
You broke it. You fix it.
You shipped it. You support it.

No handoffs.
No blame.
Just outcomes.