In person
Hard problems benefit from shared context.
The way we work is designed around the product we build.
The product we want to build is vertically integrated, and our core competency is building optimization using this entire stack.
We therefore work in person as much as possible as this increases communication bandwidth, since what we're building is inherently unclear.
Sometimes we have to compromise in order to have people above the bar we need. This is likely to mean opening multiple offices to do this.