I have experience with 3 -

Penrod: Worked for them, their culture is pure propaganda. They also have what I call a “flipping houses” mentality - which means they seem to care about winning a project and then they do less than ideal work because they don’t care about follow-up. I have a friend who also used them as a partner and had a poor experience.

Coastal Cloud: Very literal about requests and deliver MVP (Minimum Viable Product) throughout the project. This lead to wasted cycles discussing how things should be done and what the big picture was over and over. This may be because their handoff from the people you talk to -> the people who do the work was flawed. Not a poor experience like Penrod but just a “C” student.

Slalom: only interaction is anecdotal. Worked adjacent to these guys for about 9months. Having never seen or been involved in their project - I did only hear positive things.

TLDR: I’d consider Slalom / Silverline / Estarei / and then Coastal Cloud in that order. Penrod is a trap.

Look for someone who wants to be there for project 2, 3, 4, etc. Even if you don’t have those in the pipeline it will mean that they are going to do work they are prepared to maintain or build upon rather than dumping a mess in your lap / another partner’s lap.