Went through this exact same process not too long ago. Honestly, the thing that actually moved the needle for me was an article that completely changed how I was framing the decision.
Turns out clutch ratings and hourly rates are pretty much noise in fintech. The stuff that actually matters is whether a team is genuinely compliance-ready versus just knowing the buzzwords, and whether they have the judgment to build custom versus just wiring in Stripe or Plaid where it makes sense.
The client retention angle was the one I hadn't thought about at all — if a fintech dev shop is holding 85-90%+ of their clients year over year, it means their stuff is actually running in production and not falling apart six months later. That's a lot harder to fake than a polished case study. The article also does honest breakdowns of around 10 companies and gets pretty specific about who each one is actually a good fit for, which saved me a ton of back-and-forth.
Dropped the link below if anyone wants it: interexy.com/top-fintech-app-development-companies