When I was at Monzo, we didn’t buy an external core banking system - we just built our own and it ended up supporting 12 million customers.

So when I started working with US banks, I was baffled. Why is there a never ending list of systems like Silver Lake, DNA, and Signature?

As it turns out, they almost all belong to the big three providers: FIS, Fiserv, and Jack Henry.

To shed light on this, I spoke to Stacy Bishop, former sales lead at Jack Henry, to find out why banks don't just build their own.

We covered:

- Why choosing a big three provider is the safe career move for bank executives, even if they hate the service.
- The reality of deconversion fees - where banks have to pay to get their own data.
- How legacy cores stay dominant by handling the double letter US regulations so banks don’t have to.
- How banks are finally innovating by building alongside their legacy systems.
- The inside scoop of how core providers secure long term contracts with banks.
- Why the next 5–10 years will look nothing like the last 20.

If you’ve ever wondered why US banking tech feels stuck in 2005, this is the episode for you.

Starting a bank seems like one of the hardest things you could possibly do. David Jarvis, CEO of Griffin, did exactly that and walks me through the WHY and HOW of building a bank from scratch.

Getting a banking license is no joke! I thought I understood this from my Monzo days, but turns out I'd only scratched the surface.

In this episode, we get into:

- How the licensing process actually works - from the first phone call to the Bank of England through 4.5 years of iterative feedback
- Why every bank has a £1M monthly burn rate
- The reality of raising £50M before you have a single customer or £ of revenue
- What actually happens when you send a payment (there's probably another bank involved)
- Why Revolut, with 70M customers, is still fighting for a banking license

David also shared about the less glamorous bits of startup founder life, but you’ll have to listen to find out!

The In Control podcast explores the finance of everything, through conversations with people who’ve done it, built it, or experienced it firsthand. Join host Natasha Vernier, Founder of Cable, as she sits down with leaders, innovators, and experts across the financial industry to explore how it all really works. The focus is on learning aloud and making complex topics accessible.