When we decided to add in-app chat to the Capital One UK app, the challenge wasn't the feature itself — it was everything around it.

The problem with vendor selection

Most vendor evaluations end up as a PowerPoint exercise. We did it differently: we prototyped with three vendors in parallel, running the same set of edge cases through each. Security requirements alone eliminated two of the three within a week.

Coordinating across 5 teams

The hardest part of any large feature isn't the code. It's the interfaces between teams. We ran weekly alignment sessions with product, cyber, mobile, services, and connect — not status updates, but working sessions where blockers got resolved in the room.

What we'd do differently

Invest more in the contract between teams upfront. The integration points that caused the most pain were the ones we'd left ambiguous longest.