Case study · Mobile banking · via BCG
A year redesigning a major Indian bank’s mobile app with BCG: payments, login, and the design system behind them.
Navigation was confusing, key details were missing when people needed them, and the flows didn’t match Google Pay or Paytm, the apps customers already used every day. The bank had no brief, just a feeling the app wasn’t good enough.
It’s used daily, so it was a fair test. Instead of new patterns, I used the ones people already trust from Google Pay and Paytm. When moving money, familiar feels safe.
The bank wanted to advertise its savings rate inside the transfer flow.
An ad in the middle of a payment distracts people when they most need to focus.
Removing it wasn’t an option, so I argued to make it smaller and keep it out of the main task.
It shipped small and quiet. The first time the client went with my reasoning over their own.
The test worked. We got thirteen more journeys, including onboarding, payments, savings, credit cards, mutual funds and spend tracking.
Everyone sees the login screen, which makes it the easiest place to lose people.
One screen, one way in. If your details didn’t match, you were stuck.
A forgotten username, a new phone or a new SIM locked people out of their own account.
Four ways to verify: Customer ID, PAN, account number or debit card. SIM checks run in the background.
Set an MPIN once, then log in with a fingerprint every time after.
We locked shared components and wrote down the patterns. Builds and reviews got faster.
It also helped with the client. They often asked for “something different”. The system gave us a clear reason to say no, and a quick way to say yes when a change made sense.
We handed off to the bank and BCG before launch data was available.
Trust comes from delivering. Good work earned me the right to push back, and taught me to pick which fights matter.
A design system is a tool, not a chore. It sped up the team and gave us a clear way to handle client requests.