T-Mobile · Account security · 2025
Network authentication
Fraud pathways closed, with 50–85% of customers completing sign-in.
Work under NDA. Visuals are recreations; details are available in conversation.
- 50–85%
- sign-in completion by platform
- 3
- platforms designed as one system
- 4
- partner teams aligned on every step
The problem
Every sign-in is a security decision.
The team had found ways fraud got into accounts. The fix had to hold on three platforms without locking customers out.
The approach
Four partners, one set of trade-offs.
I mapped the multi-device flows in FigJam with security, engineering, legal and accessibility, and pressure-tested options in a design swarm.
The decision
Each added step had to earn its place.
Every step blocks fraud and gives customers a reason to quit.
- I chose
- Showing partners what each step protected and what it cost in completion
- I gave up
- Maximum friction “just in case”
- Why
- Security that customers abandon protects no one
What shipped
One authentication system, three platforms.
The same steps and language wherever customers sign in, with platform-specific details.
Reflection
Make the trade-offs visible.
Authentication is mostly negotiation. Bringing security, legal and accessibility in early moved it fastest.