Fintech
WhatsApp OTP Live on Signup the Same Afternoon
Backend team at a lending appWhatsApp, SMS, Verify API
The Challenge
Signups needed a verified phone number, but the SMS vendor asked for weeks of paperwork and its errors gave no clue why a code had not arrived.
What They Did
- 01
One Key
A developer created a test key in the console and sent a code to their own phone with curl.
- 02
Two API Calls
One call sends the code over WhatsApp or SMS, a second call checks what the user typed.
- 03
Live the Same Day
They switched to a live key the same afternoon, with logs showing every code sent and checked.
The Result
- Phone verification went live on signup the same afternoon.
- Codes go out over WhatsApp, with SMS for everyone else.
- Clear errors and logs mean support can see exactly what happened.
In their words
“I got a WhatsApp OTP on my own phone from a curl command in three minutes. One key, clear errors, and logs that show exactly what happened.”
