Multi-Provider SMS Gateway Integration
SaaS / Authentication
Challenge
A multi-tenant SaaS platform required SMS OTP authentication and transactional notifications across 12 countries. The single SMS provider in use had a 6–8% delivery failure rate in several target markets, causing failed logins and support tickets from users who never received their codes.
Solution
An abstraction layer over three SMS providers: a primary provider and two country-specific fallbacks. The routing logic selects the optimal provider per destination based on historical delivery rates. Failed sends trigger automatic retry through the next provider, with delivery confirmation tracked in PostgreSQL and exposed via an admin dashboard.
Results
OTP delivery success rate improved from 92% to 99.1% within two weeks of dual-provider fallback activation. Monthly SMS cost decreased by 18% by routing to cheaper providers in markets where the primary provider performed acceptably. Support tickets related to failed OTP delivery dropped to near zero.