BeSends — omnichannel messaging SaaS

What I built

• WhatsApp Cloud API across several Meta business accounts plus QR-linked devices, with capacity-aware routing that spreads traffic by each number's remaining daily limit
• Compliance guard: opt-out list, 24-hour service window, template-only cold sends, automatic pause on Meta rate and quality signals
• Retry queue with 5→360 minute backoff that only retries transient failures and refunds credits on permanent ones
• Paddle Billing (subscriptions + one-off packs) and bKash checkout, coupons, credit packs that expire oldest-first, pay-as-you-go
• Admin diagnostics page that reads live logs, groups errors and suggests the fix for each

Hundreds of OTP and notification messages a day for corporate and university clients