Sellnexia — AI WhatsApp Lead Capture Platform
Marketing site and conversion funnel for a B2B SaaS platform that captures and qualifies leads 24/7 via AI-powered WhatsApp automation — with a free-trial flow and live admin-driven coupons.
What needed solving
Small businesses, clinics, coaching institutes and real estate firms lose 50–65% of their enquiries — replies are slow, follow-up is manual, and leads leak out of WhatsApp chats with no system to capture or qualify them. Existing CRM tools are too complex and not built around the way Indian SMBs actually communicate.
How I solved it
Built the complete marketing site and conversion funnel for Sellnexia — a SaaS platform that deploys an AI agent on WhatsApp to answer customer queries and capture qualified leads 24/7. The site includes a no-credit-card free trial flow, a live admin-driven coupon rotation system, tiered pricing with GST messaging, and an enterprise inquiry form — all wired to the live product backend via a secure server-side proxy.
A look at the product
Key Features
- Free 30-day Welcome plan funnel — no credit card required, real WhatsApp number provisioned, live AI replies from day one
- Dynamic coupon section — pulls active coupons from the admin panel, rotates every 5 seconds, cached for 1 minute via ISR so admin changes go live within a minute
- Tiered pricing page with plan comparison matrix, GST messaging, and coupon discount display
- Enterprise inquiry form with email confirmation and backend sync for high-value B2B leads
- Secure server-side proxy route — backend credentials never exposed to the browser
- Graceful degradation — 0 coupons shows generic text, 1 shows a static card, 2+ rotates automatically
Architecture
- 01Next.js 14 App Router with ISR (revalidate=60) on the coupon endpoint — admin changes reach the site within 1 minute with zero API hammering
- 02Server-side Route Handler acts as a proxy to the Express backend — shared-secret header authentication, fail-quiet behaviour on backend errors
- 03Node.js + Express backend on AWS EC2 with PM2 process management and Nginx reverse proxy
- 04MongoDB via Mongoose for plan, coupon, and inquiry data storage
- 05Razorpay payment integration for plan upgrades and subscription billing
- 06Vercel deployment with GitHub CI/CD — push to main triggers automatic production deploy
Results & Outcomes
26/26 pages build cleanly with zero TypeScript errors
Live coupon rotation confirmed on production — single admin change reflects site-wide within 60 seconds
Single-source-of-truth coupon flow eliminates all manual website edits for promotions
Free trial funnel live at app.sellnexia.com with real WhatsApp number provisioning
Delivered as solo developer in 6 weeks end-to-end
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