Car Marketplace Platform -
50k+ Users, SSO & Coupons
A US automotive marketplace had a WordPress content site and a React app that couldn't talk to each other users had to log in twice. Added SSO, a dealer feature management portal, coupon engine and PDF report generation for 50,000+ registered users.
The Brief
A US automotive marketplace operated a WordPress marketing site and a separate React application. Users had to maintain two separate accounts and log in to each independently a major friction point that was hurting conversion. Dealers had no self-service portal to manage their featured listings. The sales team was manually generating PDF reports for dealers, taking 5+ hours per week.
The brief was to build JWT-based SSO across WordPress and React, a dealer self-service portal, a coupon and promotions engine, and automated PDF report generation while keeping both existing platforms fully operational.
"Our users hate logging in twice. Our dealers want to manage their own features without calling us. And our sales team spends all Friday generating PDFs there has to be a better way."
Project Phases
Designed a JWT-based SSO system. When a user logs in on either platform, a signed JWT is generated and stored in a shared cookie. Both WordPress (via a custom plugin) and the React app validate this token against a shared secret. Users now authenticate once a session on WordPress automatically creates an authenticated session on the React app and vice versa. Zero duplicate accounts.
Built a dealer dashboard in React dealers log in and self-manage: upgrade to featured listings, add highlighted features (financing, certified pre-owned, extended warranty), manage their profile and view listing analytics. Before this, all changes required a phone call to the sales team. Admin panel allows overrides and bulk operations.
Built a flexible coupon system promo codes with configurable discount types (percentage, fixed, free upgrade), expiry dates, per-user usage limits and dealer-specific codes. Admins create campaigns; dealers share codes with their customers. Analytics show redemption rates, revenue impact and top-performing campaigns.
Built an on-demand PDF report generator using a Node.js templating library. Sales team selects a dealer or listing set, clicks "Generate Report" and receives a branded, professionally-formatted PDF within seconds. Reports include performance stats, listing photos, pricing trends and comparison data. Saved 5+ hours per week of manual work. Full load testing, handover and documentation completed in week 16.