The story

A non-profit was preparing a huge reunion event — over a thousand guests from all over the country, several attendee categories, and organized train transfers from four cities. Eventbrite-style services couldn’t model the real constraints: limited train seats per departure city, separate flows for guests and staff, and an ops team that needed live numbers, not exported spreadsheets from a third-party dashboard.

I built the whole thing as a single self-contained WordPress plugin.

How it works

Tickets as a custom post type. Every registration becomes a ticket with a unique prefixed number, category, guest count, and travel details — all queryable with plain WordPress APIs.
Train seat capacity per city. Each departure city has a seat limit, editable by admins right in the stats dashboard. A public AJAX endpoint returns live seat availability, so the registration form disables a city the moment it sells out. Offline registrations (people signed up by phone) are added as “manual seats” on top of the automatic count.
Login without passwords. Guests check and retrieve their ticket by phone number. Staff members verify themselves with a one-time code sent to their corporate email — the OTP is domain-restricted, stored in a transient with attempt limits, and expires in 10 minutes.
An ops dashboard inside wp-admin. Live statistics by category, city and status, inline ticket editing, and one-click CSV export with every field the logistics team needs — names, phones, transfer city, guests, kids, registration date.

The interesting part

The whole system is one plugin file — deliberately. For an event with a fixed date and a small ops team, deployability beat architecture: drop the file in wp-content/plugins, activate, done. No build step, no migrations, no dependencies. It handled the full registration wave without a hiccup.