Custom booking systems
Bookings, payments and ticket scanning, plus the logic that decides who goes where: which group gets which slot, what's still available, what a deposit and instalment plan looks like for this particular customer. And the admin side, where your team sees the real state of things and makes changes.
Off-the-shelf platforms and e-commerce plugins do the simple version of this well: a product, a date, a card payment. The trouble starts when your bookings have rules of their own. At that point the platform either can't do it, or you end up with a chain of extensions and subscriptions, and staff working around the software instead of with it. I build booking systems around those rules instead, the system does the allocating rather than a person with a spreadsheet, and the whole thing belongs to you.
One I've built
Party Hard Travel takes tens of thousands of bookings a season through a system I built and manage. It takes the payments and instalments, places every traveller into the right events, and gives the office staff and the resort reps their own tools, down to the wristband at the door. Read the case study.
What's usually involved
Live availability, packages and add-ons, and deposits and instalments through Stripe. Allocation with your constraints written in. An admin area for bookings, changes and refunds. Ticket scanning and check-in from a phone. Connections to your email marketing and accounts software, so nothing is typed in twice.
Off the shelf or custom?
If a platform does what you need at a price you're happy with, I'll tell you to use it. A custom system makes sense when your rules don't fit, when the platform's fees have grown with your volume, or when you're paying for several tools to do one job. That's what the discovery sprint is for: a few days with your real data, and a firm price at the end.