07 - Event and Participant Management: The Platform Core

The central module of Play The Event: event lifecycle with state machine, 6 participant roles, complete RSVP system, check-in/check-out and external guest management.

What you'll learn

• Events follow a strict state machine with 9 states, enforcing business rules at the domain level
• The EXPENSE_SPLITTING gate ensures expenses are always settled before an event is completed
• Four participant roles (ORGANIZER, CO_ORGANIZER, ATTENDEE, VIP) with clear permission boundaries
• Six RSVP states with invitation expiry, auto-accept for organizers, and response tracking
• Dual check-in system: registered participants (boolean flag) and external guests (full entity)

This article is part of the Play the Event series on federicocalo.dev.

Read the full article

The complete article (14 min read) with code examples, diagrams, and practical exercises is available here:

➡️ 07 - Event and Participant Management: The Platform Core

https://federicocalo.dev/en/blog/pte-event-participant-management

By Federico Calò — Software Developer & Technical Writer