We are building a complete RSVP & registration system for events like:
hackathons
meetups
workshops
competitions
conferences
Core Flow
User opens RSVP page
→ fills form (solo/team)
→ submits registration
→ backend validates + saves
→ status = Pending / Waitlisted
→ admin reviews
→ Approved / Rejected
→ participant check-in
🎯 Goals
System must be:
- Flexible (supports all event types)
- Secure (PII + Aadhaar handling)
- Scalable (10K+ registrations/event)
- Configurable (custom questions, rules)
- Production-ready (validation + workflows)
🧱 CORE MODULES
1️⃣ RSVP CONFIG SYSTEM
Purpose
Each event has its own configuration.
Endpoint
GET /api/v1/events/:eventId/rsvp-config
PATCH /api/v1/events/:eventId/rsvp-config
Features
enable/disable RSVP
start/end time window
allow solo/team
min/max team size
capacity limit
waitlist toggle
duplicate policy
custom questions
2️⃣ REGISTRATION SYSTEM
Endpoint
POST /api/v1/events/:eventId/rsvp
Modes
Backend Flow
validate payload (Zod)
→ load RSVP config
→ enforce rules
→ check duplicates
→ validate team logic
→ encrypt sensitive data
→ generate registrationNumber
→ assign status (Pending/Waitlisted)
→ save
→ audit log
3️⃣ VALIDATION SYSTEM (CRITICAL)
Must Validate
Basic
eventId required
leader fullName/email/mobile required
consents must be true
Team Rules
teamName required
teamSize >= 2
members = teamSize - 1
Solo Rules
teamSize = 1
members = []
Identity
- email format
- mobile format (E.164)
- Aadhaar = 12 digits (if required)
4️⃣ DUPLICATE & FRAUD PROTECTION
Prevent
duplicate email in same event
duplicate mobile
duplicate collegeId (optional)
duplicate inside same payload
Advanced
- block disposable emails
- OTP verification (optional)
- IP tracking
5️⃣ RSVP WINDOW & CAPACITY
Rules
reject before start
reject after end
Capacity Handling
if full → Waitlisted
else → Pending
6️⃣ STATUS WORKFLOW
Lifecycle
Pending → Approved → CheckedIn
Pending → Rejected
Pending → Waitlisted → Approved
Approved → Cancelled
Rules
- only Approved → check-in
- rejected cannot check-in
7️⃣ ADMIN SYSTEM
Endpoints
GET /api/v1/events/:eventId/registrations
GET /api/v1/events/:eventId/registrations/:id
PATCH /api/v1/events/:eventId/registrations/:id/approve
PATCH /api/v1/events/:eventId/registrations/:id/reject
PATCH /api/v1/events/:eventId/registrations/:id/waitlist
PATCH /api/v1/events/:eventId/registrations/:id/check-in
GET /api/v1/events/:eventId/registrations/export
Features
- search
- filter (status, type)
- pagination
- CSV export
8️⃣ DATABASE DESIGN
Collections
EventRSVPConfig
EventRegistration
Indexes (IMPORTANT)
eventId
status
leader.email
leader.mobile
createdAt
9️⃣ SENSITIVE DATA SECURITY 🔐
Aadhaar Handling
encrypt before storing
store last4 only
never expose full value
Compliance
- consent version stored
- data masking in responses
- audit logs for export
🔟 CUSTOM QUESTIONS SYSTEM
Supported Types
short text
long text
select
multi-select
number
file upload
url
Validation
- required questions enforced
- type-safe answers
1️⃣1️⃣ EVENT INTEGRATION
System connects with:
Event system
Community system
Member system
Example
- approved RSVP → create Member
1️⃣2️⃣ AUDIT LOGGING
Track
registration_created
status_changed
approved/rejected
export_downloaded
checkin_done
1️⃣3️⃣ ANALYTICS
Metrics
total registrations
approved count
rejected count
waitlist count
check-in rate
1️⃣4️⃣ ERROR HANDLING
Format
{
"success": false,
"message": "Team size invalid"
}
1️⃣5️⃣ RATE LIMITING
1️⃣6️⃣ TESTING
Unit
- validation logic
- duplicate checks
Integration
- full RSVP flow
- admin actions
Security
1️⃣7️⃣ EDGE CASES
duplicate registration
invalid team size
expired RSVP window
capacity overflow
invalid Aadhaar
CSV export misuse
⚙️ PERFORMANCE
- indexed queries
- pagination
- async processing
🌍 ENVIRONMENT
📦 ARCHITECTURE
/controllers
/services
/models
/validators
/utils
✅ ACCEPTANCE CRITERIA
✔ RSVP submission works
✔ Solo + Team logic works
✔ Validation enforced
✔ Duplicate protection active
✔ Admin approval system works
✔ Check-in works
✔ Aadhaar securely handled
✔ Custom questions supported
✔ Export works
✔ Fully tested
🔥 FINAL SUMMARY
This system behaves like:
Devfolio / HackerEarth / Eventbrite backend
We are building a complete RSVP & registration system for events like:
Core Flow
🎯 Goals
System must be:
🧱 CORE MODULES
1️⃣ RSVP CONFIG SYSTEM
Purpose
Each event has its own configuration.
Endpoint
Features
2️⃣ REGISTRATION SYSTEM
Endpoint
Modes
Backend Flow
3️⃣ VALIDATION SYSTEM (CRITICAL)
Must Validate
Basic
Team Rules
Solo Rules
Identity
4️⃣ DUPLICATE & FRAUD PROTECTION
Prevent
Advanced
5️⃣ RSVP WINDOW & CAPACITY
Rules
Capacity Handling
6️⃣ STATUS WORKFLOW
Lifecycle
Rules
7️⃣ ADMIN SYSTEM
Endpoints
Features
8️⃣ DATABASE DESIGN
Collections
Indexes (IMPORTANT)
9️⃣ SENSITIVE DATA SECURITY 🔐
Aadhaar Handling
Compliance
🔟 CUSTOM QUESTIONS SYSTEM
Supported Types
Validation
1️⃣1️⃣ EVENT INTEGRATION
System connects with:
Example
1️⃣2️⃣ AUDIT LOGGING
Track
1️⃣3️⃣ ANALYTICS
Metrics
1️⃣4️⃣ ERROR HANDLING
Format
{ "success": false, "message": "Team size invalid" }1️⃣5️⃣ RATE LIMITING
1️⃣6️⃣ TESTING
Unit
Integration
Security
1️⃣7️⃣ EDGE CASES
⚙️ PERFORMANCE
🌍 ENVIRONMENT
📦 ARCHITECTURE
✅ ACCEPTANCE CRITERIA
✔ RSVP submission works
✔ Solo + Team logic works
✔ Validation enforced
✔ Duplicate protection active
✔ Admin approval system works
✔ Check-in works
✔ Aadhaar securely handled
✔ Custom questions supported
✔ Export works
✔ Fully tested
🔥 FINAL SUMMARY
This system behaves like: