[BE-43] NPS satisfaction survey automation: backend

[yusuftomilola]

Overview

There is no systematic way to measure member satisfaction. NPS (Net Promoter Score) surveys sent automatically after a completed booking provide quantifiable feedback and identify members to retain or win back.

Context

• CompleteBookingProvider: backend/src/bookings/providers/complete-booking.provider.ts — trigger survey here
• EmailModule: backend/src/email/ — deliver the NPS survey email
• @nestjs/schedule: schedule the delayed email send (2 hours after completion)

Tasks

• Create NpsSurveyResponse entity: id, userId (FK), bookingId (FK, unique — one response per booking), score (int, 0–10), comment (text, nullable), submittedAt (timestamptz), createdAt
• In CompleteBookingProvider: after booking status → COMPLETED, schedule a delayed job (via Bull, 2-hour delay) to send NPS survey email
• Email contains a link to /nps/[bookingId] with the booking ID; pre-fill context (workspace name, booking date)
• POST /nps/respond — authenticated member submits { bookingId, score, comment }; reject if already responded
• Rate limit NPS sends: do not send more than one survey to the same member within 30 days (check before queuing)
• GET /nps/summary — admin endpoint: { averageScore, promoters, passives, detractors, npsScore, totalResponses, recentComments }
  • Promoters: score 9–10; Passives: 7–8; Detractors: 0–6; NPS = (Promoters% - Detractors%)
• GET /nps/responses — paginated raw responses (admin only)

Files to Modify / Create

• New: backend/src/nps/ (module, entity, controller, service, bull processor)
• backend/src/bookings/providers/complete-booking.provider.ts
• backend/src/app.module.ts