From gut-feel CRM to a system that validates every campaign with statistics — in 7 weeks
We unified scattered customer, order, and messaging data onto a single CRM rail and shipped a production system that runs A/B validation on a statistical basis — all in 7 weeks.
- Client
- Company E (D2C e-commerce brand)
- Period
- Apr–Jun 2026 (7 weeks)
- Role
- Sole design, build, and operational handover of the CRM system
7 weeks
Time to production
19
Real-time event types
4 channels
Sending channels
17
Cohort condition fields
67
Zero-downtime schema migrations
The Problem
- No framework existed to diagnose the entire customer base quantitatively before running CRM
- Customer, order, and messaging data were fragmented, making it impossible to compare performance between organically acquired and influencer-driven customers
- Campaign decisions relied on the operator's intuition
Approach
- Redesigned the workflow itself into a four-stage "CRM rail": diagnose → target → execute → validate
- Built the data foundation on 19 real-time commerce-platform webhooks plus 9 overnight aggregation batches
- A/B sends use deterministic sha256 assignment and a two-proportion z-test to declare the winner
- Beyond meeting every contractual success criterion, delivered four out-of-scope areas: the diagnostic rail, customer scatter plots, webhook sync, and a GA4 + first-party tracker
Systems Built
| Module | Description |
|---|---|
| Data integration & auto-aggregation | 9 overnight batches, idempotent processing |
| Cohort management | 17 AND/OR fields, snapshots |
| Acquisition-source engine | Auto-classifies organic vs. influencer-driven customers |
| Experiment design & A/B sending | Built-in statistical testing |
| Multi-channel sending | SMS, LMS, AlimTalk, brand message — 4 channels, compliance built in |
| Tracking & evaluation | 5-tab reporting, 8-stage message-response funnel, RFM 5×5 heatmap (build a cohort straight from any cell) |
| Handover package | 30 API docs, 4 operations runbooks |
Screens
Tech Stack
Next.js 14Node.jsPostgreSQL (RDS)AWS EC2pg-bossSentryCafe24 API/WebhooksGA4
Metrics reflect system scale and delivery scope. Revenue-performance metrics will be compiled once the measurement infrastructure is live.
