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Two-way sync · Conflict resolution

CRM Synchronization Middleware

Custom middleware that keeps two CRMs and a data warehouse in perfect sync — without duplicate records or lost updates.

−96%

Duplicate records

< 2s

Sync latency

10k+/mo

Records synced

0

Data disputes

The problem

Two teams, two CRMs, one truth — and it didn't exist. Duplicates, overwritten fields, and reps arguing about whose data was right.

What I built

A middleware layer with a canonical schema, field-level conflict resolution (last-write-wins with pinned fields), idempotency keys and a full replay log. Anything that fails is retried and visible — nothing silently disappears.

Architecture

4 stages
  1. 1

    Canonical contact/deal schema + field mapping registry

  2. 2

    Bi-directional webhooks with idempotency keys

  3. 3

    Conflict resolver (pinned fields + timestamps)

  4. 4

    Replay log + admin console for failed events

Stack

Node.js Express MySQL Webhooks HubSpot

Next system

Marketing Attribution Dashboard

Got a process like this eating your team's week? Let's kill it.