Vendor Marketplace Playbook: Onboarding to Payouts

Overview

Building a marketplace means juggling vendor onboarding, inventory management, order fulfillment, and financial reconciliation. Here's how we structured TrendzMart to handle all of this without turning into an ERP monolith.

Step 1: Vendor Onboarding Flow

1. Registration: Email + basic business info
2. Verification: KYC checks (automated via API)

3. Catalog Setup: CSV import or manual entry
4. Payout Configuration: Bank details + tax info
5. Go Live: Admin approval triggers activation

Step 2: Inventory Sync

We use webhooks to keep vendor catalogs in sync:

• Vendor updates product → webhook fires
• Our system validates and updates master catalog
• Stock levels propagate to storefront
• Low stock alerts sent to vendors

Step 3: Order Management

Orders flow through a state machine:

Pending → Confirmed → Processing → Shipped → Delivered

Each state transition triggers notifications and updates.

Step 4: Automated Payouts

At month-end, we:

1. Calculate vendor earnings (total - fees - refunds)
2. Generate payout statements
3. Process payments via Stripe Connect
4. Email receipts and tax documents

Key Decisions

• Single source of truth: Master catalog, not vendor systems
• Async processing: Background jobs handle heavy work
• Audit trails: Every action logged for reconciliation

This playbook scales from 10 vendors to 10,000 with minimal changes.