WB-SMP — Wildberries Seller Management Platform

Challenge

Wildberries sellers face 34.5–38% commission rates with limited visibility into true unit economics. They need:

• Real-time margin per SKU after all fees
• Automated advertising bid optimization
• Inventory forecasting to prevent stockouts
• Competitive intelligence

Build a unified command center integrating 262 API endpoints across 14 Wildberries hosts.

Solution Architecture

Platform Overview

Modular monolith with 9 bounded contexts serving growing sellers (10–50 SKUs, 100K–1M RUB/month revenue).

┌─────────────────────────────────────────────────────────────────┐
│                       React SPA (Frontend)                       │
└────────────────────────┬────────────────────────────────────────┘
                         │ HTTPS
                         ▼
┌─────────────────────────────────────────────────────────────────┐
│                    Nginx Ingress (k3s)                           │
└────────────────────────┬────────────────────────────────────────┘
                         │
        ┌────────────────┼────────────────┐
        ▼                ▼                ▼
┌──────────────┐ ┌──────────────┐ ┌──────────────┐
│  FastAPI App │ │ Celery Beat  │ │ Celery Tasks │
│ (8 routes)   │ │ Scheduler    │ │ (workers)    │
└──────┬───────┘ └──────┬───────┘ └──────┬───────┘
       │                │                 │
       ├────────────────┼─────────────────┤
       │                │                 │
       ▼                ▼                 ▼
┌─────────────────────────────────────────────────────┐
│         Bounded Contexts (9 modules)                │
│  Auth | Catalog | Pricing | Fulfillment |          │
│  Advertising | Analytics | Intelligence |          │
│  Inventory | Support                               │
└─────────────────────────────────────────────────────┘
       │
       ├── PostgreSQL + TimescaleDB (time-series)
       ├── Redis Sentinel (caching)
       └── Vault HSM (API key management)

Core Features

1. Unit Economics Dashboard Real-time margin visibility per SKU:

Revenue:     100,000 RUB
├── WB Commission:    -35,000 (35%)
├── Logistics:         -8,000
├── Storage:           -2,500
├── Advertising:       -5,000
├── Returns:           -3,000
└── Net Margin:       46,500 RUB (46.5%)

2. Auto-Bid Optimizer Automated advertising bid management targeting ROAS:

• Hourly bid adjustments based on conversion data
• A/B testing for keyword bids
• Budget pacing to prevent overspend
• Reduces manual bid management by ~3 hrs/week

3. Inventory Forecasting 14-day horizon predictions:

• Stockout alerts before Amazon-style penalties
• Overstock warnings for slow-moving SKUs
• Reorder point calculations
• FBS/FBW split recommendations

4. Competitive Intelligence Public API monitoring:

• Competitor price tracking
• Category trend analysis
• Search ranking intelligence
• Card quality scoring

Tech Stack

Wildberries API Integration

14 API Hosts Integrated

Content API:     catalog, media, cards
Prices API:      pricing, discounts
Marketplace API: orders, supplies, returns
Statistics API:  sales, stocks, income
Advert API:      campaigns, bids, budgets
Feedbacks API:   reviews, questions
Recommendations: category rankings

Rate Limit Management

• Token bucket per API host
• Automatic backoff on 429s
• Priority queue for critical operations
• Webhook handlers for real-time events

Security Architecture

API Key Management

Vault KV v2:
└── secret/wb-smp/
    ├── sellers/{id}/api_token  (encrypted)
    ├── sellers/{id}/refresh_token
    └── rotation_schedule

• Shamir unseal (3-of-5 threshold)
• 90-day automatic rotation
• Audit logging for all access
• Zero plaintext storage

Compliance (152-FZ)

Russian data protection law alignment:

• Data localization (Russia-hosted)
• Consent management
• Data retention policies
• Audit trail for personal data access

Results & Metrics

Documentation Coverage

Requirements:
├── Business: BRD, market analysis, glossary
├── Product: PRD, user personas, flows
├── Functional: 8 FSDs (analytics, ads, inventory, etc.)
├── Technical: SRS (6 docs), ADRs (10+)
├── Quality: Test strategy, SLO/SLA, observability
└── Security: Threat model, compliance, token mgmt

Target Outcomes

1. Time Savings: 3+ hours/week on bid management
2. Margin Visibility: Real-time unit economics
3. Stockout Prevention: 14-day forecasting
4. Competitive Edge: Public API intelligence

Architecture Decisions

• Modular monolith over microservices: Single deployment, easier debugging, DDD boundaries
• TimescaleDB over ClickHouse: Better PostgreSQL integration, sufficient scale
• Vault HSM over AWS KMS: Self-hosted, 152-FZ compliant, no cloud dependency
• Feature-slice frontend: Scalable React architecture with code splitting