Started as a hobby exploring business automation for trading card resale. Turned into a platform that runs a profitable business on a few hours a week. I handle sorting intake and shipping. The platform handles everything else.
738+
Sales Tracked
56
Active Listings
~3hrs
Weekly Effort
Profitable
Business Status
The Challenge
TCG Businesses Don't Scale Manually
Trading card businesses deal with thousands of unique products, each with fluctuating market prices across multiple platforms. The sheer quantity makes manual inventory tracking, pricing analysis, and market monitoring unsustainable.
Inventory Chaos
Thousands of individual cards across eBay and CardMarket. No unified view. Stock checks meant switching between tabs and cross-referencing spreadsheets.
Market Blindness
Price differences between platforms create arbitrage opportunities, but spotting them manually across thousands of products is impossible.
Time Sink
Listing, relisting, price adjustments, order reconciliation, profit tracking. The admin overhead was consuming more time than the actual business.
The Platform
Automate the Pain Points
Each system was designed to address a specific operational bottleneck. The goal: reduce my role to what only a human can do: sorting intake and shipping orders.
eBay Integration
Full Trading API + Finances API integration with OAuth 2.0 digital signatures (ED25519). Automated sales sync, listing management, and financial reconciliation.
CardMarket Automation
No public API exists, so I built automated Selenium/Playwright scraping with anti-detection, proxy rotation, and order processing.
Cross-Marketplace Analytics
Unified inventory across platforms. Arbitrage detection surfaces price differences automatically. Per-product profit/loss tracking across all channels.
Resilience at Scale
Retry with exponential backoff, circuit breakers, graceful degradation. The platform runs unattended, so it needs to handle failures without human intervention.
The Result
A Business That Runs Itself
The platform proved the model works. The business is profitable, and my weekly involvement is down to a few hours, sorting incoming stock and shipping fulfilled orders. Everything else (inventory tracking, price monitoring, sales reconciliation, analytics) is automated.