An order pipeline that surfaces the margin data no-code tools can't
Pulls raw eBay Fulfillment API data into a structured Google Sheet — net profit per order, ad fees, buyer repeat status, fulfillment deadlines, refund flags — with custom business logic and one-time ownership instead of a monthly subscription.
The problem
A marketplace seller can see revenue easily. Margin is the hard part, and margin is the number that decides what to reorder and what to stop selling.
The data exists, but it sits deep inside the eBay Fulfillment API payload: per-order fee breakdowns, promoted-listing ad fees, refunds, buyer history. Off-the-shelf connectors surface only the flat summary fields at the top of an order, so the numbers that actually determine profit never make it out.
The alternative is a SaaS dashboard — another monthly subscription, someone else's schema, and no way to encode business logic specific to the operation.
What I built
A pipeline that reads raw order payloads from the eBay Fulfillment API, applies the seller's own margin logic, and writes a structured per-order sheet.
- 01
Straight to the raw API
Authenticates against the eBay Fulfillment API and pulls complete order payloads, not the reduced view a connector exposes. The whole system rests on this decision: everything downstream is possible only because the raw response is available.
- 02
Custom margin logic
Parses line items, fee breakdowns, and promoted-listing ad fees to compute net profit per order, rather than treating gross sale price as revenue.
- 03
The fields that drive decisions
Derives buyer repeat status, fulfillment deadlines, and refund flags per order — signals latent in the payload that have to be computed, not read off a field.
- 04
Google Sheets as the interface
Output is written to a structured Google Sheet: no new tool to learn, sortable and filterable on day one, and easy to extend with the seller's own columns.
- 05
One-time ownership
Delivered as code the owner keeps and runs, deliberately not as a subscription. The trade-off stated plainly: no vendor support desk, in exchange for no recurring fee and full control of the logic.
The outcome
Per-order margin visibility that the no-code path structurally cannot reach — net profit after ad fees, repeat-buyer status, fulfillment deadlines, and refund flags, all in one sheet, per order.
The system runs live. Because it is owned outright rather than rented, cost is fixed at build time and the business logic can change whenever the operation changes. That is the point of building it instead of subscribing to it.
Want to see how this was built?
Happy to walk through the system and what a similar build would take.