E-Commerce and Marketplace Development: Plan Beyond the Storefront

An attractive storefront is only one part of selling online. Stock must be accurate, payment status must be trustworthy and the fulfilment team must know which orders are ready. A marketplace adds another layer: vendors, commissions and responsibility when something goes wrong. Define the operating model before asking a development team to estimate screens.

Choose the first commerce model

A single-seller store can launch with one catalogue and one fulfilment process. A marketplace needs vendor onboarding, listing review and rules for order allocation. Decide whether an order can include multiple vendors and who communicates with the customer. These choices affect data models, support tools and delivery scope, so they belong in discovery.

Treat payment and fulfilment as separate states

A customer returning from checkout is not, by itself, proof that a payment succeeded. The application must reconcile trusted provider events with the order record and handle duplicate or delayed notifications. Similarly, a paid order is not automatically dispatched. Map paid, packed, shipped, delivered, cancelled and refunded states with clear rules for transitions.

Verify difficult orders before launch

• A product sells out while a customer is checking out.
• A payment notification arrives more than once.
• Only part of an order can be shipped.
• A customer requests a return after delivery.
• A vendor listing is rejected or temporarily unavailable.

Worked example: a payment event arriving twice

For an illustrative store, a customer pays for an order and the payment provider sends the same successful event twice. Processing both events as separate purchases could create duplicate fulfilment records. The acceptance test should show that the application recognises the already-processed event and retains one valid order outcome.

Next, test an event that arrives after the customer closes the checkout tab. The order should reconcile from the provider event rather than depending on that browser returning. Stripe’s webhook documentation explains duplicate events and signature verification for Stripe integrations; apply the equivalent documented rules for the payment provider selected for your project.

Planning worksheet

Connect the store to the business

Identify who maintains product data, how stock synchronises and what accounting exports are needed. Launch with a manageable catalogue and rehearse support scenarios with the staff who will answer customer questions. INFACT Solutions lists an e-commerce and marketplace platform with optional vendor, loyalty and ERP/POS integrations. Use a workflow review to decide which capabilities belong in your first release and which can follow later.