Build your own Amazon.

# Build an original app inspired by Amazon

You are an experienced product designer and full-stack engineer. Build a working, polished MVP from the brief below. Implement the core journeys end to end; a static mockup is not sufficient. Inspect the current environment, make sensible implementation decisions, and get started. Ask a question only if a missing answer genuinely blocks implementation.

Starting platform: Web. Explicit customized Product & audience and Tech stack requirements take precedence over this starting target.

## Product & audience
Build an original multi-seller product marketplace called Marketlane, inspired by Amazon retail workflows. Buyers compare products and seller offers, add items to a cart, and place a test order. Sellers manage only their own offers and fulfillment. Begin with a small original catalog, one currency, and no real money movement.

## Design
Use an original searchable catalog, category filters, product details, offer selection, cart, and buyer/seller dashboards. Make seller identity, stock, shipping assumptions, and order status visible. Keep pricing and availability readable on mobile rather than reproducing Amazon branding or page layouts.

## Features
1. Catalog and offers: separate shared product descriptions from seller-owned offers, variants, prices, and stock. Provide authorized seller editing and administrator review with only original or licensed images.

2. Discovery: search product names and attributes, filter by category and availability, sort by actual prices, and save a wishlist. Offer selection must identify the chosen seller before adding to the cart.

3. Cart and checkout: calculate prices on the server, validate stock, reserve inventory atomically, and create an idempotent no-payment or sandbox order. Reject changed prices with a visible review step.

4. Seller fulfillment: split a buyer order into seller suborders, support processing/shipped/cancelled states, and release inventory on permitted cancellation. Sellers cannot read another seller’s customer/order data.

5. Buyer records and reviews: show durable order history and line-item snapshots, support an explicit return-request workflow, and allow moderated reviews only for fulfilled purchases in the pilot.

## Tech stack
Use TypeScript for the storefront, Python/Django for the API, and PostgreSQL for stock, orders, and seller permissions. Use database transactions for reservations and an outbox worker for notifications. If payment is added later, start with provider test mode and signed, idempotent server webhooks.

## Data & behavior
User; Seller; Product; Variant; Offer {sellerId, priceMinor, stock}; Cart; CartLine; StockReservation; Order; SellerOrder; OrderLine {offerSnapshot}; FulfillmentEvent; ReturnRequest; Review. Store amounts in integer minor units and retain order snapshots when catalog records change.

Acceptance checks and scope:
Test two buyers checking out the last unit, a seller changing a price, repeated checkout, mixed-seller orders, cancellation stock release, and unauthorized seller access. Exclude Amazon catalog scraping, Prime logistics, live seller payouts, global taxes, and recommendation ML. The result is a marketplace pilot rather than a full retail infrastructure.

## Originality and assets
The named product is a reference for general workflows only. Use an original product name, visual identity, wording, layout, and assets. Do not copy proprietary code, branded logos, distinctive screens, private APIs, paid templates, or protected media. Use original or appropriately licensed sample data and assets. Build from this brief rather than scraping the reference service. Do not imply affiliation with the referenced company.

## Implementation quality
- Make every visible control work, with clear loading, success, empty, validation, and failure states. Remove controls for unimplemented features.
- Support the target platform and responsive or resizable layouts where appropriate. Use platform-appropriate accessibility semantics, labels, keyboard operation, visible focus, sufficient contrast, and reduced-motion preferences. Provide alternatives for drag-only interactions.
- Validate inputs at the relevant boundary. Treat imported or user-generated content as untrusted; render it safely. Confirm destructive actions or offer undo.
- Keep state changes reliable across navigation and reloads. Never silently lose edits. Handle persistence and network errors with an actionable message.
- Keep the scope realistic. Prioritize the complete primary journey. If a custom Features section differs from the baseline, update the data model, design, and acceptance checks to match it; explicit custom requirements take precedence over baseline assumptions.
- Provide realistic original sample content and a useful empty state. Keep sample data clearly separate from user-created data.

## Delivery and verification
1. Inspect the repository and outline the implementation in a few sentences.
2. Implement the app and connect its actual data flow. Continue until the primary journey works.
3. Run appropriate checks and test the acceptance cases above on the target platform. Verify responsive layouts and keyboard navigation when browser tools are available. For native projects, build with the available SDK and test an emulator or device when possible; report any missing native verification honestly. For games, verify the rules and gameplay loop, not only the menus.
4. Fix observed failures, then provide the runnable result, setup/run instructions, a brief explanation of what is implemented, and any specific configuration or verification limits.

This is a focused MVP. Do not add billing, AI services, or unrelated features unless explicitly requested in the brief. Start building now.