MS

Mostafa Samir

Marketplace Systems Architect

BackendFreelanceCompleted

E-Commerce API

Full-featured e-commerce backend API with SQL Server database, Swagger documentation, and comprehensive endpoint coverage.

Client
We3ds
Freelance engagement
Runtime
ASP.NET Core
Layered service architecture
Store
SQL Server
Transactional relational data
Contract
Swagger / OpenAPI
Full endpoint coverage
E-Commerce API showcase

Project Overview

A full e-commerce backend with a stable, documented contract.

E-Commerce API covers the complete commerce backend — catalog, cart, orders, customers and auth — on ASP.NET Core with SQL Server.

Relational storage was the right call here: orders, line items and inventory are highly relational and benefit from transactional guarantees.

The Challenge

The API had to serve multiple front-end clients with different needs while remaining stable, discoverable and documented enough for another team to integrate without hand-holding.

The Approach

Clean separation between controllers, services and data access, an OpenAPI contract generated from the code, and a consistent validation and error envelope across every endpoint.

Core Features

01

RESTful endpoint surface

Resource-oriented endpoints with consistent verbs, status codes and payload shapes across the API.

02

Interactive documentation

Swagger/OpenAPI definitions kept in sync with the code so consumers can explore and test live.

03

Authentication & authorization

Token-based auth with role checks applied at the endpoint level.

04

Validation & error contract

Request validation with a single predictable error envelope instead of ad-hoc failure shapes.

05

Data access layer

Repository abstraction over the database with paging, filtering and projection support.

Architecture & Tech

Tech Stack

ASP.NET CoreSQL ServerSwaggerRESTful API
Engineering Notes
  • ASP.NET Core hosting the API surface, with layered services, dependency injection and configuration-driven environments.
  • SQL Server as the relational backbone, with parameterised access and tuned indexes.
  • Swagger/OpenAPI generated from the code so documentation cannot drift from the implementation.
  • REST conventions for resources, verbs and status codes, with predictable pagination and error shapes.

My Role & Contributions

  • Designed the API surface, data model and validation rules end to end.
  • Implemented the full ASP.NET Core + SQL Server + Swagger + RESTful API stack for this project.
  • Translated design intent into a responsive, accessible interface across breakpoints.
  • Modelled and tuned the SQL Server schema behind the feature set.
  • Handled client communication, scope decisions, delivery and handover directly.
  • Deployed and verified the production build.

Delivery Process

  1. 01

    Discovery & scoping

    Requirements gathered directly with We3ds, translated into a prioritised scope and a data model sketch before any code.

  2. 02

    Contract & schema design

    Endpoint contract, request/response shapes and database schema designed first, so clients could integrate against a stable surface early.

  3. 03

    Implementation

    Built iteratively with ASP.NET Core, SQL Server, Swagger, RESTful API, shipping vertical slices — data, logic and UI together — instead of layer by layer.

  4. 04

    Hardening & launch

    Edge cases, validation, responsive behaviour and performance passes, followed by deployment and post-launch monitoring.

Results & Outcomes

  • Shipped to production and publicly reachable at the live URL.
  • Responsive from small mobile screens through large desktop layouts.
  • Documented endpoints that other teams could integrate against without direct support.
  • Current project status: Completed.

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