MS

Mostafa Samir

Marketplace Systems Architect

BackendFreelanceCompleted

Market API

RESTful API for marketplace operations with MongoDB backend, comprehensive Swagger documentation, and real-time data management.

Client
Erra Soft
Freelance engagement
Runtime
ASP.NET Core
Layered service architecture
Store
MongoDB
Document-oriented catalog
Contract
Swagger / OpenAPI
Generated from code
Market API showcase

Project Overview

A documented REST API for marketplace operations.

Market API is the backend for marketplace operations, built on ASP.NET Core with MongoDB and a full Swagger surface.

Document storage suited a catalog whose shape differs per vendor category, and the OpenAPI contract meant client teams could integrate without a meeting.

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 CoreMongoDBSwaggerRESTful API
Engineering Notes
  • ASP.NET Core hosting the API surface, with layered services, dependency injection and configuration-driven environments.
  • MongoDB for document-shaped data, letting product and catalog records evolve without rigid migrations.
  • 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 + MongoDB + Swagger + RESTful API stack for this project.
  • Translated design intent into a responsive, accessible interface across breakpoints.
  • Modelled and tuned the MongoDB 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 Erra Soft, 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, MongoDB, Swagger, RESTful API, shipping vertical slices โ€” data, logic and UI together โ€” 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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