احمد بسيوني

• Designed and deployed a containerized application architecture using Docker,
improving deployment speed by 20%.
• Implemented secure authentication and RBAC authorization using JWT,
protecting 1, 000+ user accounts.
• Optimized MongoDB queries and aggregation pipelines, reducing API response
latency by 30%.
• Integrated Stripe payment processing and Cloudinary media management
services.
• Collaborated with cross-functional teams to deliver scalable, production-ready
web applications.

Delivers production-grade web applications for paying clients while working independently alongside other commitments.
• Built a production MERN healthcare booking platform for a paying client — enabling real-time appointment management for 3+
clinic locations, handling 500+ monthly appointments with 409 Conflict race-condition prevention.
• Engineered a dynamic slot-generation engine computing availability from doctor scheduling rules (hours, breaks, session
duration) — eliminating static slot records and improving mobile Core Web Vitals by 15% (Lighthouse-measured).
• Implemented multi-role dashboards (Admin, Doctor, Patient) with permission-gated API endpoints, MIME-validated Cloudinary
storage, and automated CI/CD pipelines via GitHub Actions for zero-downtime deployments.

Contract
Worked on a multi-tenant enterprise SaaS platform serving 1, 000+ active users across KSA.
• Diagnosed critical MongoDB bottlenecks and redesigned aggregation pipelines with MongoDB Aggregation and compound
indexing — cutting P95 API response time by 28% under production load, directly improving system scalability for 1, 000+ users.
• Architected a Docker-containerized backend using Docker Compose with modular service-based architecture, standardizing
dev/production environments and reducing deployment time by 18%.
• Engineered JWT + Refresh Token Rotation with RBAC across 3 roles (Admin, Vendor, Customer), building a layered security
architecture that enforced granular API Security across 1, 000+ active accounts.
• Integrated Stripe payment processing with idempotency key handling — reducing failed payment retries and eliminating
duplicate charges — and Cloudinary for high-volume image pipelines; delivered within an Agile/Scrum team of 15 engineers.

Freelance
• Built and deployed healthcare booking platforms using MERN stack for real-world
clients.
• Designed a real-time scheduling engine handling 500+ monthly appointments
with conflict prevention logic.
• Improved Core Web Vitals and frontend performance, increasing mobile
engagement by 15%.

Completed an intensive backend development program focused on production-grade Node.js systems.
• Built 10+ backend modules — authentication, content feeds, real-time notifications — using Node.js, Express, and MongoDB
under concurrent production load, applying modular backend design and Performance Optimization practices.
• Eliminated IDOR vulnerabilities by enforcing route-level Authentication & Authorization via custom JWT middleware —
removing insecure direct object references identified during QA.
• Optimized high-frequency content-feed queries using MongoDB explain() analysis and compound indexes, directly improving
data retrieval speed under daily active user load.

Developed internal web applications and full-stack features in a professional software team.
• Built full-stack features across the entire product using React.js and Node.js/Express, applying MVC Architecture and REST API
Design principles to deliver scalable codebases serving 200+ internal users.
• Engineered 30+ reusable React components following Clean Architecture and component-based patterns, reducing UI code
duplication by 20% and shortening cross-team Code Review cycles.
• Collaborated in Agile/Scrum sprints with cross-functional teams — translating System Design requirements into RESTful APIs
with input validation and Authentication & Authorization controls.

• Completed an 11-month intensive residency focused on full-stack JavaScript
development.
• Delivered 5+ production-ready projects using clean architecture principles.
• Collaborated within a team of 5 to develop an ERP system with complex state
management using Redux Toolkit.
• Developed 25+ reusable React components to accelerate development cycles and
reduce code duplication by 20%.