Mohammed Mostafa Mohammed Ahmed

Built and maintained a multi-tenant SaaS platform for managing Egyptian tutoring centers, covering student management, attendance, per-session payments, scheduling, teacher payouts, and financial reporting. Architected secure per-center data isolation and two-tier role-based access control (section- and action-level permissions) across 40+ protected API endpoints. Developed a financial engine that supports per-session, partial/credit payments, automated teacher payout settlement, and daily cash-drawer reconciliation, backed by 370+ automated tests. Created a super-admin console on a subdomain with subscription/plan management, read-only impersonation, and an append-only audit log. Improved performance by reducing DB query latency from ~145ms to single digits through eliminating N+1 patterns and adding a caching layer while resolving a cross-region bottleneck.

Built a full-stack e-learning platform where students can browse courses, enroll, watch protected video lessons, access PDF materials, and track learning progress. Implemented an admin dashboard for courses, pricing, and content management. Integrated payment gateway processing across 2+ supported methods and added impression/click tracking for served ads.

Developed and maintained 2+ production web applications using Node.js, React.js, and Express.js for a growing user base with 99%+ uptime. Improved API response time by ~30% by identifying and resolving performance bottlenecks in OpenAI API integration pipelines. Collaborated with a cross-functional team to ship features within 1–3 week sprint cycles. Reduced bug backlog by 40% via systematic troubleshooting and improved error handling across multiple platform modules. Contributed UI/UX improvements that enhanced user task completion across several key screens.