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Lead Full-Stack Engineer & Architect | SASO (via iSoft) | 2021 - 2024

//Context & Scale

The Saudi Standards, Metrology and Quality Organization (SASO, contracted via iSoft) oversees all statutory vehicle technical safety and commercial modification inspections across Saudi Arabia. Nationwide testing centers operated on strict 15-minute appointment windows. Three independent client channels (public citizens, internal ministry back-office desks, and third-party mobile applications) concurrently contested the same real-time slot inventory, causing appointment collisions, orphaned slot locks from abandoned sessions, and heavy database lock contention during morning rush hours. Direct production access was restricted by federal security protocols. Retained as Lead Full-Stack Engineer and Architect over a three-year multi-phase roadmap (2021-2024) to design the core architecture, resolve concurrency bottlenecks, and execute a headless React frontend migration.

//Architectural Decisions

  • ->Distributed State Locking & TTL Recycling: Engineered a two-phase reservation protocol that held slots temporarily during booking checkout, backed by an automated 5-minute inactivity TTL window that recycled uncommitted reservations back to the national availability pool, preventing inventory lockups.
  • ->Hybrid Data Architecture (3NF & Star Schema): Enforced strict Third Normal Form (3NF) relational structures for transactional booking, vehicle registration, and ownership records to preserve ACID compliance, alongside denormalized Star Schema lookup tables for read-heavy availability calendars to accelerate complex date-range queries.
  • ->Decoupled Headless Architecture: Built versioned REST API contracts on Drupal 8/9 powering an independent React single-page application, isolating user interface iteration cycles from core booking state machines while serving mobile and ministry consumers identically.
  • ->Proxy Delegation Authorization: Engineered an authorization framework allowing registered vehicle owners to legally delegate inspection appointments to third-party drivers while maintaining statutory compliance and immutable audit logs.

//Engineering Execution

  • ->Concurrency Control & Transaction Isolation: Applied row-level locking semantics and transaction isolation levels in MySQL to eliminate race conditions between simultaneous web, mobile, and administrative booking attempts.
  • ->Synthetic Load Testing & Simulation: Authored synthetic concurrency test suites simulating thousands of simultaneous multi-channel booking requests in pre-production staging to validate locking resilience without direct production access.
  • ->OpenAPI Integration Specifications: Authored formal OpenAPI contracts governing payloads between the headless React UI, backend microservices, and mobile application clients.

//Measurable Impact

  • ->Zero Concurrency Collisions: Completely eliminated race condition double-bookings across all three client channels nationwide.
  • ->100% Capacity Recovery: Deterministic 5-minute TTL recycling restored every abandoned reservation window back into the active national pool, eliminating wasted inspection bay capacity.
  • ->Sub-Second Availability Lookups: Star Schema calendar denormalization reduced availability search latency to sub-second speeds under high national concurrent load.
  • ->Zero Regression Releases: Staged synthetic simulations and decoupled APIs ensured zero regression failures across three years of production cutovers.