Hamoon Sheykh Hasani

- Leading the full architectural redesign of a legacy traffic enforcement platform into a modern multi-tenant SaaS system — owning system architecture, database design, REST API layer, and background processing built on Clean Architecture and CQRS. - Built payment reconciliation infrastructure across multiple payment processors — implementing read-only adapter abstraction, cursor-based windowing, and idempotency via filtered unique indexes to ensure reliable, accurate reconciliation at scale. - Designed a hybrid multi-tenant architecture with per-tenant SQL Server database isolation and a shared Directory database — eliminating cross-tenant data leakage risk and enabling secure, configurable access across multiple enterprise clients via fine-grained RBAC. - Built background processing systems including 7 Quartz jobs (sensor ingestion, traffic aggregation, payment reconciliation, SNMP polling) and real-time SignalR push for job status and dashboards. - Integrate AI-assisted development tools (Claude Code, Cursor) into daily engineering workflow — accelerating delivery across a 4-service greenfield codebase through LLM-driven code generation, architectural review, and targeted refactoring. - Tuned SQL Server query execution plans, redesigned indexing strategies, and restructured EF Core data access patterns to reduce query latency on high-volume analytical and reporting workloads across 3+ enterprise client databases.

- Independently architected and delivered multiple greenfield .NET systems — including eCommerce platforms, reporting tools, and internal automation systems — making all technical design decisions as sole developer using C#, ASP.NET Core, and SQL Server. - Designed and optimized REST APIs and SQL Server schemas for performance and scalability across business-critical workflows, including high-traffic public-facing platforms. - Delivered ghestane.com end-to-end as sole developer, then trained and onboarded the sales and SEO team on platform operations post-launch. - Worked directly with business stakeholders to translate requirements into technical architecture, owning delivery from design through deployment.

- Designed and developed an Internet Payment Gateway (IPG) and QR-based payment system using ASP.NET Web API and RabbitMQ for high-throughput asynchronous processing — handling 10,000+ daily transactions across physical and online merchant networks. - Built and maintained Windows Services for real-time receipt printing across merchant point-of-sale systems, ensuring reliable performance under continuous operation. - Architected SQL Server databases using Entity Framework Core (Code First), optimizing schema design for payment processing workflows supporting both physical and online transactions — with strong emphasis on transactional integrity and data consistency. - Developed high-performance REST APIs for credit management, BNPL (Buy Now Pay Later), and loan management systems.

• Independently designed and developed an internal project management web application using ASP.NET MVC and SQL Server, rebuilding a legacy system to address structural issues and meet updated business requirements. • Maintained and debugged the existing project management system, improving operational efficiency and system stability.