Senior Backend Engineer specializing in robust enterprise architectures, high-performance APIs, and financial middleware solutions using the .NET ecosystem.

I focus on translating complex enterprise requirements into maintainable, scalable, and secure production-grade software.

• Backend: C# · .NET 8 / 9 · ASP.NET Core · Web API · Entity Framework Core · LINQ · ASP.NET MVC
• Architecture & Design: Clean Architecture · CQRS · Modular Monolith · Multi-Tenancy · Offline-First Systems
• Databases & Caching: SQL Server · Redis (Distributed Caching) · MySQL · SQLite
• Security & Integrity: HMAC Signatures · JWT · Role-Based Access Control (RBAC) · Rate Limiting
• Background Jobs & Tools: Quartz.NET · Hangfire · Serilog · Git & GitHub Actions · Postman
• Frontend & UI: Angular · TypeScript · JavaScript (ES6) · HTML5 / SCSS · Bootstrap · Tailwind CSS

Enterprise-grade commercial infrastructure management solution streamlining multi-branch POS operations, inventory tracking, and real-time storefront sales analytics.

• Engineered resilient transactional web services using Modular Monolithic and Clean Architecture.
• Implemented CQRS pattern to decouple read/write paths, improving query throughput by 40%.
• Designed and delivered Offline-First architecture ensuring 100% store uptime during connectivity drops.
• Integrated distributed Redis Caching for active sessions, reducing primary database load by 30%.

Secure B2B financial compliance gateway automating legal invoice & receipt validation with the Egyptian Tax Authority portal.

• Built resilient API integration handlers synchronizing high-frequency sales data from external ERPs and platforms (Shopify, Foodics, Odoo).
• Automated batch data reconciliation pipelines using scheduled Quartz.NET background jobs.
• Hardened integration security with custom cryptographic HMAC signatures and tenant-based rate limiting.
• Enforced strict Multi-Tenant isolation guaranteeing client data privacy.

Multi-tenant SaaS platform tailored for accounting firms to manage corporate taxation lifecycles, payroll reporting, and historical audits.

• Automated government portal record retrieval, accelerating accountant reporting workflows.
• Refactored database schemas and indexing strategies, accelerating heavy financial report generation by 35%.
• Enforced strict Role-Based Access Control (RBAC) to secure multi-tenant endpoints and confidential client ledgers.

• Distributed Systems: Designing resilient service boundaries, fault tolerance, and eventual consistency.
• Event-Driven Architecture: High-throughput asynchronous messaging and event sourcing patterns.

• 🌐 Interactive Portfolio: tonyisaacg.github.io
• 💼 LinkedIn: linkedin.com/in/tony-isaac
• 💻 GitHub: @tonyisaacG
• 🏆 HackerRank: profile/antonyisaacgayed
• 📧 Direct Email: antonyisaacgayed@gmail.com