Multi-layer zero-trust authentication with OAuth2, OIDC, and MFA support across global infrastructure

Designed and implemented a comprehensive authentication system that serves as the foundation for enterprise-scale security. Features include multi-factor authentication, session management, and compliance with OAuth2 and OIDC standards.

Real-time multi-channel notification service supporting email, SMS, push, and in-app messaging

Built a scalable event-driven platform for delivering notifications across multiple channels simultaneously. Implements intelligent routing, retry logic, and comprehensive delivery tracking.

High-performance API gateway with rate limiting, request validation, and threat detection

Enterprise-grade API gateway providing centralized security, authentication, and request routing. Features include real-time threat detection, DDoS protection, and comprehensive API analytics.

PCI-DSS compliant payment gateway supporting multiple payment providers and currencies

Engineered a secure payment processing system with support for multiple payment methods, currencies, and providers. Includes fraud detection, PCI compliance, and real-time reconciliation.

Complete migration from monolithic to microservices with domain-driven design principles

Led comprehensive architecture transformation, decomposing monolithic application into independent microservices. Implemented service mesh, inter-service communication, and distributed tracing.

Distributed stream processing with sub-second latency for analytics and machine learning

Built high-throughput data streaming infrastructure for real-time analytics and ML pipelines. Features include complex event processing, windowing operations, and stream joining.

Multi-cloud infrastructure platform supporting AWS, Azure, and Google Cloud deployment

Engineered cloud-agnostic infrastructure layer enabling seamless deployment across multiple cloud providers. Includes automated scaling, disaster recovery, and cost optimization.

Multi-tier caching strategy with Redis, Memcached, and application-level caching

Optimized system performance through intelligent caching layers. Implemented cache invalidation strategies, distributed cache coordination, and cache warming techniques.

Complete event sourcing and CQRS pattern implementation for complex domain logic

Implemented advanced architectural patterns for managing complex business logic with complete audit trails. Enables temporal queries, event replay, and comprehensive system history.