Designed, built, and maintained backend services and APIs for a national-scale platform processing millions of records daily, using Kafka event streaming, ScyllaDB, and Quarkus/GraalVM — directly analogous to high-throughput cloud-native backend systems handling large request volumes. Defined and enforced backend technical standards across engineering teams: OpenAPI/Swagger contracts, secure coding guidelines, and Docker/Kubernetes deployment pipelines. Built Python-based data transformation and rule-engine services with a REST API for hot-reload configuration, plus Redis-backed caching for zero-downtime dynamic control. Managed infrastructure as code with Terraform and containerized workloads on Kubernetes across on-premises and hybrid environments, supporting scalability and reliability goals. Led code reviews and mentored engineers on clean, maintainable, and testable backend code, plus architecture decision records (ADRs).

Built high-performance backend microservices in Spring Boot and Kafka for distributed, high-availability systems, exposing REST APIs consumed by Angular front-end modules — working closely with front-end developers to integrate user-facing features. Enforced Clean Code, SOLID principles, and design patterns through code reviews; defined testing strategy (unit, integration, contract) and production-readiness standards. Resolved critical incidents with root-cause analysis and postmortems, improving system performance and reliability.

Led migration from a monolithic legacy system to Java Spring microservices and RESTful APIs for a national regulatory platform; defined backend technical standards and continuous delivery practices. Delivered advanced Oracle SQL optimization — schema design, indexing, and query tuning — for high-volume regulatory reporting; coordinated with legal, compliance, and IT stakeholders.

Designed and delivered microservices-based tax systems (Java Spring Boot / Hibernate / PostgreSQL) processing millions of taxpayer records; built RESTful APIs secured with OAuth 2.0/JWT. Developed complementary .NET Core web services for cross-platform integration and interoperability within the national tax platform, plus Angular-based administrative interfaces for tax officers. Built batch ETL pipelines with Spring Batch for large-scale data processing; automated test suites with JUnit/Mockito (TDD) achieving high code coverage. Acted as Scrum Master, driving continuous delivery across cross-functional teams and shipping reliably on schedule.

Sole backend technical lead for SINA, a mission-critical institutional platform — full ownership of architecture, database design (PostgreSQL), MVC modernization, and delivery.

Developed enterprise backend applications in C# .NET and Java with multi-layer architecture; managed QA and regression testing to ensure data integrity for high-responsibility regulatory systems.

Built payment integration APIs (Spring, Apache CXF, Quartz) with real-time transaction processing and full audit traceability for security and compliance — the Java foundation this career has built on for the 16 years since.

Built payment integration APIs (Spring, Apache CXF, Quartz) with real-time transaction processing and full audit traceability for security and compliance.