FARSIN SIDDIK .

Senior Software Engineer

Tag Systems UK

- Architected and developed high-performance card payment processing APIs supporting 1M+ cardholders in a PCI-DSS compliant environment, serving enterprise clients including HSBC and HyperJar.

- Re-engineered backend architecture, increasing transaction throughput from ~20 TPS to 150–200 TPS and enhancing system concurrency to reliably handle 1500–2000+ concurrent requests under stress and 10k requests within 1.5 minutes and 100k requests within 9 minutes without horizontal scaling or failures, achieved on a single 8-CPU, 32-GB instance.

- Designed reactive, non‑blocking microservices using Spring WebFlux and asynchronous event‑driven processing.

- Applied advanced multithreading and concurrency concepts (event loop model, async messaging, parallel processing) for high TPS transaction systems.

- Optimized payment routing and gateway transaction flows to consistently meet strict sub‑3‑second SLA windows.

- Applied SOLID principles and clean architecture to improve maintainability, extensibility, and testability of microservices.

- Led system design decisions, reviewed PRs, optimized database queries, and mentored engineers in performance‑first backend engineering.

- Collaborated closely with Product and QA teams to deliver high-quality, business-aligned software solutions, while actively participating in Agile ceremonies including sprint planning, retrospectives, and daily stand-ups.

Software Engineer

Accubits Technologies

- Led backend engineering for fintech wallet and card processing platform handling secure transaction workflows.

- Designed and implemented scalable RESTful microservices using Java 11 and Spring Boot.

- Implemented asynchronous, event‑driven architecture using RabbitMQ for transaction processing and audit pipelines.

- Used multithreading and concurrency techniques for parallel transaction execution and performance optimization.

- Improved backend reliability and quality achieving 90%+ unit and integration test coverage.

- Collaborated on payment system architecture, database schema design, and secure API development.

- Managed end-to-end code review and merge/pull request workflows, coordinated QA/UAT/PROD release readiness, and administered JIRA backlog, prioritizing tasks based on complexity, dependencies, and delivery timelines.

- Guided junior developers in applying SOLID principles, performance optimization, and effective debugging practices.

- Recognized as the team’s “Problem Solver” for consistently diagnosing and resolving complex technical issues.

Software Engineer III

UST

- Migrated legacy monolith banking modules to scalable microservices using Java 8 and Spring Boot.

- Developed high‑volume transaction processing modules and optimized SQL/PLSQL queries for performance.

- Worked on concurrent backend processing, thread management, and performance tuning in enterprise banking systems.

- Designed database scripts, tables, and optimized query execution for transactional workloads.

- Contributed to large-scale enterprise banking/fintech platforms for global clients including Barclays, Experian, and O2, with a focus on system modernization and compliance-driven development.

Software Engineer

Ospyn Technologies

- Owned the development of critical modules in a large-scale web application used by over 100K users.

- Built features from scratch and resolved early-stage defects in production with fast turnaround times.

- Analyzed and optimized long-running SQL queries by identifying performance bottlenecks, implementing proper indexing strategies, and rewriting queries with efficient joins and filters to improve execution time.

- Developed frontend modules using JSP, JavaScript, and jQuery integrated with backend REST services.

- Collaborated with QA and DevOps teams to streamline deployment cycles.

IT Technical Engineer

Celebrity Systems

- Managed deployment and operations of distributed digital advertising and media systems across multiple production environments at Muscat Duty Free.

- Coordinated with senior stakeholders and airport authorities to plan releases, monitor system performance, and ensure timely project delivery.

- Configured secure connectivity between geographically distributed servers, enabling reliable multi-location data communication and transaction processing.