● The Problem
Legacy payment gateway platform required modernization, new merchant management capabilities, comprehensive reporting, and performance improvements to handle increasing transaction volumes while maintaining system reliability.
● The Solution
Developed merchant management module, implemented campaign and commission systems, built comprehensive reporting infrastructure, optimized database queries and concurrency handling, enhanced security, and migrated to modern frameworks while maintaining backward compatibility.
● Project Impact
Delivered production-ready payment gateway platform with merchant self-service capabilities, automated campaign management, comprehensive reporting, improved transaction processing performance, and enhanced security measures supporting business growth.
Payment Gateway Platform Customization & Enhancement
TL;DR: Led comprehensive customization and enhancement of enterprise payment gateway platform over 4.5 years, delivering merchant management module, campaign system, reporting infrastructure, performance optimizations, and security enhancements supporting high-volume transaction processing.
The Challenge
The payment gateway platform was a legacy system requiring significant modernization to support evolving business needs. The platform needed to handle increasing transaction volumes while providing merchants with self-service capabilities, automated campaign management, and comprehensive reporting. Key challenges included:
- Legacy Architecture: System built on older Java versions (JDK 1.5) with limited scalability
- Manual Operations: Merchant management and campaign operations required manual intervention
- Limited Reporting: Insufficient reporting capabilities for merchants and administrators
- Performance Bottlenecks: Database queries and concurrent transaction processing needed optimization
- Security Gaps: Required enhanced authentication, authorization, and access control mechanisms
- Integration Complexity: Multiple payment providers and services needed seamless integration
The platform needed to maintain high availability, handle concurrent transactions safely, and provide real-time insights while supporting business growth.
The Solution
Architecture Design
Architectural Decisions
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Modular Architecture: Separated core logic from application modules to enable independent deployment and maintenance of merchant management, online gateway, and customer care modules
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Service-Oriented Design: Implemented service layer abstraction for charging, wallet, campaign, and commission services to ensure separation of concerns and testability
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Database Optimization Strategy: Implemented database partitioning, indexing strategies, and query optimization to handle high-volume transaction processing efficiently
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Concurrency Management: Implemented synchronized locking mechanisms and transaction-level locking to prevent race conditions in balance updates and critical operations
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Backward Compatibility: Maintained compatibility with existing JDK 1.5 modules while migrating newer components to JDK 1.8, enabling gradual modernization
Key Contributions & Problem Solutions
Merchant & Transaction Features
The Problem: Manual operations, limited flexibility in campaigns/commissions, and rectifying failed transactions caused significant overhead.
- Merchant Management: Built self-service capability with wallet operations and role-based access.
- Result: Reduced support tickets by a significant margin.
- Campaign System: Automated campaign lifecycle and bonus payments.
- Result: Reduced setup time from days to minutes.
- Commission Engine: Implemented flexible, rate-based commission schemes.
- Result: Automated calculation accuracy and financial reporting.
- Reporting: Developed multi-level reporting with CSV exports and pagination.
- Result: Actionable insights for business and merchants.
- Rectification: Automated flows for failed transaction recovery and reversals.
- Result: Improved transaction success rates and financial accuracy.
Tech Stack
Impact & Results
Business Impact
- Operational Efficiency: Self-service capabilities slashed support overhead, allowing merchants to operate 24/7 independently.
- Revenue Growth: Automated campaign and commission systems enabled rapid rollout of marketing strategies, directly driving transaction volume.
- Data-Driven Decisions: Transitioned from limited visibility to comprehensive, real-time insights for both the business and merchants.
Technical Efficiency
- Concurrency Safety: Robust locking mechanisms completely eliminated race conditions, ensuring 100% financial accuracy under high load.
- Scalable Architecture: Modular service design and database partitioning decoupled components, allowing independent scaling and maintenance.
- Modernization: Successfully bridged legacy Java 1.5 systems with modern standards, extending platform life without full rewrites.
Operational Excellence
- Proactive Reliability: Shifted from reactive fire-fighting to proactive monitoring with health checkers and automated low-balance alerts.
- Audit & Compliance: Granular RBAC and comprehensive audit logging ensured full traceability of all sensitive financial operations.
Key Learnings
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Legacy System Modernization: Successfully modernized legacy systems while maintaining backward compatibility requires careful planning and incremental approach
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Performance at Scale: Database optimization, caching strategies, and concurrency control are critical for high-volume transaction processing systems
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Security First: Implementing security measures early in the development process is more effective than retrofitting security later
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Comprehensive Testing: Building simulators and testing infrastructure enables faster development cycles and reduces production issues
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Documentation Value: Maintaining comprehensive documentation significantly improves team productivity and system maintainability
My Role
Senior Software Engineer
hSenid Mobile Solutions
Technologies Used
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