JM Gerona

Account Management Offboarding (BSP Regulatory Compliance)

• Architected event-driven offboarding system processing 30 million accounts for BSP compliance, with Kafka event streaming for real-time KYC monitoring + Kubernetes CronJobs for monthly fee collection
• Created comprehensive technical artifacts: logical/physical/data flow/sequence diagrams, network diagrams, database schemas, pseudocode, performance testing specs

Spending Limits Breakdown (BSP Regulatory Compliance)

• Architected real-time aggregation system for users with up to 5 linked accounts; designed parent-child profile architecture (1 parent profile ID → multiple account IDs) enabling single-query multi-account retrieval
• Implemented caching strategy and asynchronous refund processing for real-time spending adjustments

Unlimited Limits Bug Mitigation (15M Accounts Remediation)

• Architected automated remediation fixing 15M accounts with missing spending limits records from 2019 data migration
• Designed multi-threaded batch processor with cache invalidation; implemented concurrent Kubernetes processing (3 pods + 3 cron jobs) for off-peak execution within strict time windows

ZOLOZ Migration & Offer Takeover

• Architected gradual migration strategy with traffic splitting for zero-downtime transition from on-premise to cloud-based ZOLOZ
• Designed end-to-end automated data pipeline and voucher seeding system processing 1 million eligible users monthly

• Re-architected FIS token persistence from CronJob to persistent process with internal 5-minute polling, implementing Redis-based caching for thousands of monthly card orders
• Led hands-on implementation of VISA card integration via FIS, developing RESTful APIs with PCI DSS compliant logging
• 100% hands-on coding role

• Led team maintaining internal back-office app for transaction monitoring: buy load, bills pay, QR payments, acquiring, money-in/out
• Performed code reviews enforcing Spring Boot best practices; represented developers in Solutions Architecture discussions to unblock implementation
• Improved test coverage by coding unit tests for uncovered paths (20–30% hands-on coding); achieved zero attrition

Card Payment via Phone — Serverless microservice for agent-assisted IVR payment collection with CVV masking and SecureCo gateway integration

Stripe Subscriptions — Developed webhook handlers for mobile/energy subscriptions, structured Stripe products, published events to Kinesis

User Dashboard — Full-stack development (React + Node.js serverless) for customer account dashboard displaying linked subscriptions

CI/CD Migration — Led SnapCI → GoCD migration using 3 Musketeers pattern (Docker + Make + Compose) for Lambda deployments

Broadband Provisioning — Developed serverless APIs integrating with Australia’s NBN for service activation

Critical Production Incident — GCash API Abuse Mitigation

• Identified suspicious pattern in Splunk logs showing rapid backend API calls executing fraudulent 10,000 PHP transfers; coordinated emergency system shutdown and implemented rate limiting, enhanced API authentication, and transaction velocity checks

GCash Interoperability & Money-In Platform

• Developed REST API enabling seamless money transfers between PayMaya and GCash, processing hundreds of thousands of transactions monthly
• Architected unified balance inquiry microservice consolidating Smart Money and PayMaya legacy systems through intelligent routing
• Built multi-channel money-in platform integrating 6+ payment providers (OTC, kiosks, bank transfers, SM remittance centers)
• Developed Spring Batch application for automated daily merchant transaction reports; implemented Jenkins CI/CD quality gates across 5 refactored microservices

• Developed Java web services and fullstack back-office applications for BDO’s IVRS processing hundreds of thousands of monthly calls (balance inquiries, credit card status, prepaid mobile reload)
• Critical Security Enhancement: Developed Telephone PIN Web Service with enhanced authentication + IVR Prepaid Mobile Reload Limit Detection Web Service with configurable velocity checks (weekly/bi-weekly/monthly) — confirmed by management to have strengthened fraud prevention
• IVR Back-Office App (Built from Scratch): Architected fullstack system using Struts-Spring-Hibernate with Maker-Checker Approval Workflow and Role-Based Access Control (RBAC); built configuration portal for IVR operations team (channel controls, hold music, reload limits, heatmap analytics)

• Developed and maintained Java SOA applications for Globe Telecom’s prepaid systems supporting hundreds of thousands to millions of subscribers
• Maintained Java web service for Touch Mobile user eligibility within IBM WebSphere BPEL orchestration flows
• Developed Shell/AWK automation scripts computing subscriber transactions for promo eligibility — reduced campaign time to market from 3 weeks to days
• Conducted code reviews and authored UAT and production deployment workplans