Experience

Where I've worked and what I've done.

Software Engineer Intern

Current

PayPal Holdings Inc.Global ComplianceJun 2026 - Dec 20267 months

Architecting a full-stack portal (React, Redux, Java, Spring, Node.js) that serves PII verification documents for PayPal's entire global userbase, building a backend-for-frontend layer that orchestrates internal microservices, external vendor APIs, and decrypted Oracle data behind dual step-up SSO authentication and fine-grained, per-document RBAC.
Optimised long-running legacy endpoints from over 60 seconds down to under 1 second by introducing query optimizer hints, targeted indexes, and restructured join strategies across the underlying data access paths.
Redesigned the database schema to support an ongoing migration to a Milvus-based vector database, unlocking similarity search over verification documents to power automated duplicate and fraud detection.

JavaSpringReactReduxNode.jsTypescript

Home Team Science & Technology Academy (HTX)xDigitalDec 2025 - Apr 20265 months

Built a PromptOps platform adopted by 20+ engineers across the organisation (Next.js, FastAPI, Kubernetes, MLflow, Docker), automating iterative prompt evolution through GEPA and MIPROv2 optimisers layered with custom metaprompting heuristics for fully metric-driven prompt tuning.
Designed multi-agent workflows (LangChain, LangGraph, DSPy) with sub-agent orchestration and tool calling, powering 10+ production AI use cases that sustain >90% accuracy on LLM-as-judge evaluation metrics.
Engineered and shipped a ministry-wide product portal (Next.js, Nest.js, Milvus, Kubernetes, Docker) featuring semantic search and a built-in RAG assistant, centralising the discovery of 10+ departmental AI products across MHA.

Next.jsFastAPINest.jsPythonTypescriptLangChain

Central Provident Fund Board (CPF Board)Investment SystemsMay 2025 - Oct 20256 months

Built 10+ Spring Batch jobs integrated with the IBM Mainframe via JCL, applying idempotent step design and chunked, partitioned execution to reliably handle large-scale financial processing across millions of records.
Migrated 10+ legacy COBOL components to Java, rebuilt their interfaces as Spring APIs validated with SoapUI, and implemented JUnit test suites that reduced UAT defects by ~30%.
Reduced average runtime by ~30% across batch pipelines by profiling and optimising Java hotspots with Java Flight Recorder and JDK Mission Control, and tuning DB2 SQL queries through multi-row fetch, commit-frequency tuning, and lock-escalation prevention.
Pioneered the transition to automated regression testing with UiPath scripts and custom Python tooling, cutting end-to-end testing time by ~70%.
Resolved production issues and maintained build quality using Azure DevOps, Jenkins, SonarQube, and Jennifer APM across every SDLC phase (DEV → SIT → UAT → PROD).

JavaSpringIBM MainframeJUnitUiPathSoapUI

Energy Wave Worldwide Pte LtdLogistics DepartmentSep 2020 - Feb 20216 months

Spearheaded the shift from manual Excel tracking to an inventory management system (Orca Scan), introducing VBA automation for inventory and accounts, cutting manual entry by 50% and maintaining 100% stock accuracy.
Pioneered a Kanban workflow system to visualise tasks, improve communication, and streamline processes, boosting efficiency by 25% and reducing turnaround times by 30%.
Managed five special-needs staff through structured task delegation, improving timeliness and productivity by 50%.

VBAOrca ScanMicrosoft Excel