Worked on internal full-stack tools across frontend, backend, databases, and production monitoring.
- Created reusable frontend components to standardize common UI patterns.
- Improved slow APIs by tracing bottlenecks in Datadog, then adding database indexes and caching.
- Added request and trace IDs to API requests to make debugging easier.
- Migrated application logging from console output to Pino.
- Set up Datadog alerts for critical flows.
- Handled internal features through requirements, technical documentation, testing, UAT, deployment, and production monitoring.
Tech stackReact · Angular · Express.js · NestJS · MySQL · BigQuery · Datadog · AWS · Docker
Developed and supported 11 production apps, 7 frontend and 4 backend, used by thousands of internal users in 15+ countries.
- Built a 2FA backend service for internal portals from scratch, including system design, caching, infrastructure, CI/CD, and security.
- Improved response time on two critical API endpoints by 17% and 46% with caching and HTTP connection pooling.
- Built an MCP server for AI-assisted frontend debugging and 2 VS Code extensions used by the team.
- Presented the 2FA design and implementation at a department townhall with 100+ engineers, PMs, and QA from Indonesia, Singapore, and China.
- Created AI agent skills and coding rules to support AI-assisted development.
- Provided on-call support and investigated application issues using APM and logs.
Tech stackTypeScript · Go · React · Vue · Next.js · Express.js · NestJS · Redis · MySQL · Playwright · GitLab CI/CD
Developed and maintained 6 production frontend apps used by thousands of internal users in 15+ countries.
- Built an internal portal frontend from scratch for thousands of internal users in 8 countries. Defined the architecture, testing setup, and CI/CD.
- Built an automated GitLab CI/CD deployment pipeline used by 3 teams.
- Migrated end-to-end tests from Cypress to Playwright, cutting test execution time by 70%.
- Upgraded core frontend libraries, cutting bundle size by 43% and improving First Contentful Paint by 15%.
- Created shared UI conventions, utilities, and components used across the team's frontend apps.
- Researched JavaScript big-number precision issues and published an internal npm library used by the team.
- Wrote technical designs and risk analyses, and reviewed them with product managers, backend engineers, and QA.
- Added frontend logging and monitored Sentry errors to investigate production issues.
- Created coding and E2E testing guidelines for AI agents, including instructions for new pages and shared utilities.
Tech stackTypeScript · React · Vue · Ant Design · Tailwind CSS · Playwright · Cypress · Jest · Sentry · GitLab CI/CD
Designed, built, published, and maintained Android apps independently through Duduu Studio.
- Developed entertainment and productivity apps for Google Play using Java and Kotlin.
- Built Oh My Bear Cute Stickers, which went on to reach 1M+ downloads.
- Used Firebase analytics and user feedback to guide updates, maintaining a 99%+ crash-free rate.
- Used Play Asset Delivery for sticker packs and Play Feature Delivery for less-used editing features to reduce Android app bundle size.
Tech stackJava · Kotlin · Firebase · Supabase · PostgreSQL · Play Asset Delivery · Play Feature Delivery
Developed and maintained internal applications used by multiple departments.
- Worked across frontend, backend, and Microsoft SQL Server using Ruby on Rails and Ember.js.
- Upgraded Ruby on Rails and checked compatibility between existing and updated code.
- Worked on database design, deployment, and bug fixes for internal applications.
Tech stackRuby · Ruby on Rails · JavaScript · Ember.js · Microsoft SQL Server · Linux
Assisted programming laboratory classes in Java and C.
- Assisted Advanced Object-Oriented Programming labs in Java from Feb to Jun 2020.
- Assisted Introductory Programming labs in C from Oct 2020 to Jan 2021.
Tech stackJava · C