Priceline

Travel company under Booking Holdings

I led technical design and implementation of high-traffic, consumer-facing travel e-commerce products with ~XB in annual transactions and ~XMM visitors.

This work often involved initiating discussions with stakeholders, communicating across multiple teams across the organization, and creating backlogs of requirements for project deliverables in agile development workflows.

I also gave tech talks at company-wide development showcases about these web development initiatives:

• Server-side rendering & Hydration
• Setting Up Backing Services For 12-Factor App Development

My skill sets include:

• ES6 JavaScript
• TypeScript
• Babel JavaScript Compiler
• React JavaScript Library with Context/Hooks
• Redux State Management
• Node JavaScript Runtime with Express Framework
• GraphQL Query Language with Apollo API Platform
• Webpack Module Bundler
• Logging and Monitoring with Splunk/New Relic/GKE Stackdriver
• Automating development workflows with Github Actions
• Deployment with Docker/Harness/Codefresh
• GenAI workspace integration with Cursor

Here are my contributions grouped by year:

2025

• building Tailwind CSS & Base UI, Vaul, Embla based React components for a new Design System used for all product teams at Priceline
• migrating from Styled Components and integrating Tailwind CSS and new Design System into web applications
• creating time-sensitive marketing promotions and filters in Hotel web applications
• reducing Rental Cars landing page's Largest Contentful Paint (LCP) metric by ~2 seconds by utilizing CDN assets and eager loading of the Hero background image

2024

• leading an alternative Rental Cars supplier launch (multi-quarter project) by creating MVP requirements & backlog of engineering tasks and initiating discussions with stakeholders
• enhancing the Rental Cars map experience by creating map link per every vehicle pickup location - clicking on the link takes the user to map view where it highlights and auto-scrolls to the selected rate with an active map pin
• upgrading our web applications to the React 18 ecosystem by deep diving into Webpack, Loadable Components, Static Server-Side Rendering vs Streaming Server-Side Rendering of HTML, Styled Components, and JavaScript Compilation with Babel
• designing technical roadmap of client business logic migration to GraphQL and setting guidelines together with the team
• updating Github Action workflows to auto-deploy on QA environments and enhancing developer productivity by shaving off 0.5-1hr of manual deploy time
• updating internal slack Github Action workflow so that engineers can set the base git branch and notify the changes against base branch on Slack
• assisting with Google Analytics 3 to 4 migration in coordination with the Analytics Team, improving event-driven data tracking of customer behaviors across products
• handling internal server errors so that users are redirected to validation pages showing informative error messages based on error codes with options to redo the search
• advocating development of a shared vehicle listings card in Monorepo to be used across Rental Cars paths (Cross-Sell in Hotels and Flights, Upsell in Post Booking, Upgrade in Checkout, White Label, Packages, Standlone RC)
• proposing performance improvement plans in collaboration with Performance Guild (introducing Webpack module alias for aligning depedencies & multiple Webpack entry points for tree shaking & Streaming SSR workarounds with React 18 & Landing Background Image Download on First Paint & Stellate GraphQL Edge Partial Query Caching for caching API requests & Treo Lighthouse Pages with and without marketing scripts)
• participating in engineering management hiring interviews
• building a personality based & internal GenAI API powered trip recommendation quiz in a team of 5 at the Priceline Hackathon

2023

• building the data sequence diagram and implementing solutions for the Car Upgrade in Checkout feature (multi-quarter project) that successfully launched with 4.6% conversion rate
• refining scopes and requirements for Packages Full Listings (multi-quarter project) which launched with 90% win probability and enabled Rental Cars listings to be featured during customers' Packages search
• onboarding a junior engineer and helping make contributions across 3+ codebases to integrate special equipments pricing in checkout and collect commissions from suppliers (which exceeded expected attach rate by ~10%)
• creating utility functions that transform old data format to new Unified Search (for Packages Full Listings launch) & Checkout (for Car Upgrades launch) schemas
• building a checkout reference document or "cheat sheet" for engineers working on Legacy Cart to Universal Checkout migration
• participating in hiring interviews for co-op student program

2022

• serving as main point of contact for Rental Cars Web UX and iOS team in iOS team’s migration from using REST API to GraphQL
• leading Fullstory implementation across web apps to mask personal data in all PII elements
• fixing point of sale pricing bugs by investigating Stackdriver logs and updating the request-handler library in Monorepo
• developing some of the most used filters ("Deals", "Save Your Budget", "Price", and "Shuttle" filter)
• introducing "edit search" modal on mobile view
• supporting screen readers and web accessibility by updating meta viewport tags (removing user-scalable="no" parameters and maximum-scale parameter set to less than 5) and adding aria-label to elements

2021

• migrating our web apps from static to streaming server-side rendering for fast TTFB (note: in 2024 we reverted to static SSR due to Styled Components not being compatible with React 18 Streaming API)
• advocating 12-factor app goals during on-prem to cloud migration by setting up backing services for web applications with environment variables (and by pushing updates to .env file, Webpack build configurations, Priceline internal development tool environment setups, Harness templates, and GKE stackdriver logs) - as a result our team was able to test changes in sandbox, on-prem, and cloud environments by easily switching backing services per environment
• solving memory leak issues that caused Kubernetes pod restarts by investigating Splunk & New Relic garbage collection logs and updating DockerFile configuration (which stopped PagerDuty alerts for our team)
• suggesting usage of lazy loading solutions to improve mobile filters and "load more" performance which decreated time to visually complete
• adding a reusable business promotions GraphQL operation to be shared across products
• investigating marketing pixels behaviors across pages to determine if they should be fired per every user interaction

2020

• introducing Cypress end-to-end testing, setting up environment configurations, creating example spec files, and laying groundwork for cross-browser and A/B testing (note: in 2024 it was replaced by Mabl)
• resolving lat/long issues on map view to correctly show rental cars counter locations
• fixing map view so that map height is size of the screen and not larger than the customer's screen
• adding new sorting logic for deep linked Kayak searches
• implementing deep link when selecting counter locations from homepage Typeahead
• building merchandising/promotion banners based on business requests and updating the carousel banners display to make the navigational arrows stay in the right places
• winning Grand Prize with my friend Alvin at the Priceline Hackathon for a project that visualizes a customer's rental cars trip on a map with optimized routes (afterwards we met with the CPO to discuss opportunities to ship in production)

2019

• advocating usage of WebP (with Fastly configurations in the edge layer) to support lossness compression and faster loading of web images
• supporting type safety by migrating Rental Cars landing page to use TypeScript with updates to Webpack, Jest, TS, Babel configurations and migrating .js files to use .ts & .tsx
• introducing "scroll to top" button at the bottom of the page
• investigating drop on mobile homepage ad unit impressions and working with the marketing team to reload new Tealium rules
• fixing a deep linking point of sale issue where users were seeing international displays on domestic searches
• refactoring "Car Type" filter to show/hide car types based on size and category
• aligning the date format used on international point of search web pages and translated pages in listings and checkout

Hydrogen

B2B SaaS fintech & blockchain startup, early stage

I was part of the core team that built "Hydro: Security & Identity," an Ethereum blockchain-based identity management app (dApp). It launched for iOS and Android in July 2018.

Read more about my experience with the team on developing the app with React Native here.

How the 2FA app works:

• It creates a secure Ethereum wallet on your phone and saves your public Ethereum address mapped to a HydroID on the Ethereum blockchain.
• 12 seed words are also randomly generated at the time to restore your wallet in case you replace or lose your phone.
• Every time you authenticate with a linked website by entering a random 6-digit code that is shown on the website into the mobile app, a signed transaction is initiated on the blockchain, our immutable public ledger.
• Finally, the API checks if the smart contract has validated the transaction and authenticates your identity with the website.
• Touch ID, facial recognition, and PIN protection are also features offered by the Hydro app to provide you an extra layer of security.

Moreover, I developed sample apps with web3.js, such as this code which performs authentication via our smart contract. A detailed walk-through of the code is available here.

Some of my other projects include demos and admin & analytics tools interacting with our core financial API suite. Our team used React/Redux, Angular1, Node/Express, and C3.js.

I also presented sales demos to potential clients and built technical prototypes at proof-of-concept workshops (which included fun work trips to Chile which I am still thankful for).

Hedgeable

B2C fintech startup, early stage

I was the hired as the 7th employee to join Hedgeable in 2016 while Hedgeable was a seed stage startup. I reported directly to the CTO while we grew to 30+ employees.

My primary role was building the interfaces of our new investing and wealth management platform. I scaffolded the Angular2 & Node/Express single page application based on the original JavaScript & PHP multi page application.

Some of the things I built with our team of engineers and designers include data visualizations of client portfolios in d3.js and c3.js, landing page, session management with Redis, and user interfaces of the two-factor authentication app.

Company closed the investing platform in 2018 and spinned off to a B2B fintech platform called Hydrogen.

Patron

Arts network startup, early stage

I built Patron's alpha product in a globally distributed team of engineers in 2015. I used Angular1 & Node to build the web platform, deployed changes on Heroku, and reported directly to the CEO.