Hao Xu, Developer in Palo Alto, CA, United States
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Hao Xu

Verified Expert  in Engineering

Bio

Hao is a back-end engineer and full-stack veteran with a proven track record of developing services and software solutions for various companies, ranging from small startups to big top-notch corporations. His expertise spans eCommerce, social applications, games, software infrastructures, DevOps, SaaS, and algorithms. Hao is also proficient in big data, AI, and large language models (LLMs) and excels in executing projects and effectively communicating his ideas.

Portfolio

Imagemakers Inc.
Symfony, PHP, Git, AWS, CSS, HTML, AngularJS, Amazon EC2, Amazon S3...
Dealermade LP
ZIO, Scala, Profiling, Java Development Kit (JDK), JavaFX, Monitoring...
Instacart
Ruby, JavaScript, AWS, OpenAI, Back-end Developers, OpenAI GPT-3 API, GPT-4...

Experience

Availability

Full-time

Preferred Environment

Full-stack, Web3, Ruby on Rails (RoR), Python, Go, Java, C++, Cloud, JavaScript, Algorithmic Trading

The most amazing...

...thing I've accomplished is building multiple applications for startups and large systems, supporting companies from their early stages through growth and IPOs.

Work Experience

Back-end Symfony and AWS Developer

2024 - 2024
Imagemakers Inc.
  • Built many new features according to business requirements and KTLO.
  • Guided and built the spammer/reCAPTCHA verification to fight against spammers.
  • Oversaw the Symfony framework maintenance work and deployment flow.
  • Developed new emails and enhanced a new search capability.
Technologies: Symfony, PHP, Git, AWS, CSS, HTML, AngularJS, Amazon EC2, Amazon S3, Concurrency, Containerization, Google Sheets Development, Automation, Nginx, Azure Kubernetes Service (AKS), Middleware, Oracle Development, Relational Database Services (RDS)

Senior Scala Developer | Zio Framework Expert

2024 - 2024
Dealermade LP
  • Diagnosed and provided guidelines for the performance and scalability issues of the ZIO/Scala framework.
  • Developed a Scala async framework solution to scale up/out the current system.
  • Provided a new architecture, roadmap, and operation process/documents for the company to use in future development.
Technologies: ZIO, Scala, Profiling, Java Development Kit (JDK), JavaFX, Monitoring, API Observability, Observability Tools, Git, Containers, Amazon, Apache Ant, IntelliJ IDEA, Trading Bots, Big Data Architecture, Big Data Architecture, Concurrency, Containerization, Google Sheets Development, Automation, Google API, Nginx, Azure Kubernetes Service (AKS), Azure, Image Generation, Elastic, Middleware, RxJava, Spring, Unix, AWS Lambda, API Connectors, Cloud Architecture, PDF, Object-oriented Programming (OOP), JVM, Relational Database Services (RDS)

Tech Lead

2020 - 2022
Instacart
  • Built the full-stack customer platform and front end for web, mobile web, iOS, and Android.
  • Architected the chat and recommendation based on ML, OpenAI GPT API, private LLMA, Finetune, RAG, and LangChain.
  • Contributed to the infrastructure and DevOps to ensure the Instacart platform ran smoothly.
  • Served as a tech leader in building the Instcart eCommerce platform with Ruby on Rails and GraphQL, the world's biggest Ruby on Rail deployment.
  • Architected and built a user authentication platform in Go, serving hundreds of millions of users.
Technologies: Ruby, JavaScript, AWS, OpenAI, Back-end Developers, OpenAI GPT-3 API, GPT-4, Linux, Stripe Development, Stripe Payments, Artificial Intelligence, Artificial Intelligence, Data Science, RAG, Generative Pre-trained Transformers (GPT), Continuous Integration (CI), Web Services, Data Science, GitHub, Deep Learning, Data Science, NumPy, RabbitMQ, Laravel, Blade Templates, React.js, ChatGPT, Midjourney, Firebase, TypeScript, CSS, Scraping, E-commerce marketing, Google Analytics, SEO, gRPC, Snowflake, Back-end Developers, Redis, Spark, LLM, Express.js, MERN Stack, MongoDB, Google Cloud Development, Bots, Cloud Infrastructure, Selenium, Full-stack, Docker Hub, API, Reddit, PostgreSQL, BigQuery, Business Intelligence Development, Ruby on Rails, Google Drive Development, Content Management Systems (CMS), API Integration, Beautiful Soup, Google Cloud Functions, Cron, Elasticsearch, OpenAI Assistants API, Prompt Engineering, Gmail API, Gmail, Email, SDK Development, SDKs, AWS, Serverless Architecture, Serverless, Pinecone, LlamaIndex, Poetry, Computer Networking, Software Engineering, Tailwind CSS, Android, Cross-Platform, Mobile App Design, Mobile App Design, Software Architecture, iOS, Android, Kotlin, Flutter, React Native, Swift, Mapbox, Navigation, Electric Vehicles, Fivetran, Expo, Azure, Identity & Access Management (IAM), Azure Active Directory B2C (ADB2C), OpenID Connect (OIDC), SAML, OAuth, Duende, IdentityServer 4, SAML-auth, SecOps, Next.js, Hashistack, AI Website Builders, Mobile App Design, Leadership, Scalability, Technical Leadership, Startup Development, Coaching, Engineering, Process Development, Virtual Coaching, Azure OpenAI Service, Blazor, Load Testing, Web Development, Amazon Simple Queue Service (SQS), Apache, Google Analytics 4 (GA4), Microsoft Power Apps, SharePoint Design, Office 365, Office 365 API, APIs, REST API, Interim CTOs, PWA, Progressive Web Applications (PWAs), Electron.js, Algolia, Gemini API, DNS, SEO Tools, Django, Spring Boot, Pandas, Google Sheets API, Hardware, Low-level Programming, MacOS, MDM, Jamf, Mobile Device Management (MDM), Zapier Development, Scala, ZIO, Profiling, Amazon EC2, Amazon S3, AngularJS, RSpec, Ruby on Rails, Java Development Kit (JDK), JavaFX, Accessibility Development, Shopify, Django, Monitoring, Machine Learning Operations (MLOps), Databricks, OpenTelemetry, Big Data Architecture, API Observability, Data Warehouse, Amazon SageMaker, Prometheus, Observability Tools, Website Data Scraping, Dart, GStreamer, Git, JSON, XML, Java, Containers, Stable Diffusion, ElevenLabs Solutions, Chatbot Development, Live Chat, Crawlee, Amazon, HIPAA Compliance, Apache Tomcat, Apache Ant, IntelliJ IDEA, Zendesk Development, NoSQL, Cassandra, Python API, Big Data Architecture, Big Data Architecture, Data Science, Data Handling, Concurrency, Generative Artificial Intelligence (GenAI), OpenAI API, Containerization, Google Sheets Development, Google Apps Script, Automation, Google API, Nginx, Flask, CheerioJS, Goutte, FastAPI, Python, Performance Tuning, WebSockets, Asyncio, Azure Kubernetes Service (AKS), Azure, Time Series Modeling, GTK, HTML5, Image Generation, Automated Testing, PagerDuty, Testing, SOC 2( Service Organization Control), Google Maps Development, Google Maps Development, Mapbox SDK, Mapbox API, Figma, MongoDB, Elastic, Middleware, Jetpack Compose, RxJava, MVC Frameworks, Quarkus, Spring, Large Scale Distributed Systems, SSO Engineering, Technical Architecture, Technical Writing, Mobile Apps, Redux, Babel, Large-scale Projects, Webpack, Unix, WildFly, Oracle Development, AWS Lambda, Microsoft Power Platform, Microsoft Power Pages, Business Intelligence Development, Social Security, IDP, API Connectors, Cloud Architecture, Airtable, PDF, Object-oriented Programming (OOP), Microservices Architecture, Front-end, JVM, Team Leadership, Relational Database Services (RDS), C++, Linux

Tech Lead

2019 - 2020
Roblox
  • Built the microservice infrastructure and DevOps for the Roblox platform.
  • Architected the user spammer, user suspicion detection, and prevention system.
  • Improved the platform's performance and scalability to support 10x growth.
  • Built next-generation mesh services in Go, handling millions of queries per second and serving hundreds of millions of users.
Technologies: AWS IAM, E-commerce Development, OpenAI, Machine Learning, Infrastructure, Cloud Engineering, System Design, Linux, GNU Debugger (GDB), Boost, CMake, Stripe Development, Artificial Intelligence, Continuous Integration (CI), Web Services, C#, GitHub, Deep Learning, Data Science, NumPy, RabbitMQ, ASP.NET, gRPC, Snowflake, Back-end Developers, Redis, Spark, Apache Thrift, Qt Development, Google Cloud Development, Bots, Cloud Infrastructure, Docker Hub, BigQuery, Integration, Content Management Systems (CMS), Cron, Elasticsearch, Gmail API, Gmail, Email, Back-end Developers, .NET Core, SDK Development, SDKs, AWS, Serverless Architecture, Serverless, Computer Networking, Software Engineering, Android, Cross-Platform, Mobile App Design, Mobile App Design, Software Architecture, iOS, Android, Swift, Azure, Identity & Access Management (IAM), Azure Active Directory B2C (ADB2C), OpenID Connect (OIDC), SAML, OAuth, Duende, IdentityServer 4, SAML-auth, SecOps, Next.js, Hashistack, Leadership, Scalability, Technical Leadership, Startup Development, Coaching, Engineering, Process Development, Virtual Coaching, Azure OpenAI Service, Blazor, Load Testing, Web Development, Amazon Simple Queue Service (SQS), Apache, Google Tag Manager, Google Analytics 4 (GA4), Microsoft Power Apps, SharePoint Design, Office 365, Office 365 API, APIs, REST API, Interim CTOs, PWA, Progressive Web Applications (PWAs), DNS, SEO Tools, HubSpot Development, Pandas, Google Sheets API, Windows Development, Low-level Programming, MacOS, MDM, Mobile Device Management (MDM), Profiling, Amazon EC2, Amazon S3, Java Development Kit (JDK), Embedded Rust, Embedded Systems Engineering, Accessibility Development, Shopify, PySide, Monitoring, Machine Learning Operations (MLOps), Databricks, OpenTelemetry, Big Data Architecture, API Observability, Data Warehouse, Amazon SageMaker, Prometheus, Observability Tools, Website Data Scraping, Dart, GStreamer, Git, JSON, XML, Crypto, Containers, JSII, ElevenLabs Solutions, Amazon, FileZilla, HIPAA Compliance, HL7, PuTTY, Agile Development, IntelliJ IDEA, NoSQL, Cassandra, Python API, Big Data Architecture, Big Data Architecture, Data Science, Data Handling, Containerization, Embedded Software Engineering, Google Sheets Development, Google Apps Script, Automation, Google API, Nginx, Flask, FastAPI, Python, Performance Tuning, WebSockets, Asyncio, Azure Kubernetes Service (AKS), Time Series Modeling, GTK, HTML5, Kubernetes, Automated Testing, PagerDuty, Testing, SOC 2( Service Organization Control), Go, Google Maps Development, Google Maps Development, MongoDB, Elastic, Middleware, .NET MAUI, Xamarin, Jetpack Compose, jQuery, MVC Frameworks, Large Scale Distributed Systems, SSO Engineering, Technical Architecture, Technical Writing, Visual Studio Development, Mobile Apps, Babel, Large-scale Projects, Webpack, Hibernate, Unix, Oracle Development, AWS Lambda, Microsoft Power Platform, Microsoft Power Pages, Social Security, Airtable, PDF, Object-oriented Programming (OOP), Microservices Architecture, JVM, Team Leadership, Relational Database Services (RDS), C++, Linux

Tech Lead

2016 - 2019
Uber
  • Spearheaded the development of the company's global real-time logistic platform for both back-end and client side.
  • Built a global intelligence platform tailored for conducting competitive analyses.
  • Created the next-generation driver system in Go to achieve a tenfold performance boost compared to the Node.js one.
Technologies: C++, Java, Go, Node.js, Cloudflare, Architecture, Logging, WordPress Development, Optimization, Servers, Web Development, Dynamic Load Balancing, Microservices Development, Platform as a Service (PaaS), Plugins, Rust, Blockchain, Web Scraping, APIs, ETL, Django, Redshift, AWS, Amazon Elastic Container Service (ECS), Database, System Security, CI/CD Pipelines, AWS Key Management Service (KMS), Terraform, HashiCorp, Keycloak, GraphQL, Data Structures, SQL, Algorithms, Database, Data Engineering, Data Lakes, Cloud Dataflow, Cloud Engineering, Orchestration, LangChain, Apache Beam, Web Development, API, Linear Algebra, Data Scraping, Web Development, Machine Learning, Git, Linux, GNU Debugger (GDB), Boost, DDS, CMake, Stripe Development, Stripe Payments, Artificial Intelligence, Artificial Intelligence, Data Science, Continuous Integration (CI), Web Services, Data Science, GitHub, Data Science, NumPy, RabbitMQ, PDF Scraping, Laravel, Blade Templates, React.js, Firebase, TypeScript, CSS, Scraping, E-commerce marketing, BigCommerce, Google Analytics, SEO, gRPC, C, Snowflake, Back-end Developers, Cassandra, Redis, Spark, Apache Thrift, Embedded C, Express.js, MERN Stack, MongoDB, Google Cloud Development, Bots, Cloud Infrastructure, Selenium, Full-stack, Docker Hub, Reddit, PostgreSQL, BigQuery, Business Intelligence Development, Google Drive Development, Bootstrap, Content Management Systems (CMS), Strapi, API Integration, Beautiful Soup, Google Cloud Functions, Cron, Elasticsearch, Gmail API, Gmail, Email, Back-end Developers, SDK Development, SDKs, AWS, Serverless Architecture, Serverless, Computer Networking, System Security, Software Engineering, Android, Cross-Platform, Mobile App Design, Mobile App Design, Software Architecture, iOS, Android, Flutter, React Native, Swift, Mapbox, Navigation, Electric Vehicles, Expo, Identity & Access Management (IAM), OpenID Connect (OIDC), SAML, OAuth, SAML-auth, SecOps, Hashistack, Mobile App Design, Buffer Management, Leadership, Scalability, Technical Leadership, Startup Development, Coaching, Engineering, Process Development, Virtual Coaching, Load Testing, Web Development, Amazon Simple Queue Service (SQS), Apache, Google Ads, Google Tag Manager, Google Analytics 4 (GA4), REST API, Interim CTOs, PWA, Progressive Web Applications (PWAs), DNS, htaccess, SEO Tools, HubSpot Development, Spring Boot, Pandas, Google Sheets API, C#, Low-level Programming, MacOS, Jamf, Mobile Device Management (MDM), Zapier Development, Profiling, Amazon EC2, Amazon S3, AngularJS, Java Development Kit (JDK), JavaFX, Embedded Systems Engineering, Artificial Intelligence, Accessibility Development, Shopify, Django, Django, PyQt, PySide, Monitoring, Machine Learning Operations (MLOps), Databricks, OpenTelemetry, Big Data Architecture, API Observability, Data Warehouse, Amazon SageMaker, Prometheus, Observability Tools, Website Data Scraping, Dart, GStreamer, JSON, XML, Crypto, Containers, JSII, Marketing Technology (MarTech), Crawlee, Amazon, FileZilla, HIPAA Compliance, HL7, PuTTY, Agile Development, Apache Tomcat, Apache Ant, IntelliJ IDEA, Apache Struts 2, NetBeans, Zendesk Development, NoSQL, Big Data Architecture, Big Data Architecture, Data Science, Data Handling, Concurrency, Containerization, Google Sheets Development, Google Apps Script, Automation, Google API, Nginx, Flask, CheerioJS, Goutte, FastAPI, Python, Performance Tuning, WebSockets, Asyncio, Azure Kubernetes Service (AKS), Azure, Time Series Modeling, GTK, HTML5, Kubernetes, Automated Testing, PagerDuty, Testing, SOC 2( Service Organization Control), Google Maps Development, Google Maps Development, Mapbox SDK, Mapbox API, Figma, Elastic, Middleware, Jetpack Compose, RxJava, jQuery, Apache, Spring, Large Scale Distributed Systems, SSO Engineering, Technical Architecture, Mobile Apps, XHTML, Redux, Babel, Large-scale Projects, Webpack, Unix, WildFly, Oracle Development, AWS Lambda, Microsoft Power Platform, Microsoft Power Pages, Microsoft Power Automate, Business Intelligence Development, Social Security, IDP, API Connectors, Cloud Architecture, Airtable, PDF, Object-oriented Programming (OOP), Microservices Architecture, Front-end, JVM, Team Leadership, Relational Database Services (RDS), C++

Senior Engineer

2017 - 2018
Airbnb
  • Built the async process framework based on Kafka and operated it.
  • Acted as a full-stack engineer building the dev portal and pipeline.
  • Created the infrastructure and DevOps for an Airbnb back end.
  • Built the world's biggest travel eCommerce marketplace with Ruby on Rails and Java/Go.
Technologies: Ruby, Java, Machine Learning, AWS, Apache Kafka, Linux, Boost, CMake, Stripe Development, Stripe Payments, Data Science, Continuous Integration (CI), Web Services, GitHub, Data Science, NumPy, RabbitMQ, Firebase, TypeScript, CSS, E-commerce marketing, Google Analytics, SEO, Snowflake, Angular, Back-end Developers, Cassandra, Scala, Redis, Spark, Apache Thrift, Google Cloud Development, Heroku, Bots, Cloud Infrastructure, Selenium, Full-stack, Docker Hub, Ruby on Rails, Google Drive Development, Scrapy, Integration, API Integration, Beautiful Soup, Google Cloud Functions, Cron, Elasticsearch, Gmail API, Email, Back-end Developers, SDK Development, SDKs, AWS, Serverless Architecture, Serverless, Computer Networking, Software Engineering, Android, Cross-Platform, Mobile App Design, Mobile App Design, Software Architecture, iOS, Android, Kotlin, Flutter, React Native, Swift, Mapbox, Navigation, Expo, OpenID Connect (OIDC), SAML, OAuth, SAML-auth, SecOps, Mobile App Design, Scalability, Startup Development, Coaching, Engineering, Process Development, Virtual Coaching, Load Testing, Web Development, Amazon Simple Queue Service (SQS), Apache, Google Tag Manager, Google Analytics 4 (GA4), Office 365, APIs, REST API, PWA, Progressive Web Applications (PWAs), GoDaddy, SEO Tools, HubSpot Development, Spring Boot, Pandas, MacOS, Mobile Device Management (MDM), Profiling, Amazon EC2, Amazon S3, RSpec, Ruby on Rails, Java Development Kit (JDK), Accessibility Development, Monitoring, Machine Learning Operations (MLOps), Databricks, OpenTelemetry, Big Data Architecture, API Observability, Data Warehouse, Prometheus, Observability Tools, Git, JSON, XML, Java, Containers, Alibaba Cloud, HIPAA Compliance, Agile Development, Apache Ant, IntelliJ IDEA, Apache Struts 2, Zendesk Development, NoSQL, Python API, Big Data Architecture, Big Data Architecture, Data Science, Data Handling, Concurrency, Containerization, Embedded Software Engineering, Google Sheets Development, Google Apps Script, Automation, Google API, Nginx, Flask, FastAPI, Python, Performance Tuning, WebSockets, Asyncio, Azure Kubernetes Service (AKS), DNS, Time Series Modeling, GTK, HTML5, Automated Testing, PagerDuty, Testing, SOC 2( Service Organization Control), Google Maps Development, Elastic, Middleware, Apache, MVC Frameworks, MariaDB, Quarkus, Spring, Large Scale Distributed Systems, SSO Engineering, Technical Architecture, Technical Writing, Mobile Apps, XHTML, Redux, Babel, Large-scale Projects, Webpack, Hibernate, Unix, WildFly, Oracle Development, Microsoft Power Pages, Microsoft Power Automate, Business Intelligence Development, IDP, API Connectors, Cloud Architecture, Airtable, PDF, Object-oriented Programming (OOP), Microservices Architecture, Front-end, JVM, Relational Database Services (RDS), C++, SLAM, Simultaneous Localization & Mapping (SLAM)

CTO

2013 - 2015
Citrus Lane
  • Built the Citrus Lane website to support 200,000+ users on all platforms—web, iOS, and Android.
  • Developed systems to operate 100,000+ monthly subscriptions.
  • Created systems for the recurring bills of 100,000+ customers.
Technologies: PHP, Node.js, BigCommerce, Back-end Developers, Redis, Express.js, MERN Stack, MongoDB, Interim CTOs, Google Cloud Development, Heroku, Bots, Cloud Infrastructure, Selenium, Full-stack, Business Intelligence Development, Perl, Scrapy, Integration, Bootstrap, Content Management Systems (CMS), Strapi, API Integration, Beautiful Soup, Google Cloud Functions, Elasticsearch, Email, .NET Core, SDK Development, Software Engineering, Mobile App Design, Software Architecture, iOS, Android, Authorize.Net, OAuth, SecOps, CTools, Leadership, Technical Leadership, Startup Development, Coaching, Process Development, Virtual Coaching, Load Testing, Web Development, Google Ads, Google Tag Manager, Google Analytics 4 (GA4), Office 365, Office 365 API, APIs, PWA, Progressive Web Applications (PWAs), htaccess, GoDaddy, SEO Tools, HubSpot Development, MacOS, Symfony, Amazon EC2, Accessibility Development, Magento, Django, Django, PyQt, Monitoring, Data Warehouse, Observability Tools, Git, JSON, XML, Java, Containers, Marketing Technology (MarTech), Alibaba Cloud, eBay, HIPAA Compliance, HL7, PuTTY, Agile Development, Apache Ant, IntelliJ IDEA, Apache Struts 2, NetBeans, Python API, Big Data Architecture, Data Science, Data Handling, Concurrency, Containerization, Embedded Software Engineering, Google API, Nginx, Performance Tuning, Asyncio, Azure Kubernetes Service (AKS), Azure, DNS, GTK, HTML5, Image Generation, Automated Testing, Testing, Elastic, Middleware, jQuery, MVC Frameworks, MariaDB, Quarkus, Spring, Technical Architecture, Technical Writing, Mobile Apps, XHTML, Redux, Large-scale Projects, Hibernate, Unix, WildFly, Oracle Development, Microsoft Power Platform, Microsoft Power Pages, Business Intelligence Development, Cloud Architecture, PDF, Object-oriented Programming (OOP), Microservices Architecture, Front-end, JVM, Team Leadership, Relational Database Services (RDS), C++, SLAM, Simultaneous Localization & Mapping (SLAM)

Software Engineer

2012 - 2012
Google
  • Built the coupon ads and served billions of audience.
  • Architected a pipeline to analyze the performance and results of coupon ads.
  • Improved the foundation of the ad display and analytics platform.
Technologies: Java, C++, JavaScript, Algorithms, Linux, GNU Debugger (GDB), Boost, CMake, Artificial Intelligence, Data Science, Web Services, Data Science, GitHub, SEO, gRPC, C, Back-end Developers, Cloud Infrastructure, Business Intelligence Development, Google Drive Development, Integration, Content Management Systems (CMS), Elasticsearch, Gmail API, Gmail, SDK Development, Software Engineering, Software Architecture, Android, OAuth, SecOps, Scalability, Process Development, Load Testing, Web Development, Google Ads, Google Tag Manager, Google Analytics 4 (GA4), APIs, htaccess, SEO Tools, AngularJS, Accessibility Development, Monitoring, Data Warehouse, Observability Tools, JSON, XML, HL7, PuTTY, Apache Tomcat, Apache Ant, NetBeans, Python API, Big Data Architecture, Data Science, Data Handling, Concurrency, Google Sheets Development, Google API, Nginx, Performance Tuning, Automated Testing, Testing, Middleware, MVC Frameworks, Spring, Large Scale Distributed Systems, Technical Writing, Large-scale Projects, Unix, API Connectors, PDF, Object-oriented Programming (OOP), JVM, Relational Database Services (RDS), C++

Engineer

2005 - 2011
Yahoo!
  • Led a team to build Yahoo email. I built YOS, search, and ads platforms.
  • Acted as a full-stack engineer lead and built Yahoo Answers, Flickr, and many other social products.
  • Built many Yahoo infrastructure data pipelines and Hadoop stacks.
Technologies: PHP, JavaScript, C++, Java, Algorithms, Linux, GNU Debugger (GDB), Boost, CMake, Artificial Intelligence, GitHub, C, Back-end Developers, Qt Development, Bots, Cloud Infrastructure, Full-stack, API, Perl, Content Management Systems (CMS), Elasticsearch, SDK Development, Software Engineering, Software Architecture, iOS, Android, Load Testing, Web Development, htaccess, Symfony, JavaFX, PyQt, Data Warehouse, Observability Tools, JSON, XML, Java, PuTTY, Apache Tomcat, Apache Ant, Apache Struts 2, NetBeans, Big Data Architecture, Data Science, Performance Tuning, Automated Testing, Testing, Middleware, jQuery, Apache, MariaDB, Large Scale Distributed Systems, Visual Studio Development, XHTML, Large-scale Projects, Unix, Oracle Development, Microsoft Power Platform, Object-oriented Programming (OOP), Front-end, JVM, C++, SLAM, Simultaneous Localization & Mapping (SLAM)

Principal Engineer

2001 - 2005
Oracle
  • Built and supported the global platform of the Siebel system.
  • Architected the infrastructure and comm layer for the Siebel system.
  • Developed the analytics platform with a team for the Siebel system.
Technologies: C++, Java, JavaScript, Linux, GNU Debugger (GDB), Boost, GitHub, Back-end Developers, Google Cloud Development, Integration, Load Testing, Low-level Programming, JavaFX, Java, Performance Tuning, SOC 2( Service Organization Control), Middleware, Large Scale Distributed Systems, Visual Studio Development, Hibernate, Unix, Oracle Development, Object-oriented Programming (OOP), JVM, C++, SLAM, Simultaneous Localization & Mapping (SLAM)

Uber | Global Service Platforms

Uber, the leading company in the ride-sharing and gig economy, is driven by the concept of movement. Movement fuels the organization and is an integral part of its identity. They are constantly innovating and improving how they facilitate transportation, enabling customers to reach their desired destinations, acquire the things they need, and provide earning opportunities in locations across the globe. They strive to deliver these services in real time.

I worked for them as a tech lead, spearheading the development of their global real-time logistic platform, their global intelligence platform for competitive analyses, and the next-generation driver system.

Airbnb | Product and Service Infrastructure and Data Flow

http://www.airbnb.com
Airbnb's vision is to create a world where anyone can belong anywhere they go. It is built around the idea that everyone deserves to experience the perfect trip, choosing their accommodations, activities, and connections. With this in mind, they empower millions globally to become entrepreneurs by utilizing their spaces, interests, and skills. This is the audacious and rewarding mission to which Airbnb's diverse team is dedicated.

I integrated the team as a senior engineer and tech lead, contributing to the product and service infrastructure and the communication and data flow within the company's systems.

Google | Ads Project

http://www.google.com
Google's mission is to organize the vast amount of worldwide information and make it universally accessible and helpful. With billions of users in mind, they continuously strive to develop groundbreaking products and cutting-edge tools that shape the future.

I joined the project to combine the power of search and ads with AI technology, working on the ads UI and developing coupon ads.

Roblox | Platform Architecture

Roblox reimagines how people come together by enabling individual connections and fostering meaningful relationships in the Meta world. Roblox employees tackle complex questions and drive incredible innovation.

I worked at Roblox as a tech lead, handling their next-generation platform's architecture, development, and maintenance, moving from a monolithic to a microservice architecture.

Citrus Lane | Back-end Infrastructure, Website, and Apps

Citrus Lane is a startup providing children subscriptions. It serviced tens of thousands of children subscriptions and experienced a remarkable tenfold growth.

I joined them as a tech leader, leading the team to build the back-end infrastructure, website, and apps.

Siebel | Cross-platform Functionality

Siebel, the leading global customer relationship management (CRM) company, specializes in building enterprise software solutions.

I played a crucial role in developing the cross-platform functionality for Siebel, enabling seamless operation on Linux, IBM AIX, and Microsoft Windows, with support for multiple databases, including IBM Db2, Oracle, and Microsoft SQL Server.

Subsequently, Siebel was acquired by Oracle, marking a significant milestone in its history.

Yahoo | Platform, Infrastructure, and Data Storage Systems

http://www.yahoo.com
Yahoo's media, technology, and business platforms connect hundreds of millions of people worldwide to the things they love. With apps and sites like Yahoo Sports, Yahoo Finance, Yahoo Fantasy, and Yahoo Mail and a powerful, open platform that connects brands and publishers to passionate fans, they're all about putting an exclamation point on what users are into.

I worked at Yahoo as a principal engineer and tech lead, contributing to multiple tasks regarding the platform, infrastructure, and cloud data storage systems.

Algorithm Trading System

I built a trading system that generated signals based on the owner's various algorithms and did the auto trading. It was built on top of ib_insync. The system provides a framework for owners to plug in algorithms.

Student Class Selection System

An internal web system that allows students to select available classes. I built it on top of MySQL and Ruby on Rails. It comes with an admin dashboard, and it enables 500 students to choose among 20 classes based on various criteria and capacities.

Finance, Legal, and Web Scrap Project

A whole system to scrap many finance and legal systems with special requirements. This also involved a website for crud, alert, display, user management, and real-time communication to end users massively and swiftly.

Trading Bots

A Python-based trading system for trading. I utilized IB trading APIs, pine script on trading views, and other technologies. This is a system built for a private team.
They could plug in the specific algorithms.

DMX Cat

I designed, built, deployed, and maintained high-quality iOS and Android apps for Bluetooth and hardware applications. I also developed Mac, Windows, and Linux applications, as well as hardware and firmware. Additionally, I used C++ and client-side technologies in my work.

Video Conference

As a senior engineer, I built a system to support a hardware-based video system from end to end. I worked on many aspects of the project, from the client side and app to the firmware, video algorithm, and protocol for the startup. I also maintained the product, firmware, and app.

Ice Diamond

Built and maintained one of the biggest online diamond stores backed by top VC. I worked on eCommerce platforms, CRM, data analytics, SEO, operations, etc. As a tech leader, I hired and mentored tech people, working with the PM and DevOps on all initiatives.

Electronic Accessory

Served as a tech leader and led a team to build and maintain a top-level electronic accessory website that ranked at the top of the US market. I focused on SEO, the eCommerce platform, the database, operations, PHP, analytics, apps, payment, and Google Ads.

DeFi Solana Smart Contract Web3

I completed a project on the Solana blockchain that leverages smart contract technology to create a decentralized finance (DeFi) platform. The project focuses on enabling users to engage in yield farming, staking, and liquidity provision, utilizing Solana's high throughput and low latency features.

One of the Largest Lawyer Sites

I created a comprehensive website and app tailored for lawyers and their clients, including a robust pipeline and API integration for data collection, extraction, presentation, and querying specifically for US lawyers. Additionally, I managed DevOps responsibilities to ensure seamless deployment and maintenance.
1998 - 2001

Master's Degree in Computer Science

The University of New Mexico - Albuquerque, New Mexico, USA

1993 - 1998

Bachelor's Degree in Computer Science

Tsinghua University - Beijing, China

Libraries/APIs

Node.js, Stripe Development, Stripe Development, NumPy, React.js, Python API, Interactive Brokers API, TWS API, API, Ruby on Rails, Beautiful Soup, OpenAI Assistants API, Gmail API, Authorize.Net, Office 365 API, REST API, Pandas, Google Sheets API, ZIO, Django, PyQt, PySide, JSII, Crawlee, Puppeteer, OpenAI API, Google API, Solana.py, CheerioJS, Goutte, Python, Asyncio, Google Maps Development, Google Maps Development, Mapbox API, RxJava, jQuery, Vue.js

Tools

Logging, Amazon Elastic Container Service (ECS), AWS Key Management Service (KMS), Terraform, HashiCorp, Cloud Dataflow, Git, GNU Debugger (GDB), CMake, GitHub, RabbitMQ, ChatGPT, Google Analytics, Docker Hub, BigQuery, Cron, Android, Expo, Azure Active Directory B2C (ADB2C), Hashistack, Azure OpenAI Service, Amazon Simple Queue Service (SQS), Apache, Microsoft Power Apps, Zapier Development, RSpec, Java Development Kit (JDK), Amazon SageMaker, Observability Tools, FileZilla, PuTTY, Apache Tomcat, Apache Ant, IntelliJ IDEA, Google Sheets Development, Nginx, Azure Kubernetes Service (AKS), Azure, GTK, Figma, MongoDB, Elastic, Apache, Visual Studio Development, Babel, Webpack, WildFly, Microsoft Power Pages, Business Intelligence Development, Keycloak, Apache Beam, AWS IAM, CTools, Seos

Languages

Python, Go, Java, C++, Ruby, JavaScript, HTML, PHP, Rust, GraphQL, SQL, C#, TypeScript, CSS, C, Snowflake, Scala, Embedded C, Perl, Kotlin, Swift, SAML, Dart, XML, Google Apps Script, HTML5, Visual Basic, XHTML, C++, Python, Pine Script

Frameworks

Ruby on Rails, .NET, Cascades, Django, Boost, Laravel, ASP.NET, gRPC, Spark, Apache Thrift, Qt Development, Express.js, Selenium, Scrapy, Bootstrap, .NET Core, LlamaIndex, Tailwind CSS, Flutter, React Native, OAuth, IdentityServer 4, Next.js, Blazor, Electron.js, Spring Boot, Symfony, AngularJS, Django, Big Data Architecture, GStreamer, Java, Apache Struts 2, Flask, .NET MAUI, CakePHP, Spring, Redux, Hibernate, Angular

Paradigms

DevOps, Web Development, Microservices Development, ETL, API, Continuous Integration (CI), SEO, Business Intelligence Development, Serverless Architecture, Cross-Platform, Mobile App Design, Load Testing, API Observability, HIPAA Compliance, Agile Development, Automation, Automated Testing, Testing, Object-oriented Programming (OOP), Microservices Architecture

Platforms

Linux, Apache Kafka, Docker, Kubernetes, Windows Development, WordPress Development, AWS, Cloud Engineering, Firebase, BigCommerce, DigitalOcean, Heroku, Mobile App Design, iOS, Android, Mapbox, Azure, Google Ads, SharePoint Design, Algolia, HubSpot Development, MacOS, Amazon EC2, Ruby on Rails, JavaFX, Magento, Shopify, Databricks, Amazon, NetBeans, Zendesk Development, PagerDuty, Xamarin, Unix, Oracle Development, AWS Lambda, Microsoft Power Platform, Microsoft Power Automate, JVM, Linux, Blockchain, E-commerce Development, Wand

Storage

MySQL, PostgreSQL, NoSQL, Redshift, Database, Data Lakes, Cassandra, Redis, MongoDB, Google Cloud Development, Elasticsearch, AWS, Amazon S3, JSON, Alibaba Cloud, MariaDB, Database

Industry Expertise

Virtual Coaching, Accounting, Trading Systems

Other

Software Development, Software Development, Full-stack, Cloud Engineering, Distributed Systems, Machine Learning, Competitive Intelligence, Infrastructure, SaaS, Cloudflare, Architecture, Optimization, Servers, Platform as a Service (PaaS), Web Scraping, APIs, CI/CD Pipelines, Data Structures, Algorithms, Data Engineering, Orchestration, Web Development, Linear Algebra, Data Scraping, Web Development, OpenAI, System Design, Back-end Developers, OpenAI GPT-3 API, GPT-4, Stripe Payments, Artificial Intelligence, Artificial Intelligence, Data Science, RAG, Generative Pre-trained Transformers (GPT), Web Services, Algorithms, Data Science, Deep Learning, Data Science, Blade Templates, Scraping, E-commerce marketing, Back-end Developers, LLM, MERN Stack, Interim CTOs, Bots, Cloud Infrastructure, Full-stack, Reddit, Google Drive Development, Integration, Content Management Systems (CMS), API Integration, Google Cloud Functions, Trading, TradingView Development, Cryptocurrency, Prompt Engineering, Gmail, Email, SDK Development, SDKs, Serverless, Pinecone, Poetry, Computer Networking, System Security, Software Engineering, Software Architecture, Navigation, Electric Vehicles, Fivetran, Identity & Access Management (IAM), OpenID Connect (OIDC), Duende, SAML-auth, SecOps, Mobile App Design, Advisory, Leadership, Scalability, Technical Leadership, Startup Development, Coaching, Engineering, Process Development, Web Development, Google Tag Manager, Google Analytics 4 (GA4), Office 365, PWA, Progressive Web Applications (PWAs), Gemini API, DNS, htaccess, GoDaddy, SEO Tools, Hardware, Firmware, Low-level Programming, USB, MDM, Jamf, Mobile Device Management (MDM), Fintech Development, Profiling, Embedded Rust, Embedded Systems Engineering, Artificial Intelligence, Accessibility Development, Monitoring, Machine Learning Operations (MLOps), OpenTelemetry, Data Warehouse, Prometheus, Website Data Scraping, Solana, Crypto, Containers, Stable Diffusion, Marketing Technology (MarTech), ElevenLabs Solutions, Chatbot Development, Live Chat, eBay, HL7, Trading Bots, Big Data Architecture, Big Data Architecture, Data Science, Data Handling, Concurrency, Generative Artificial Intelligence (GenAI), Containerization, Embedded Software Engineering, Decentralized Finance (DeFi), Finance, Equities, Equity Trading, Hedge Funds, Options Trading, Profit & Loss (P&L), Stock Market Consulting, Financial Software Development, Trade Finance, Fund Management, Tickers, Stock Trading, FastAPI, Performance Tuning, WebSockets, Time Series Modeling, Image Generation, SOC 2( Service Organization Control), Mapbox SDK, Middleware, Jetpack Compose, Quantitative Analysis, Data Science, MVC Frameworks, Quarkus, Large Scale Distributed Systems, SSO Engineering, Technical Architecture, Technical Writing, Mobile Apps, Large-scale Projects, Social Security, IDP, API Connectors, Cloud Architecture, Airtable, PDF, Front-end, Team Leadership, Relational Database Services (RDS), SLAM, Simultaneous Localization & Mapping (SLAM), Dynamic Load Balancing, Plugins, System Security, LangChain, DDS, PDF Scraping, Midjourney, Strapi, Web3, Analysis, Dashboard, AI Website Builders, Buffer Management, ExpressIF, Bluetooth, ESP32, ACH Payments, Google Software, PayPal Development, Payment APIs, Smart Contract Development

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.

1

Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.
2

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.
3

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

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