Bill is available for hire

Bill Yang

Verified Expert in Engineering

Database Analytics Developer

New York, NY, United States

Toptal member since January 17, 2017

Expertise

SQL JavaScript C#Elasticsearch Python NoSQL C++Git Node.js

Bio

Bill is an expert in large-scale distributed systems and data analytics, with a wide range of experience ranging from web startups to consulting and enterprise to some of the biggest names in tech. Some of his work became part of the backbone supporting platforms like DoorDash and YouTube.

Portfolio

Google

C++, Database Analytics

DoorDash

Python

TuneIn

C#, SQL

Experience

SQL - 10 years
C# - 8 years
Database Analytics - 6 years
Distributed Systems - 5 years
NoSQL - 3 years
Python - 3 years
C++ - 2 years
Node.js - 2 years

Availability

Part-time

Preferred Environment

Node.js, Python, C++, C#

The most amazing...

...project I've built is a dynamic delivery fee model while working at DoorDash, that increased the company's revenue by 5% —around 100 million at the time.

Work Experience

Senior Software Engineer

2021 - 2023

Google

Worked on a database query engine powering YouTube Analytics, one of the largest analytics databases on the planet, to the tune of multiple exabytes.
Improved predictability of query performance and overall system utilization by introducing dynamic throughput management to the query engine.
Introduced automatic client usage attribution, which helps the company better manage its compute budget.

Technologies: C++, Database Analytics

Senior Software Engineer | Tech Lead

2019 - 2020

DoorDash

Led a cross functional team to expand restaurant availability via dynamic delivery fees, which ultimately led to a 5% or over $100 million increase in revenue by the end of 2020.
Worked closely with several other technical leads to design our new microservice architecture and resolve cross-team architectural issues.
Led several technical projects extracting various pricing logic from our Python and Django monolith into a new Kotlin and Kassandra-based service, forming a new engineering team around this new domain in the process.
Led several other pricing-related projects to support more flexible pricing adjustment for both driving volume and response to regulatory changes.

Technologies: Python

Senior Software Engineer

2017 - 2019

TuneIn

Took part of the team responsible for the majority of our core back-end platform, including systems powering homepage, search, player, and other content-related functions.
Led a project from ideation, getting support to completion to improve homepage recommendations, resulting in a 3% increase in conversion.
Investigated and mitigated distributed hacking attempts.

Technologies: C#, SQL

Lead Developer

2016 - 2016

Clevertech

Created a message-processing system that can scale to millions of messages per day.
Migrated our message queue technology from Azure MQ to Amazon SQS.
Worked on a related front-end application based on React and Electron.

Technologies: Node.js, JavaScript

Senior Developer

2013 - 2016

Alberta Ministry of Education

Developed a curriculum development application using Angular, C#/.NET, and SQL Server.
Resolved various performance issues—primarily related to search and querying complex data.
Participated in the Agile transformation of the team and the department.

Technologies: JavaScript, C#

Solution Consultant

2010 - 2013

DevFacto Technologies

Delivered consistently successful software projects, sometimes under pressure.
Provided technical advice to the clientc.
Advocated engineering best practices like Agile to client teams.

Technologies: JavaScript, Git, SQL, C#

Software Developer

2008 - 2010

Upside Software

Developed new features and maintained the existing code base with a million lines of code.
Provided technical support to implementation teams.

Technologies: JavaScript, SQL, C#

Programmer

2007 - 2008

Idea Market Design Inc.

Developed new websites in the Joomla! Framework.
Managed the Linux servers at the company and for some of our clients as well.
Worked on a data gathering/processing initiative.

Technologies: SQL

Programmer

2005 - 2006

Seneca College

Patched an open source network tool for a specific security problem that we faced.
Developed a project management website.
Managed server farms and wrote the corresponding documentation for them.

Technologies: SQL

Experience

Time Tracker

The time-entry application is designed with a straightforward approach, utilizing Angular for the front-end development, Node.js to power the REST API, and MongoDB to ensure efficient data persistence and storage. This combination of technologies enables seamless time tracking and management capabilities.

Curriculum Development Application

I worked with a cross-functional team to develop an application digitizing curriculum development process. I was involved in all parts of the development process, and my main contributions included:
- Improving performance of a very complex search functionality.
- Creating a separate public-facing application to allow staged content publishing and a higher-performance consumer app.
- Modifying a TinyMCE editor to support math symbols.

Main technologies used: C#, AngularJS, SQL Server.

Shipping Middleware

I led a team to develop a centralized back-end system for a shipping company. The system is made up of a collection of microservices written in Node.js and acts as a distribution center linking other applications and databases.

My primary contributions include:
- Scaling the system to handle millions of messages per day.
- Migrating our message queue technology from Azure MQ to Amazon SQS.
- Tune-logging to find the optimal point for debugging and performance.
- Diagnosing some product issues under pressure.
- Mentoring other developers on the team.
- Managed client inquiries and requirement changes.

Main technologies used: Node.js, Microservices, Azure Message Queue, AWS SQS.

Google AI Challenge | Ants

https://github.com/analyst74/aichallenge-ants

Developed a game bot to compete in an AI challenge sponsored by Google and ranked 57 out of 8,000+ participants.

Main technologies used: Python, Numpy, Cython, Algorithms Design.

Soccer Field Search

https://github.com/analyst74/rec-search

A simple tool to search for soccer fields in Toronto using a dataset from the Toronto government's open data website.

Main technologies used: Node.js, MongoDB.

Construction Document Management System

Helped build a document management tool for PCL—a large construction firm to share documents between different branches and on-site workers.

Main technologies used: C#, SharePoint.

Upside Contract

I worked on a large enterprise contract management system with a wide variety of functionalities resolving around contract creation and management.

Main technologies used: C#, SQL Server.

Education

2003 - 2006

Diploma Degree in Computer Programming and Analysis

Seneca College - Toronto, Canada

Skills

Libraries/APIs

Node.js

Tools

Git

Languages

SQL, Python, C#, JavaScript, C++

Storage

Elasticsearch, NoSQL

Paradigms

Microservices Architecture, Concurrent Programming

Other

Distributed Systems, Database Analytics

Collaboration That Works

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