# Siyi Liu

> Staff Software Engineer at Apple

Location: San Francisco Bay Area, United States
Profile: https://flows.cv/siyiliu

•	Over 13 years of strong programming experience in Java
•	Extensive expertise in developing and optimizing high-throughput, low-latency, large-scale services
•	Expert knowledge in microservice, spring boot, Jetty server and concurrent programming
•	Strong experience in production inference platform for machine learning models and variables
•	Hands-on experience with Spark, Scala, Hadoop, Hive, and related Big Data technologies

## Work Experience
### Staff Software Engineer @ Apple
Jan 2020 – Present | San Francisco Bay Area
Led server-side development with organization-wide impact for Apple apps, including News, Stocks, Weather
•	Designed, developed and maintained high-throughput, low-latency, and high availability, large-scale services to run A/B experiments and generate customized configurations for app users
•	Led discussion with product managers, cross-engineering teams, data scientists and other partners to gather requirements and translate them into technical specifications
•	Identified opportunities and led the entire development lifecycle end-to-end
•	Optimized service performance by investigating and addressing performance bottleneck, resulting in a 40% throughput increase and a 50% latency reduction
•	Conducted code reviews, mentored junior developers, and maintained high standard of coding best practice
Led the development and maintenance of Spark-based data analysis jobs, guaranteeing both high performance and data reliability
•	Collaborated with data scientists and implemented Spark jobs to process large-scale datasets
•	Optimized Spark jobs to enhance performance, minimize resource utilization, and reduce processing time

### Staff Software Engineer @ PayPal
Jan 2017 – Jan 2020 | San Jose
Worked on a large-scale web service that runs online machine learning models in the risk fraud detection team.
      • Designed and implemented large-scale high concurrent platform to catch fraud real time.
      • Proposed and designed new types of variables using asynchronous events, which reduced variable calculation time and improved service performance by 25%.
     • Investigated transaction datasets, proposed, and implemented a Spark-based tool to identify data issues at an early stage and expedite variable delivery. This solution received recognition with an innovation award.

### Senior Software Engineer @ PayPal
Jan 2015 – Jan 2017
Worked on certification projects for new product launch and platform migration.                             
      • Developed an offline tool using Java and Pig to compare shadow traffic with production traffic, resulting in a significant acceleration of launch and migration processes.

### Software Engineer @ PayPal
Jan 2013 – Jan 2015 | San Jose
Worked on Global Credit Expansion project in Risk team
      • Created Credit Fraud Analytics Service from scratch in Java 
      • Implemented unit test cases by using PowerMock framework, achieved 100% code coverage

### Software Engineer @ Apptera, Inc
Jan 2011 – Jan 2013
Worked as a full-stack software engineer on server-side and android client-side for application, Raved.


## Education
### Master of Science in Computer Science
University of Massachusetts Boston (UMass Boston)

### Master of Science in Management Science and Engineering
University of Science and Technology Beijing, China

### Bachelor of Science in Information Management and Information System
University of Science and Technology Beijing, China


## Contact & Social
- LinkedIn: https://linkedin.com/in/siyiliu

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Source: https://flows.cv/siyiliu
JSON Resume: https://flows.cv/siyiliu/resume.json
Last updated: 2026-04-12