# siyuan he

> Lifetime Software Engineer

Location: Danville, California, United States
Profile: https://flows.cv/siyuanhe

Highlight: 15 years of experience in designing/building/operating large scale distributed systems Languages: Core Java, Scala, SQL,
Frameworks: Spring Cloud, Spark, Temporal
Data Store/Message Queue: MySQL, Cassandra, Kafka, HBase, TiDB
Infrastructure/IaC: AWS, Kubernetes, Terraform, Ansible

## Work Experience
### Software Engineer @ Plaid
Jan 2025 – Present | San Francisco Bay Area

### Engineering Manager @ TikTok
Jan 2024 – Jan 2025

### Sr. Engineering Manager @ Paytm Labs
Jan 2021 – Jan 2024 | Toronto, Ontario, Canada
•Led cross-functional teams (SRE/Platform/DevOps 20+ team members) to build and operate a large scale Risk system, enabling real-time fraud detection for 100M+ monthly active users, handling 10K+ TPS during peak hours
• Design and implemented of a state-of-the-art ML feature store supporting real-time and batch data processing, which can process billions of real-time events daily and 100+ PB batch data.
• Improved p99 of fraud check requests from 100ms to 15 ms in peak hours
• Introduced Operational Excellence process to improve system reliability from 99.9% to 99.99%
• Tech Stack: AWS/Kubernetes/Terraform/Ansible/Spark/Temporal/EMR

### Engineering Manager @ Paytm Labs
Jan 2020 – Jan 2021 | Toronto, Ontario, Canada
• Led cross functioning team (SRE/Backend/Data Engineer)to build an advertising platform for paytm India.
• Worked with product/sales/business operations to prioritize product features and was able to generate 1 million USD per month within 1 year after launch of the business.
• Tech Stack: Spring Cloud/Kubernetes/Kafka/AWS/MySQL/Spark/BigQuery/Terraform

### Technical Lead @ Paytm Labs
Jan 2016 – Jan 2020 | Toronto, Ontario, Canada
• Led a team (Backend and SRE) to develop a payment system to support Paytm Canada’s business, including bill payments and merchant acquiring.
• Took only two months to build a PCI-DSS compliance system to store and process user credit cards/bank accounts.
• Led a team (Backend and SRE) across Canada/Japan/India to build the core payment system for PayPay (www.paypay.com top 1 payment app in Japan) in 3 months.
• Scaled the system to support 30 million+ users/1 million+ merchants/1000+ payment TPS.
• Tech Stack: Spring Cloud/Kubernetes/Kafka/AWS/MySQL/Kafka/TiDB

### Platform Engineer @ Paytm Labs
Jan 2015 – Jan 2016 | Toronto, Ontario, Canada
• Designed/Developed a real-time fraud detection engine capable of evaluating 100+ risk rules within 60ms at p99.
• Tech stack: Akka/Scala/Cassandra. (check detail at this https://www.slideshare.net/jparkie/developing-a-realtime-engine-with-akka-cassandra-and-spray-51902586)

### Hadoop Engineer @ Sysomos
Jan 2014 – Jan 2015
Part of infrastructure team to built/maintained/operated a big data processing pipeline to analyze social media data, including Twitter, Facebook and Tumblr and etc.
-Tech stack: HDFS+YARN+HBase+Solr+Kafka+Spark
-The whole cluster contains 200+ servers and stores 300T+ data.
-Performed JVM tuning to improve the stability and performance of cluster.
-Worked with Data scientists teams to develop distributed data mining algorithms on spark
-Applied Puppet for deployment automation and Nagios for system-level monitoring
-Capacity Planning/Estimation for Solr and HBase cluster

### Senior Software Engineer @ SiteScout (Centro.net)
Jan 2014 – Jan 2014 | Tornto
-Improve/Maintenance the current real-time bidding platform that can handle 30B impressions daily.
-Design and Develop a large-scale real time big data processing platform for machine learning and SQL-like processing based on Lambda architecture.
-Work closely with a Data Scientist to transfer his local version of machine learning algorithm to distributed version using Apache Spark(Spark Core + Spark Streaming)
-Tech stack: Core Java/Servlet + Apache Spark+ Kafka + HBase/HDFS + Aerospike.

### Senior Java Developer @ Citi
Jan 2012 – Jan 2014 | mississauga
- Developed/Maintained messaging systems using Hadoop/HBase/Tibco ems.
- Performance JVM/HBase tuning to improve read/write performance under heavy load
- Analyzed/Identified system performance issues/bottleneck and provide relevant solutions
- Integrated Phoenix (https://github.com/forcedotcom/phoenix) to the current system to support SQL over HBase
- Developed messaging system using Kafka to replace Ticbo brokers to make the current system more stable and scalable.

### Java Developer @ MaintenanceAssistants.com
Jan 2011 – Jan 2012 | Toronto
-Designed/ co-architected/migrated the existing single-tenant system to be a high-availability, scalable multi-tenanted SAAS platform.
-Set up production/staging environment based on Amazon Virtual Private Cloud.
-Designed/ co-architected an internal CRM system to facilitate business operation.
-Main Technology Stacks: Play! Framework, Spring, Hiberante, Rails, jQuery, Emberjs, MySQL.

### Java Developer @ Healthscreen Solution
Jan 2011 – Jan 2011
-Co-Designed/Developed a Distributed Data Synchronization sub-system between clients’ database and company’s central database to facilitate data pulsing and retrieving process.

### Software Developer @ www.taobao.com
Jan 2010 – Jan 2010
-Designed/Developed a code coverage tool for testing distributed systems.
-Collaborated with the configuration management team to integrate a code coverage tool into test environment
-Hacked into the source code and architecture of EMMA(emma.sourceforge.net) 
-Extended EMMA to 1) monitor system testing code coverage for distributed systems, which run within Jboss; 2) detect code changes at method level;3) support branch coverage;
-Stack: HttpClient+MySQL+Jetty


## Education
### Master of Applied Science in Software Engineering
Carleton University


## Contact & Social
- LinkedIn: https://linkedin.com/in/siyuan-he-548b3013

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Source: https://flows.cv/siyuanhe
JSON Resume: https://flows.cv/siyuanhe/resume.json
Last updated: 2026-04-11