Wenfei Liang

• Design and implement Google Pay and Apple Pay Gateway RESTful APIs using C# 10 and .NET 6; collaborate with other teams to release the project to Production.
• Develop administration web portals ROAMsupport and ROAMmerchant(MCM6) using Angular, Typescript, Spring MVC. Take the lead for multiple projects and manage contract team for the implementation.
• Implement critical RESTful API features (MCM6) including Webhook, Billing Package Management, Reset Password, User Management, Risk Check, Configuration Management, Customer Boarding, etc. using C#, SQL Server.
• Collaborate with Gateway and Mobile teams to implement mPOS EMV SDK for ISVs and developers.
• Manage Transaction related Data Schemas and Stored Procedures using SQL Server.
• Monitor/optimize the performance of Transactions API using Jmeter.
• Develop administration web portals ROAMsupport and ROAMmerchant(MCM5) using Spring MVC, jQuery.

• Processed data using Hadoop, Hive, HBase, BigQuery on EC2/google cloud platform.
• Analyzed and visualized data using Pandas, Matplotlib, Numpy, Scikit-learn, NLTK, IPython with algorithms of Naïve Bayes, K-means, DBSCAN, Affinity Propagation.
• Scraped and stored data from website using Scrapy, PostgreSQL, SQLAlchemy.
• Created shell scripts and run sequential workflow with command line tools including s3cmd, bq, gsutil on Ubuntu.

Enhanced Data Analysis Tool (Web application)

• Implemented changes, fixes and new features to the web application using Ruby on Rails.
• Rebuilt and condensed code by 70% by abstracting similar logic in previous code.
• Fixed dozens of bugs of previous code and improved performance by 90% on running analysis.
• Implemented data visualization feature using javascript library of Jsplumb.
• Implemented features of exporting tables into one zip/csv file; reduced 90% of download time.

• Designed database structure, core modules using Power Designer, SQL Server.
• Implemented core modules with methods of pair programming and test-driven development using Java.
• Created core module used for importing data from Excel files using Java, JavaScript.
• Led, planned and supervised test procedure using TestDirector, LoadRunner.
• Deployed and maintained the system in Linux OS and managed data on SQL Server database.