Senior Software Engineer2020 - PRESENTA Company in the Financial Industry
- Provided a scalable, highly available, and low latency data transformation web service in a public and private cloud with a Java back end.
- Worked on performance enhancement and troubleshooting to better support more than 1000TPS during peak time.
- Built-up a CI/CD pipeline to generate metrics data for every build, unit test/integration test execution, deployment, and more. Also, achieved zero downtime during every deployment.
Senior Software Engineer2019 - PRESENTP97
Technologies: Software Architecture, Postman, JSON, ASP.NET Core 2, Moq, TFS, Chase Paymentech, ISO 8583, Worldpay, Google Pay, Microsoft SQL Server, .NET Core, .NET, Visual Studio, Oracle Service Bus, Service, Azure Cosmos DB, C#, ASP.NET
- Developed a web service for a mobile payments app in .NET/.Net Core, and C# running in Azure. Utilized SQL Server DB, Azure Cosmos DB, Redis Cache, and In-memory cache as a data storage strategy to achieve the best performance.
- Applied the blue-green deployment strategy in Azure to make sure zero downtime during deployment of app service, web jobs, azure function, etc.
- Created web jobs in Azure to communicate with different payment hosts by different payment type, such as Google Pay, Apple Pay, Samsung Pay, or Chasepay.
- Used C# to create a new payment workflow with Worldpay. Got payment info from the Service Bus topic and packed them into ISO 8583 message format, sent to WorldPay server, and returned transaction result as Service Bus message.
- Implemented in-memory cache with TTL in C#. It is a LRU cache that can get data from SQL Server and Cosmos DB. It also supports REST API to access the cache.
- Used Service Bus to support event-driven workflow to combine different web jobs together to finish payment workflow. Each web job will act as consumer and/or producer of a specific Service Bus message.
- Worked on a data analysis project which tries to gather performance metrics data by different payment workflows. Data came from Cosmos DB with indexes created to get better performance.
Developer2019 - 2019Palmetto Wood Shop, LLC (via Toptal)
Technologies: CorelDRAW, Microsoft Excel, Visual Basic for Applications (VBA)
- Integrated CorelDRAW and ShipStation.
- Extracted Excel data and processed it using VBA.
- Utilized CorelDRAW API to automate interaction with CorelDRAW UI.
- Used hashmaps, collections and arrays, etc. data structures to process and convert data from ShipStation to CorelDRAW.
Senior Software Engineer2007 - 2019Schlumberger
- Redesigned data structure, re-architected software, and introduced parallel programming in back end to improve the performance of web services and desktop apps. Improved performance from 30%-80% in large scale real tie acquisition system.
- Set up the CI system to improve development efficiency for a large population of the community. Improved the development life cycle time from 3-7 hours to 10-60 minutes which save a lot of money for the projects.
- Worked as one of the authors to write C++ and C# coding standards for projects. Around 150 developers all over the world followed this coding standard in daily work and code review session.
- Created web service to host an automatic log file analysis and dump file analysis. Promoted the project troubleshooting and monitoring to higher level and saved a lot of money for the project.
- Introduced the static code analysis tool Coverity to project for C++, C# and Java. Has been integrated to CI system in 2009 and still acts as one of the most important metrics data to measure code quality.
- Implemented tool control system via Socket in C++. Controled behavior of hardware by sending a command to hardware and it also read messages sent from hardware to know the real-time status of hardware.
- Used Amazon Lambda to host a small web service to maintain hardware inventory info. Compared Lambda and EC2 and chose Lambda by its lower cost and fast deployment. Done in Java.
Senior Software Developer2004 - 2007Nortel Networks
Technologies: Eclipse IDE, Rational Rose, Unix Shell Scripting, Design Patterns, Solaris, C++, Java, Software Development
- Designed an Oracle database and developed stored procedures.
- Programmed in Java to add new features for the network and telecommunication device management system.
- Utilized Solaris commands and bash shell.
- Programmed in C++ to create an interface between hardware and the Java application.
- Used Eclipse as an IDE to do the coding work for C++ and Java.
Senior Software Developer2001 - 2004HInnovation
- Designed MySQL database tables and developed stored procedures to support a medical remote diagnostic system.
- Developed COM objects as back-end or business logic layer in C++. Those COM objects acted as a small service to combine the whole workflow together.
- Created IP phone functionality based on the H.323 protocol. Integrated with high efficient compression and decompression algorithm. Also integrated with the echo elimination algorithm.
- Created a C++ program based on different medical image formats such as CT and MRI.
- Created automatically fax module by integrating it with hardware in C++. Converted a text into a TIFF format file, sent it to hardware, and to the target fax machine.