Principle Software Engineer
2021 - PRESENTOracle- Developed a highly available, high performance and highly scalable REST API service in Oracle OCI using Go language in the back end to provide authorization service for internal client.
- Developed and maintained CI/CD pipelines build script to deploy REST API services in Kubernetes pods running in Oracle OCI and troubleshooting with Kubernetes CLI.
- Designed async API to support bulk operation for clients to import or upload huge amounts of data to our authorization service and stored data to Oracle DB.
Technologies: Go, Kubernetes, Oracle DBaaS, REST APIs, API Integration, SQL, APIs, Oracle PL/SQL, Oracle, Spring Boot, Object-oriented Programming (OOP), AutomationSenior Software Engineer
2020 - 2021JPMorgan Chase- 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 1000 TPS 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.
Technologies: Amazon Web Services (AWS), Performance, Spring 5, Postman, JSON, Web API, Design Patterns, HTTP REST, JavaScript, Node.js, Back-end, REST APIs, Apache JMeter, Cassandra, Jenkins, Python, Java, XML, SQL, Bootstrap, Spring Boot, Apache Kafka, Object-oriented Programming (OOP), ReactSenior Software Engineer
2019 - 2020P97- 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 ensure zero downtime during app service deployment, web jobs, azure functions, etc.
- Created web jobs in Azure to communicate with different payment hosts by different payment types, such as Google Pay, Apple Pay, Samsung Pay, or Chase Pay.
- 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#. An LRU cache 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 to finish payment workflow. Each web job will be a consumer and 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.
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 (OSB), Service, Azure Cosmos DB, C#, ASP.NET, XML, XML Parsing, Fintech, REST APIs, API Integration, SQL, APIs, Bootstrap, Azure, Object-oriented Programming (OOP), C#.NETDeveloper
2019 - 2019Palmetto Wood Shop, LLC (via Toptal)- Extracted Excel data and processed it using VBA script.
- Utilized CorelDRAW API to automate interaction with CorelDRAW UI. Integrated CorelDRAW and ShipStation.
- Used hashmaps, collections, arrays, and data structures to process and convert data from ShipStation to CorelDRAW.
Technologies: CorelDRAW, Microsoft Excel, Visual Basic for Applications (VBA), CSSSenior Software Engineer
2007 - 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.
- Worked as a full-stack developer to create REST API with Java and Node.js/JavaScript to support real-time monitoring and alarm. Created a service that provides a good view about healthy status of all apps running in either cloud or desktop.
- 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.
Technologies: Performance, Software Architecture, MySQL, Web API, TFS, Google Test, Standard Template Library (STL), Design Patterns, IIS, JavaScript, .NET, JSON, Windows Presentation Foundation (WPF), ASP.NET, Moq, Docker, Microsoft SQL Server, COM, Python, Node.js, Java, C++, C#, Visual Studio, XML, XML Parsing, APIs, Azure, .NET Core, Object-oriented Programming (OOP), C#.NET, Automation, ReactSenior Software Developer
2004 - 2007Nortel Networks- 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/Linux commands and Bash shell as a small tool in daily development.
- 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.
Technologies: Eclipse IDE, IBM Rational Rose, Unix Shell Scripting, Design Patterns, Solaris, C++, Java, Software Development, Oracle PL/SQL, .NET Core, Object-oriented Programming (OOP)Senior Software Developer
2001 - 2004HInnovation- Designed MySQL database tables and developed stored procedures to support a medical remote diagnostic system.
- Developed ASP web pages with JavaScript to provide query and statistic function.
- 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.
Technologies: MySQL, Standard Template Library (STL), IIS, C++, JavaScript, ASP.NET, Software Development, Object-oriented Programming (OOP)