James Sun, Developer in Springfield, VA, United States
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James Sun

Verified Expert  in Engineering

Software Developer

Springfield, VA, United States
Toptal Member Since
June 18, 2020

James is a software developer with over 20 years of experience helping organizations solve complex database, reporting, and system integration issues. He has worked on a variety of platforms and databases—including Microsoft and LAMP stacks. James's ability to understand complex business processes, develop and document systems to manage those processes, and communicate technical information to non-technical people is what sets him apart from other technical resources.



Preferred Environment

Microsoft SQL Server, C#, Python 3, Microsoft Power BI, Tableau

The most amazing...

...and complex systems integration project is the one I am currently working on: it supports the processing of thousands of applicants to a major US university.

Work Experience


2017 - PRESENT
Law School in the Washington, D.C. area
  • Developed custom Cognos Analytics queries and reports that pull information from Banner, CourseLeaf, and Faculty Success.
  • Configured a GCE instance to run automated Python scripts to generate reports that are emailed to a Box-enabled email address.
  • Wrote Python scripts to synchronize and clean up faculty, course, and scheduled teaching data between multiple line-of-business systems, including Banner, CourseLeaf, and Faculty Success.
Technologies: Python, Cognos Analytics 11, SQLite, Microsoft SQL Server, XML, JSON, Google Compute Engine (GCE)


2010 - PRESENT
Casualty Actuarial Society
  • Developed a custom Microsoft Access application used for the CAS exam grading process. This is a semi-annual on-site process where society fellows gather from across the U.S. and Canada to grade essay exams submitted by prospective fellows.
  • Built a feature of the Access application that imports data from Microsoft Excel spreadsheets. The application also generates data that is imported into Excel as histograms.
  • Constructed Access reports that open custom forms used for gathering report parameters. Many reports have extensive report logic and complex grouping and sorting. Most reports are tabular, but some support multiple (newspaper) columns.
  • Attended semi-annual grading sessions and supported the in-person grading process.
Technologies: PDF, Microsoft Access

Senior Programmer and Analyst

2009 - PRESENT
Johns Hopkins University
  • Supported multiple functional areas—including registrar, admissions, and billing.
  • Developed custom SQL Server Reporting Services reports.
  • Built and maintained automated processes to integrate three applications from different vendors, including a web-based application, an internal document management system (with workflow), and the university's student information system.
  • Worked as the lead developer for our internal OnBase (Hyland) document management system.
  • Developed a Salesforce-based application to help manage walk-ins to our one-stop student services help desk.
  • Created and maintained Tableau and Power BI dashboards used by the internal Admissions staff to track and analyze applicants throughout the admissions cycle. All dashboards leverage multiple datastores stored in a data lake hosted in Microsoft SQL Server.
Technologies: OnBase, VB, C#, .NET, Microsoft SQL Server, Microsoft Power BI, Tableau, SQL Server Reporting Services (SSRS), T-SQL (Transact-SQL), SQL DML, Microsoft Excel


2008 - PRESENT
Agile Media Ventures, LLC
  • Implemented a redesign for the Americas Diabetes Challenge website. This site was hosted in WordPress and had both English and Spanish versions.
  • Maintained several custom public-facing PHP and MySQL websites. Several of the web applications included subscription and one-time payment processing using PayPal.
  • Updated the content for a leading e-learning portal for emergency room nurses. This was a custom application developed with PHP and MySQL.
  • Developed the Power-of-a-Hug website using WordPress along with a few off-the-shelf plugins, including a front-end uploader, justified image grid, and PODS.
  • Supported custom reporting engagements for a major provider of secure print management solutions. Developed custom reporting solutions using various tools—most notably SQL Server, Crystal Reports, and Tableau.
Technologies: MongoDB, Node.js, MySQL, PHP, WordPress, Microsoft SQL Server

Senior Data Engineer

2024 - 2024
  • Reviewed natural language queries and associated SQL statements for inclusion in the training data set for a custom LLM as part of a proof of concept.
  • Provided feedback on natural language queries developed by other SQL/data engineers. Reviewed and revised SQL statements written by other data engineers.
  • Analyzed publicly available datasets across a variety of domains hosted on Snowflake.
  • Created natural language queries to be processed by the custom LLM. Submitted natural language queries to the LLM. Reviewed SQL statements, fixed bugs, and refactored output from the LLM as part of the training process.
Technologies: SQL, English, Data Engineering, Query Optimization, Snowflake

Database Developer | Data Specialist

2022 - 2022
Norton LLC
  • Developed Python scripts to convert 80,000+ articles (XML files) from an existing CMS to WordPress.
  • Wrote Python scripts to transform existing pages with YouTube links into standalone pages on the new WordPress-powered website.
  • Developed Python scripts to transform existing pages with audio/MP3 links into standalone pages on the new WordPress-powered website.
Technologies: SQL, Databases, Data Migration, Data Cleansing, Data Cleaning, Python, XML, WordPress

Vice President for Software Development

1998 - 2008
American Technology Services, Inc.
  • Led teams that implemented multiple websites using various content management systems, including Ektron and DotNetNuke.
  • Managed the business development for the software development group, including writing proposals and presenting at trade shows and conferences.
  • Led the team that developed the Bechtel Public Affairs Database (BPAD)—a web-based tracking system used by the internal PR department at Bechtel.
  • Served as the chief technical architect for the development of the Enterprise Information System (EIS) for the Petroleum Finance Company.
  • Led the development of the CU Analyzer—an ASP.NET/SQL Server application that allowed external customers to analyze the relative performance of a credit union compared to its peers.
Technologies: DotNetNuke (DNN), Ektron CMS, Classic ASP, ASP.NET, VB, C#, Microsoft SQL Server, T-SQL (Transact-SQL), SQL DML

Sakura Matsui Festival

In 2012—when the Internet of Things (IoT) was barely in its infancy—I served as the lead software developer for a team that completed a demonstration of a real-time, pedestrian monitoring system at Sakura Matsuri, a major street festival in Washington, D.C. The project was paid for with a grant via the Reliability IDEA program administered by the Transportation Research Board. The IDEA program funded proposals with the potential to test innovative ways to improve the consistency or dependability of travel times, improve travel time prediction, and provide information to travelers and other highway system users when dealing with unexpected delays.

The technical architecture consisted of five key elements: Bluetooth sensors, data server, messaging server, data publishers, and information consumers. PubNub served as the primary messaging backbone for our technical architecture. I developed a simple specification for how all messages should be formatted throughout the application. Once committed to the spec, the team could integrate publishers and subscribers very easily across various locations, platforms, and technologies.

Automated Processes to the Support Admissions Cycle

I worked as the lead developer on a project integrating several different third-party web-based applications that support the admissions process at a leading U.S. graduate school. In addition to the day-to-day support of the various functional groups that use all three systems, I developed a series of automated tools and processes to integrate all three systems. The tools were developed using a variety of programs and languages (primarily on the Microsoft platform), including PowerShell, C# (custom command-line executables), SQL Server stored procedures (T-SQL), and Python.
1986 - 1990

Bachelor of Science Degree in Economics (Strategic Management)

University of Pennsylvania - Philadelphia, Pennsylvania, United States


jQuery, WordPress API, Node.js


Microsoft Access, Crystal Reports, Microsoft Power BI, Microsoft Excel, Ektron CMS, Tableau, Cognos Analytics 11, Google Compute Engine (GCE)


T-SQL (Transact-SQL), SQL, Python 3, Python, SQL DML, Snowflake, C#, VB, JavaScript, PHP, XML


SQL Server Reporting Services (SSRS), Microsoft SQL Server, MySQL, Databases, MongoDB, SQLite, JSON


OnBase, WordPress, DotNetNuke (DNN)


ETL, Business Intelligence (BI)


.NET, ASP.NET, Classic ASP, Windows PowerShell


Data Engineering, Data Migration, Data Cleansing, Data Cleaning, Data Transformation, PDF, Economics, Software Development, English, Query Optimization

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