John Brant has 20 years of program restructuring/refactoring experience. He is the co-author of the Smalltalk Refactoring Browser, the first widely-used refactoring environment for any computer language. He has consulted on several very large migration projects. Many projects were migrating Visual Smalltalk Enterprise-to-VisualAge Smalltalk and VisualAge Smalltalk-to-Java. He also migrated C with embedded SQL-to-Java, VisualAge Java-to-EGL, and Delphi-to-C#. The Delphi-to-C# migration project was described in an experience report at the 2010 International Conference on Software Maintenance. Some of the companies that he has performed these migration projects for include Misys, Sempra Energy, Jack Henry, American Express Financial Advisors, and Cefetra.

In addition to migration projects he has also developed sales forecasting and accounting software using Oracle and Microsoft Access for North American Lighting, an automotive supply company. Additionally, John worked on a couple of Adaptive systems for Iron Mountain Fulfillment Services which included a dynamic invoicing systems and an adaptive system for describing and importing data from clients which included core ETL and a domain specific language for describing the integration rules.