Refactoring to a S.O.L.I.D. Foundation


In this session we take a small, functional but tightly-coupled, software solution and improve its design using each of Robert C. Martin’s S.O.L.I.D. principles as follows:

  • SRP: Single Responsibility Principle
  • OCP: Open-Close Principle
  • LSP: Liskov Substitution Principle
  • ISP: Interface Segregation Principle
  • DIP: Dependency Inversion Principle

Each principle is applied in sequence to the existing solution, making it possible for the attendee to observe the principle in relative isolation first while also evolving an understanding of how the principles all collaboratively reinforce each other when applied together.

Before each principle is applied and the solution is refactored to introduce it, the attendee is presented with one or two simple PowerPoint slides to introduce the concept and provide some abstract understanding of its goals and benefits to OO programming. The principle is then applied to the existing solution, demonstrating the practical application of the principle to working software.

At each step along the way, the existing solution (a simple console application) is re-executed, demonstrating that the overall behavior of the software solution has not been negatively impacted by the various refactorings.

Stephen Bohlen

Currently a Principal Software Engineer for the Technology, Evangelism, and Development (TED) Team within Microsoft Corporation, Stephen brings his varied 20-plus-years of experience as a former practicing Architect, CAD Manager, IT Technologist, Software Engineer, CTO, and consultant to assist select Microsoft Partner organizations in their adoption of cutting-edge and pre-release Microsoft developer products and technologies.

Stephen is also an active contributor to several Open-Source Software projects including NHibernate, Spring.NET, Common.Logging, NDbUnit, Common.Logging, and others.

Active in the software development community, Stephen speaks publicly, blogs (semi-)regularly, and is the author of several popular screencast series focused on Agile and ALT.NET concepts and technologies including the widely-praised 15-part Summer of NHibernate video series introducing viewers to the popular open-source O/RM tool.  Stephen is also a founding/organizing member of the NYC ALT.NET user group as well as a co-organizer of the New York City Domain Driven Design User Group.  For the past several years, he has been the Chairperson of the annual New York City Code Camp event.  He has also been a Microsoft MVP award recipient in Solution Architecture, ASP.NET, and Visual C#, a member of the ASP Insiders and the Visual C# Insiders, and formerly held the office of the Vice President for INETA, North America.