Software does not age well. Often a piece of software starts out with a crisp well-defined vision and a clear distinct architecture, then expedient changes are made and the original clear vision is quickly lost. Software ages rapidly becoming rigid and fragile. Simple changes take excessively long to implement and are frequently unreliable. This seminar will present the concept of refactoring. Refactoring is a collection of techniques for rejuvenating software by improving the structure and performance of existing software without changing the behaviour of the software.