# Synchronization > ## Lean software development ## [Lean software development](https://wiki.g15e.com/pages/Lean%20software%20development.txt) [LSD](https://wiki.g15e.com/pages/Lean%20software%20development.txt)의 원칙 중 하나인 [Amplify learning](https://wiki.g15e.com/pages/Amplify%20learning.txt)의 도구. > Whenever several individuals are working on the same thing, a need for synchronization occurs. So in , synchronizing the seveal people working on a feature is necessary, while common code ownership (see ) requires that several people working on the same piece of code must be synchronized. The need for synchronization is fundamental to any complex development process. --p35 Spanning application: > Another way to synchronize the work of several teams is to start by having a small advance team develop a simple Spanning Application through the system. … > > There are several different names used for a Spanning Application. … call the same concept a tracer bullet. uses the term "walking skeleton", and , in , calls it a spike. In , , a spike is an experiment to validate an estimate. --p36