It all started out so simple, but somewhere along the line your web app turned into a beast. How do you keep it under control as it expands across multiple machines, multiple versions, and client customizations?

This talk will examine how open source tools were used to manage a large, modern, Perl web application through three years of major growth and change. Topics will include:

• Leveraging version control and branching strategies.
• Managing large sets of CPAN modules, some with local changes.
• Creating an automated build system.
• Testing strategies for a complicated database application and a modern web UI.
• Automating data migration during upgrades.
• Isolating client-specific changes from core code with a plugin system.

We'll talk about worked, where the common wisdom failed us, and what practical lessons you can take from our experience.