I am part of a team of seven developers in a small software company and I am trying to introduce regular group code and design reviews. We have carried out some reviews in the past, but it has been sporadic. I would like to make it a more regular thing.

I have read Code Complete and other similar resources and they talk about the mechanics of how to carry out code reviews but I have been unable to find any best practices on how to choose what to review. We have a code base that is more than eight years old and covering a variety of languages, so there is plenty that could be looked at.

Here are some of the factors that I can think of that might affect the choice:

• Language: C, Java, SQL, PL/SQL
• Code age: New code vs old code
• Code usage: Frequently used code vs (effectively) dead/little used code
• Code importance: Critical code vs non-critical code
• Developer: Junior developer code vs Senior developer code

I understand that this isn't a question with an absolute definitive answer, but any guidance would be useful.

Some peripherally related questions:

• Code review approaches (Mentions of reviewing critical sections and new developer code)
• Should we attempt to review all our code?