For integrated services, it makes sense to keep several logical Python projects in a single repository -- a common library, a web front end and a back end service. For such repositories, Pants (build in Python for Python, Java, C++ and more) helps maintain dependencies and build (mostly) stand-alone executables which simplify deployment. Abstract Pants is a modern build system written in Python. It can build Python, Java, C++, Go and more. Twitter, Square and FourSquare use it internally, and contribute to it.
Bio: Moshe is a Twisted contributor, and has contributed to core Python. He loves infrastructure for building, monitoring and making services highly available.