Notes and assumptions to make it simple

• I didn't have any Django experience before (just FYI).
• Main app (app) and API (api) are implemented as two apps within one Django project.
• I didn't implement contacts paging.
• Everywhere I use built-in local-memory caching.
• I didn't care about Python 2.x compatibility.
• Images are proxified through API to enable caching and/or ability to replace the source.
• Requests to external sources and API are made directly from request handlers.

Questions to clarify

• No authentication (is it needed?).
• setup.py and other deployment things are missing.
• CSV file size is not checked.
• Image file size is not checked.
• Tests are missing.