Greetings,
I am a full-stack Python developer, and I am familiar with scientific data processing / visualization with Python.
There exist a diversity of different techniques for implementing a web application with apache + python + mysql, from the simplest (and somewhat inefficient) Python CGI, to apache's mod_python, to modern Python WSGI. Before accepting the project, I would require the employer to elaborate the preferred Python web technology to use.
Same choice goes with Python-based plotting. PyGnuplot is a viable approach, but it is not quite suitable for use in a backend service. With the employer's consent, I would propose to use an alternative (and more popular) python package for plotting the data. And it yields more efficiency and more seamless integration into the python backend.
Feel free to contact me via private messages to discuss.