I've loved Python since I took 6.01 (Intro EECS). We used it at MIT for research, for homework, and for doing Matlab work without Matlab, and I've used it since for my scripts and projects. I was a Lab Assistant for 6.01 and 6.02 (Intro EECS II), and I helped teach an Intro to Python class during our January period. I am a part of InfoScout's Insights team since Feb 2017, which means working with Django, Celery, SQLAlchemy and pandas.
I've worked with Java since 2011, when I took 6.005 (I used Eclipse and hated it). After college, I worked on the ADF Shared Components (ADFShare) team at Oracle from July 2013 until January 2017. We used (and developed components for) JDeveloper; one of my first projects at Oracle was adding internal static-member audits to JDeveloper. I have my qualms about Java, but Java 8 looks promising, with type annotations, lambda expressions and method references.