What is the KEY question that any data scientist should ALWAYS FOCUS ON?
It is “How can I solve Challenge X with data?”
Because any data scientist, in my opinion, are solution provider. Data Scientists are specialists looking at data and dig out any useful insights. Never about the fancy tools or the complex machine learning models that you used (,unless it makes commercial sense).
Thus a data scientist’s toolbox should be any tools that can assist the business to achieve its goals, with end-product possibly a decision, else insights that can lead to a useful solution.
Again keep in the mind, the question as a data scientist is “How can I solve Challenge X with data?”.
Consider supporting my work by buying me a "coffee" here. :)