One of the big wins is being REPL/workbook-focused, rather than REPL/workbook as an afterthought. When I'm building software, I tend to like things to have ver

One of the big wins is being REPL/workbook-focused, rather than REPL/workbook as an afterthought. When I'm building software, I tend to like things to have very tight interfaces -- box everything up into components, understand how they talk to each other, etc. Define interfaces, implementations, types, etc -- In general, optimizing for long-term maintainability. When I'm exploring data, my thought process is much more "scatter everything about on the desk" and "let me run these 5 lines of code again within the current context". "What does this thing look like", etc. Having "a table of data" as a first-class citizen in the language, with all the libraries assuming that as input and everything optimized to work around / display / visualize such is incredibly useful.