While contributing to the MochaJS open source, I felt like I was always lacking because I didn't know much about Mocha, so I kept solving only simple issues. And I thought that even as a front-end developer, I should learn NodeJS someday. After taking this lecture, both of these were solved, and I think there was synergy between them. It's the best lecture I've taken from Inflearn, and I really recommend it. I want to meet the instructor once.