js 함수형 프로그래밍
https://www.inflearn.com/course/%ED%95%A8%EC%88%98%ED%98%95-%ED%94%84%EB%A1%9C%EA%B7%B8%EB%9E%98%EB%B0%8D
node.js express API server + UUID api-key
https://youtu.be/8XpVJaEWesM
자바스크립트 초급 / 중급 문법
https://www.youtube.com/watch?v=KF6t61yuPCY
https://www.youtube.com/watch?v=4_WLS9Lj6n4
node js 백엔드 서버
https://www.youtube.com/watch?v=PkVV1OLaM5Q&list=PLSK4WsJ8JS4cQ-niGNum4bkK_THHOizTs&index=3
react + firebase
https://www.youtube.com/watch?v=DIc_nPKBrVA
