This is a basic proof-of-work blockchain and cryptocurrency application built using node, express and redis with a minimal UI built with react. Two instances of the app are live at https://thawing-mountain-05200.herokuapp.com/ and https://guarded-beyond-51860.herokuapp.com/ which can sync transactions with each other through their shared redis connection which acts as an event bus.
https://www.youtube.com/watch?v=bBC-nXj3Ng4 -> 3Blue1Brown proof-of-work based cryptocurrency video