Get started with functional programming in JS through this  series of explainers & interactive exercises. 

To access the full workshop, including video lessons, join FrontendMasters: frontendmasters.com/workshops/functional-first-steps

Anjana Vakil

Functional JavaScript First Steps

Oh no!  Getting "Sorry, we couldn’t find that page." on https://observablehq.com/@anjana/recursion

Aaron Kyle Dennis

Ah thanks for flagging, fixed the link! All the materials can also be found in the collection: https://observablehq.com/collection/@anjana/functional-javascript-first-steps