If you get in much deeper than just a couple of functions, I highly recommend using Middy. It acts as a ‘sort of’ middleware, which makes it much easier to write reusable stuff and comes with its own often-used middleware, such as converting the body from JSON to an object.
generally Lambda in programming languages has been another word for anonymous functions, and has been for decades, until Amazon decided it'd be fun to name a product after a general programming concept.
https://github.com/middyjs/middy
We have over 40 functions on our main product and it’s been working really well.