David Heinemeier Hansson (DHH)

Our brains are configured differently.

My brain is configured perfectly for Ruby, perfectly for a dynamically duck-typed language that I can chisel code out of a text editor with.

And other people need the security of an IDE.

They want the security of classes that won't compile unless you call the methods on it.

I have come to accept that, but most programmers don't.

They're still stuck in essentially, I like static typing.

Therefore, static typing is the only way to create reliable, correct systems, which is just such a mind-blowing thing.

to be blunt, idiotic thing to say in the face of evidence, mountains of evidence to the contrary.

This is one of the reasons I'm so in love with Shopify as the flagship application for Ruby on Rails.

Shopify exists at a scale that most programmers will never touch.

On Black Friday, I think Shopify did 1 million requests per second.

That's not 1 million requests of images.

That's of dynamic requests that are funneling through the pipeline of commerce.

I mean, Shopify runs something like 30% of all e-commerce stores on the damn internet.

A huge portion of all commerce in total runs through Shopify, and that runs on Ruby on Rails.

So Ruby on Rails is able to scale up to that level without using

static typing in all of what it does.

Now, I know they've done certain experiments in certain ways because they are hitting some of the limits that you will hit with dynamic typing.

And some of those limits you hit with dynamic typing are actually, by the way, just limits you hit when you write 5 million lines of code.

I think the Shopify monolith is about 5 million lines of code.