Summary

In this chapter, we traveled back in time to 2009 to understand the creation of Node.js. After that, we realized why and when we should use the event-driven approach compared to a threaded model and the advantages it brings. We came to understand what evented, asynchronous code is and how JavaScript helped Node.js and Deno make the most out of the server's resources.

After that, we fast-forwarded through the Node.js' 10+ year story, its evolution, and how its adoption started. We observed how the runtime grew, together with its base language, JavaScript, while helping millions of businesses deliver great products to its clients.

Then, we took a modern look at Node.js, with today's eyes. What changed in the ecosystem and the language? What are some of the developers' pain points? We dived into these pain points and explored why it was difficult and slow to change Node.js to solve them.

As this chapter progressed, Deno's motivations became more and more evident. After looking at the past of JavaScript on the server, it made sense for something new to appear – something that would solve the pain experienced previously while keeping the things developers love.

Finally, we got to know Deno, which will be our friend for this book. We learned its vision, principles, and how it offers to solve certain problems. After having a sneak peek at the architecture and the components that made Deno possible, we couldn't finish without talking about some of the trade-offs and current limitations.

We concluded this chapter by listing use cases where Deno is an excellent fit. We will come back to these use cases later in this book, when we start coding. From this chapter on, our approach will be more concrete and practical, always moving toward code and examples you can run and explore.

Now that we understand what Deno is, we have all it takes to start using it. In the next chapter, we will set up the respective environment and write a Hello World application, among doing many other exciting things.

That's how exciting adventures start, right? Let's go!