Happy New Year! It’s time to review the big trends in JavaScript and technology in 2020 and consider our momentum going into 2021.

Our aim is to highlight the learning topics and technologies with the highest potential job ROI. This is not about which ones are best, but which ones have the most potential to land you (or keep you in) a great job in 2021. We’ll also look at some larger tech trends towards the end.

Language Rankings

JavaScript still reigns supreme on GitHub and Stack Overflow. Tip #1: Learn JavaScript, and in particular, learn functional programming in JavaScript. …

React is the world’s most popular JavaScript framework, but it’s not cool because it’s popular. It’s popular because it’s cool. Most React introductions jump right into showing you examples of how to use React, and skip the “why”.

That’s cool. If you want to jump in and start playing with React right away, the official documentation has lots of resources to help you get started.

This post is for people who want an answer to the questions, “why React? Why does React work the way it works? What is the purpose of the API designs?”

Why React?

Life is simpler when UI components are unaware of the network, business logic, or app state. Given the same props, always render the same data. …

Is there a shortcut to becoming a 10x developer? Is there some magical secret that — if you only knew it — would unlock a whole new world of software development mastery and productivity for you?

This is where the doubters are thinking “There are no shortcuts! Everybody needs to practice to get good!” And that’s true enough, but what are the experts of software productivity practicing, and is there one key thing that can make a huge difference?

Yes! There is!

But even if I share it with you — even if I give it away and spell it out for you in detail— it might take you 10 years to grow into and fully appreciate the simplicity of it. …

Redux is an amazing tool if you take the time to get to know it. One of the things about Redux that commonly trips people up is that reducers must be pure functions.

A pure function is a function which:

1. Given same arguments, always returns the same result, and
2. Has no side-effects (e.g., it won’t mutate its input arguments).

The problem is that sometimes a reducer needs to make a complicated change to some input state, but you can’t just mutate the state argument without causing bugs.

The solution is a handy tool called Immer. In this video, I’ll introduce you to Immer and show you how to use it to reduce the complexity of your reducer code. With one or two small reducers, the difference is pretty subtle, but on a large project, it can significantly simplify your application code. …

Note: This is part of the “Composing Software” series (now a book!) on learning functional programming and compositional software techniques in JavaScriptES6+ from the ground up. Stay tuned. There’s a lot more of this to come!
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Abstract Data Types

Not to be confused with:

Algebraic Data Types (sometimes abbreviated ADT or AlgDT). Algebraic Data Types refer to complex types in programming languages (e.g., Rust, Haskell, F#) that display some properties of specific algebraic structures. e.g., sum types and product types.

Algebraic Structures. Algebraic structures are studied and applied from abstract algebra, which, like ADTs, are also commonly specified in terms of algebraic descriptions of axioms, but applicable far outside the world of computers and code. An algebraic structure can exist that is impossible to model in software completely. For contrast, Abstract Data Types serve as a specification and guide to formally verify working software. …

Disclaimer: I am not a financial advisor and I’m not telling you where to put your money. Either or both BTC and ETH values could drop to zero.

This is a bait and switch title, but only because a lot of people are asking a question that doesn’t make sense.

The question, “which will win, Bitcoin or Ethereum?” implies some misconceptions which do not reflect reality.

1. Misconception: Bitcoin and Ethereum are Currencies, and should be judged by how good they are at being money. Reality: Bitcoin and Ethereum are cryptonetworks, and should be judged by the value each network is capable of producing. …

Software development is an incredibly rewarding skill that can be extremely valuable. It’s remote-work friendly, and no matter where you live in the world, if you get good enough, you can qualify for great paying work ranging from $100k/year — $200k+/year (USD). Some of the highest-paid JavaScript developers make close to $500k/year. But to qualify for those great salaries, you have to get undeniably good at what you do.

Even if you’re already a professional software developer, you need to learn how to learn to code. Choosing a career in software development is choosing a path of lifelong learning.

In my role as a mentor I’ve had a peek into the learning process of hundreds of developers. What shocked me most is how much faster some learn than others. Some with little or no coding background learn new concepts more than 10 times faster than others who may have 10+ year’s experience in the craft. The secret is, you can, too. …

One gotcha that comes up frequently and has a serious impact on application performance is the tendency to accidentally fetch data in serial that could have been fetched in parallel. Don’t just drop an await in everywhere you use promises. Instead, think about the fetching dependencies. If you’re fetching more than one thing, make sure you fetch in parallel whenever you can. This will make a huge difference in your application’s performance.

Here’s some example code for you to play with.

Eric Elliott is a tech product and platform advisor, author of “Composing Software”, cofounder of EricElliottJS.com and DevAnywhere.io, and dev team mentor. He has contributed to software experiences for Adobe Systems, Zumba Fitness, The Wall Street Journal, ESPN, BBC, and top recording artists including Usher, Frank Ocean, Metallica, and many more. …