They're coool, eager to learn new things and they will never give up.

-Design before coding -Endless reading about new stuff -Always write tests

• Anything is legal (a.k.a. No Rules) No coding style, no style guidelines, no best practices. If it doesn't work it doesn't matter how pretty it is, and if it works nobody

• 1KB of code is tons of space if you have truly thought about the problem

• Through work we discover boundaries, through play we learn to work around them if you want to get past barriers or roadblocks you have to get creative and have fun with it.

1. They teach others.
2. They document things well.
3. They like to learn new things.

Great question! 👏 It takes many traits to reach the "extraordinary" level, as a developer, and the answers before me have done a great job at listing a few of them. Adding to them, or rather extending from them, here's a list that stood out for me, from my experience so far.

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They are great mentors, and aha moment maximisers.

I had to jump on the JavaScript bandwagon towards the end of 2015, when I quit my stint in Computational Biology (which involved a lot of Python, and a bit of C), and joined a web shop whose arsenal primarily included NodeJS.

Prior to my joining, they migrated their front-end setup from BackboneJS to ReactJS. At that point in time I didn't even have the faintest idea as to what React was, and what it entailed. Sanjay, the former CTO, (now pursuing research at MIT Media Lab) had this assignment for me.

Build a VanillaJS implementation of a Todo App, whose data layer is completely decoupled from the UI, and any change in the UI should update the data. A UI render should only happen, and only depend (both during initialisation, and while handling changes) on the data layer. Basically, the UI should be a pure function of the data.

I thought, that was a pretty rad design pattern ... and I came up with an implementation, soon after that. It was only after a bit later — when I was introduced to React, and the core principles behind it — when I realised the whole gist of React:

var UI = function(data)

Sanjay started the process of teaching React without actually teaching React, and when I realised it, it ended up being one of my best aha moments.

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Their code is an accumulation of beautiful, and modular black boxes.

In science, computing, and engineering, a black box is a device, system or object which can be viewed in terms of its inputs and outputs (or transfer characteristics), without any knowledge of its internal workings. Its implementation is "opaque" (black). Almost anything might be referred to as a black box: a transistor, an algorithm, or the human brain.

Extending on what @spsiddarthan said in his third point, the solutions cooked up by these bunch of "extraordinary" developers; gracefully handle all of the corner cases. They go up a notch, by taking it upon them to design code in a beautifully modularised way; which makes the process of "plug and play", with the "whole" parts of their code incredibly easy.

Not only that, they strive to help you write code in the same way.

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They always have an elegant, and a latest abstract view of the projects they're involved in.

If writing great code is on one hand; to have an innate knowledge of the entire system, and how additional "moving" parts, so to speak, would be, and should be introduced (read: modular black boxes), and how they would work with other parts of the system is a total different ball game; and they excel at it.

• Motivation: "It's easy dude!" - solves lots of problems first hand.
• Design: Think, Rethink, Re-engineer. It's like running the complete design virtually in our brain and thinking which piece of code goes where.
• Instant solution: Running to any problem? He/she tells you what is wrong before you even explain him the complete issue.

• They always designed first before they got to writing code. I am talking three weeks of design and not a single line of code. In fact, the coding just takes two or three days for any feature for them. The amount of emphasis they gave to design taught me how important design is.

• They made extremely good code review comments (which actually made the entire engineering team better) and always had the time for it. I haven't seen anybody take such good care of their code.

• The third one is more of a non-technical thing. Something that they taught me, whenever you come up with a solution, think of ways to break it, for the first solution you come up with is more often than not the worst solution you could come up with.

1. Friendly - He was always approachable inspite being under lot of pressure, he always greeted people with a smile. Thus I was not hesitant to ask silly questions to him and he answered them all gladly.

2. Helpful - Whenever I wanted help he always was ready to hear my problems. He never said I am busy, ask someone else.

3. Calm and collected - Always being calm is not that simple but I have never seen him angry.