nem035

Studying for a Tech Interview Sucks, so Here's a Cheat Sheet to Help

This list is meant to be a both a quick guide and reference for further research into these topics. It's basically a summary of that comp sci course you never took or forgot about, so there's no way it can cover everything in depth. It also will be available as a gist on Github for everyone to edit and add to.

Data Structure Basics

###Array ####Definition:

• Stores data elements based on an sequential, most commonly 0 based, index.
• Based on tuples from set theory.

nem035

Better local require() paths for Node.js

Problem

When the directory structure of your Node.js application (not library!) has some depth, you end up with a lot of annoying relative paths in your require calls like:

var Article = require('../../../models/article');

Those suck for maintenance and they're ugly.

Possible solutions

nem035

function * just (...values) {
  yield * values;
};

function first (iterable) {
  const iterator = iterable[Symbol.iterator]();

  const { done, value } = iterator.next();
  if (!done) return value;
};

nem035

What I Wish I'd Known About Equity Before Joining A Unicorn

Disclaimer: This piece is written anonymously. The names of a few particular companies are mentioned, but as common examples only.

This is a short write-up on things that I wish I'd known and considered before joining a private company (aka startup, aka unicorn in some cases). I'm not trying to make the case that you should never join a private company, but the power imbalance between founder and employee is extreme, and that potential candidates would

nem035

// ...
  var app = new EmberApp(defaults, {
    hinting: false,

    babel: {
      includePolyfill: true,
      optional: [
        "es7.decorators",
        "es7.classProperties",
        "es7.asyncFunctions"

nem035

DOM selectors

var elements = query`.${className}`;

Localization

var message = l10n`Hello ${name}; you are visitor number ${visitor}:n!

nem035

DOM selectors

var elements = query`.${className}`;

Localization

var message = l10n`Hello ${name}; you are visitor number ${visitor}:n!

nem035

Latency Comparison Numbers
--------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

nem035

• 🎨 when improving the format/structure of the code
• 🚀 when improving performance
• ✏️ when writing docs
• 💡 new idea
• 🚧 work in progress
• ➕ when adding feature
• ➖ when removing feature
• 🔈 when adding logging
• 🔇 when reducing logging
• 🐛 when fixing a bug

nem035

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});