Andrew Keats Steakeye

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

Clarify and agree on the scope of the system

User cases (description of sequences of events that, taken together, lead to a system doing something useful)
- Who is going to use it?
- How are they going to use it?

System design cheat sheet

It can be used for interviews or assessments.

1. Understand problem and scope:

Recognize stakeholders and prioritize them. Create RACI matrix
Understand business drivers of the project
Recognize end-users of the project and understand how they will use that system
Check functional requirements
Define external dependencies
Suggest additional features
Remove items that interviewer considers out of scope

1. Clone your fork:

git clone git@github.com:YOUR-USERNAME/YOUR-FORKED-REPO.git

2. Add remote from original repository in your forked repository:

cd into/cloned/fork-repo
git remote add upstream git://github.com/ORIGINAL-DEV-USERNAME/REPO-YOU-FORKED-FROM.git
git fetch upstream

The three design patterns (Adapter, Facade and Bridge) all produce the result of a clean public API. The difference between the patterns are usually due to a subtle context shift (and in some cases, a behavioural requirement).

Adapter

The primary function of an Adapter is to produce a unified interface for a number of underlying and unrelated objects.

You will notice this pattern being utilised in many applications. For example, ActiveRecord (the popular Ruby ORM; object-relational mapping) creates a unified interface as part of its API but the code underneath the interface is able to communicate with many different types of databases. Allowing the consumer of the API to not have to worry about specific database implementation details.

The principle structure of this pattern is:

Setting up p4merge as diff and merge tool on Windows. Tried for Git version 1.8.4.msysgit.0.

Two alternatives are explained: using the command line, and directly editing the config file.

Setting up from the command line

Being the installation path "C:Program Files\Perforce\p4merge.exe", just run:

$ git config --global diff.tool p4merge

##Sass Functions Cheat Sheet

RGB Functions
HSL Functions
Opacity Functions
Other Color Functions
List Functions
Map Functions
Selector Functions
String Functions

Using SCSS

Website: http://sass-lang.com/
Docs: http://sass-lang.com/guide
Tutorial: https://www.codecademy.com/learn/learn-sass

	// Puppeteer cheat sheet
	// gonna try and do for puppeteer what capybara got: https://gist.github.com/zhengjia/428105



	// to delete an input value
	function DeleteInput(page, inputSelector, word){
	// input must be focused
	page.type(inputSelector, '')
	for (let i = 0; i < word.length; ++i) {

	$Username = "su"
	$Password = "password"

	$group = "Administrators"

	$adsi = [ADSI]"WinNT://$env:COMPUTERNAME"
	$existing = $adsi.Children \| where {$_.SchemaClassName -eq 'user' -and $_.Name -eq $Username }

	if ($existing -eq $null) {

	// === Arrays

	var [a, b] = [1, 2];
	console.log(a, b);
	//=> 1 2


	// Use from functions, only select from pattern
	var foo = () => [1, 2, 3];