vasanthk

System Design Cheatsheet

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

Basic Steps

1. 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?

blasten

// Construct a table with table[i] as the length of the longest prefix of the substring 0..i
function longestPrefix(str) {
  
  // create a table of size equal to the length of `str`
  // table[i] will store the prefix of the longest prefix of the substring str[0..i]
  var table = new Array(str.length);
  var maxPrefix = 0;
  // the longest prefix of the substring str[0] has length
  table[0] = 0;

JoshCheek

class Symbol
  def enter(rider)
    (!self).call rider
  end
  
  def !@
    -> subject do
      method = subject.method(self)
      return method.call if method.arity.zero?
      method.to_proc.curry

jimweirich

Refactoring Kata

Here's an interesting refactoring challenge.

Refactor the tangle.c program described at http://axiom-developer.org/axiom-website/litprog.html with the goal of making it more readable and maintainable.

Some suggested guidelines and constraints. Of course, you can do

justinwiley

@test_deploy @javascript                                  # @test_deploy tag setup in cucumber.yml profile, @javascript runs in capybara-webkit
Feature: Smoke Test
  In order to test that the application is deployed
  As a caring developer
  I want to check a few features of the site
  
  Background:
    Given we are in the deploy environment
    
  Scenario: Logging in and checking basic navigation

ericallam

Open the postgresql.conf config file:

$> mate /usr/local/var/postgres/postgresql.conf

Uncomment the line with 'log_destination' and set it to 'syslog'

log_destination = 'syslog'

Open the syslog config:

balepc

# Redis configuration file example

# By default Redis does not run as a daemon. Use 'yes' if you need it.
# Note that Redis will write a pid file in /var/run/redis.pid when daemonized.
daemonize yes

# When run as a daemon, Redis write a pid file in /var/run/redis.pid by default.
# You can specify a custom pid file location here.
pidfile /var/run/redis.pid

balepc

#! /bin/sh
### BEGIN INIT INFO
# Provides:		redis-server
# Required-Start:	$syslog
# Required-Stop:	$syslog
# Should-Start:		$local_fs
# Should-Stop:		$local_fs
# Default-Start:	2 3 4 5
# Default-Stop:		0 1 6
# Short-Description:	redis-server - Persistent key-value db