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?

paulirish

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

• elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

ndarville

Business Models

Advertising

Models	Examples
Display ads	Yahoo!
Search ads	Google

acdha

#!/bin/bash
#
# Report time to first byte for the provided URL using a cache buster to ensure
# that we're measuring full cold-cache performance

while (($#)); do
    echo $1
    curl -so /dev/null -H "Pragma: no-cache" -H "Cache-Control: no-cache" \
        -w "%{http_code}\tPre-Transfer: %{time_pretransfer}\tStart Transfer: %{time_starttransfer}\tTotal: %{time_total}\tSize: %{size_download}\n" \
        "$1?`date +%s`"