Csaba Palfi csabapalfi

Csaba Palfi - Web perf like it's 2017

Everything is changing so fast: new devices, JS framework of the day, the expectations of our users. How do we respond?

What's the current state of the art in web performance? What's worth measuring and how? What are some common pain points?

Let's find out!

Csaba is a contract full-stack developer currently helping HomeAway.com in building their landing pages.

=importxml("http://maps.googleapis.com/maps/api/directions/xml?origin=" & A1 & "&destination=" & A2 & "&sensor=false&alternatives=false","//leg/distance/value")/1000

Caches all the way down

https://ldnwebperf.org/events/caches-all-the-way-down/

Layers of caching in the browser

(kind of Chromium specific here and there)

1. MemoryCache

rendering process specific, short-lived
strict matching, same resource type, etc, CSP
everything (even no-cache, except for no-store)

	sudo scutil --set ComputerName "$1" && \
	sudo scutil --set HostName "$1" && \
	sudo scutil --set LocalHostName "$1" && \
	sudo defaults write /Library/Preferences/SystemConfiguration/com.apple.smb.server NetBIOSName -string "$1"

	<?xml version="1.0" encoding="UTF-8"?>
	<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
	<plist version="1.0">
	<dict>
	<key>BackgroundColor</key>
	<data>
	YnBsaXN0MDDUAQIDBAUGFRZYJHZlcnNpb25YJG9iamVjdHNZJGFyY2hpdmVyVCR0b3AS
	AAGGoKMHCA9VJG51bGzTCQoLDA0OV05TV2hpdGVcTlNDb2xvclNwYWNlViRjbGFzc00w
	IDAuODk5OTk5OTgAEAOAAtIQERITWiRjbGFzc25hbWVYJGNsYXNzZXNXTlNDb2xvcqIS
	FFhOU09iamVjdF8QD05TS2V5ZWRBcmNoaXZlctEXGFRyb290gAEIERojLTI3O0FIUF1k

	#!/bin/bash

	# dependencies: curl, jq
	# usage ./psi.sh "https://www.google.com" 90 mobile

	BASEURL=https://www.googleapis.com/pagespeedonline/v4/runPagespeed

	url=$1
	threshold=$2
	strategy=${3:-desktop}

	# I used this to have a feel of which domains to prefetch DNS for on a quite heavy page

	# top 10 domains in order
	cat landingpage.har \| jq '.log.entries[].request.url' \| sed -e 's\|"https\?://\|\|' -e 's\|/.*\|\|' \| awk '!x[$0]++' \| head -10
	# top 10 domains by frequency
	cat landingpage.har \| jq '.log.entries[].request.url' \| sed -e 's\|"https\?://\|\|' -e 's\|/.*\|\|' \| sort \| uniq -c \| sort -rn \| head -10

	BACKGROUND="/Library/Desktop Pictures/Solid Colors/Solid Aqua Blue.png"
	sqlite3 ~/Library/Application\ Support/Dock/desktoppicture.db "update data set value = '$BACKGROUND'" && killall Dock