Matt Hobbs Nooshu

ChatGPT Resources

Context

ChatGPT appeared like an explosion on all my social media timelines in early December 2022. While I keep up with machine learning as an industry, I wasn't focused so much on this particular corner, and all the screenshots seemed like they came out of nowhere. What was this model? How did the chat prompting work? What was the context of OpenAI doing this work and collecting my prompts for training data?

I decided to do a quick investigation. Here's all the information I've found so far. I'm aggregating and synthesizing it as I go, so it's currently changing pretty frequently.

Model Architecture

Webfonts are huge and blocking

July 25th, 2016

Webfonts on GOV.UK block initial render and are surprisingly big at 200kb GZIPed

Measured impact

I have measured a 2g/3g connection with fonts blocked to see the difference it could make to lazy-load the font with the following results

Notes about tools for measuring and learning about performance.

Tools that can be used

Name + Link	Usecase
Google Pagespeed Insights (PSI)	Measuring load and render performance, highlighting basic responsive design issues
What does my site cost	Measuring how much the payload of a website costs in different countries
Webpagetest	Measuring load and render performance, with comprehensive video and waterfall charts, on a choice of devices and connection speeds
Google Lighthouse ("Audits" tab in Chrome Devtools)	Measuring load and render performance, and some basic best practice, PWA, and accessibility criteria

Web Performance

Requirements

You need to have the latest version of Node. Preferably, you're using 9.8.0, but the latest LTS should work as well.
You should have npx installed using npm install -g npx.
Install the React Developer Tools.

Repositories

Articles

NOTICE: I moved most of this content that I no longer maintain within this gist over to its own repo here https://github.com/radum/performance-testing-framework

Performance API

// https://github.com/WICG/paint-timing
performance.getEntries();

Stuff I wish I'd known sooner about service workers

I recently had several days of extremely frustrating experiences with service workers. Here are a few things I've since learned which would have made my life much easier but which isn't particularly obvious from most of the blog posts and videos I've seen.

I'll add to this list over time – suggested additions welcome in the comments or via twitter.com/rich_harris.

Use Canary for development instead of Chrome stable

~~Chrome 51 has some pretty wild behaviour related to console.log in service workers. Canary doesn't, and it has a load of really good service worker related stuff in devtools.~~

NOTE: This is no longer an experiment! You can use the accessibility inspector in Chrome Devtools now, including a fantastic color contrast inspection tool. Read more: https://developers.google.com/web/updates/2018/01/devtools#a11y

Just like any good element inspector helps you debug styles, accessibility inspection in the browser can help you debug HTML and ARIA exposed for assistive technologies such as screen readers. There's a similar tool in Safari (and reportedly one in Edge) but I like the Chrome one best.

As an internal Chrome experiment, this tool differs from the Accessibility Developer Tools extension in that it has privileged Accessibility API access and reports more information as a result. You can still use the audit feature in the Chrome Accessibility Developer Tools, or you could use the aXe Chrome extension. :)

To enable the accessibility inspector in Chrome stable:

The issue:

..mobile browsers will wait approximately 300ms from the time that you tap the button to fire the click event. The reason for this is that the browser is waiting to see if you are actually performing a double tap.

(from a new defunct https://developers.google.com/mobile/articles/fast_buttons article)

touch-action CSS property can be used to disable this behaviour.

touch-action: manipulation The user agent may consider touches that begin on the element only for the purposes of scrolling and continuous zooming. Any additional behaviors supported by auto are out of scope for this specification.

Charles Proxy Map Remote over HTTP or HTTPS

The Map Remote tool changes the request location, per the configured mappings, so that the response is transparently served from the new location as if that was the original request.

HTTP

Using this feature for http resources does't require anything else apart from just configuring your Map Remote entry.

Always make sure you are clearing your cache before you test. Even if Charles is configured properly you might not see the changes unless the browser gets the resource again from the server and not for its local cache.

	#!/bin/bash
	files=$(git diff --cached --name-only \| grep '\.jsx\?$')

	# Prevent ESLint help message if no files matched
	if [[ $files = "" ]] ; then
	exit 0
	fi

	failed=0
	for file in ${files}; do