Sentinel: Your Web-Performance Watchman

Downloads and Resources

Periodically, I’ll make resources and assets available for download. These are usually extensive workshop slide-decks that can be viewed out of context.

N.B. If you download any of the below and then go on to hire me, be sure to mention your license key and I will deduct the cost of your download(s) from your final invoice.

What Is Site-Speed and Why Should I Care?

This free ebook talks you through the basics of site-speed and the vital role it plays in your business, whatever your industry.

Read the FREE ebook

Questions for Consultants: Useful Questions to Ask Your Clients

My first ebook comes in at just over 35,000 words. It’s a consultants guide to asking the very best questions to help your clients be more successful. I think you’ll like it.

Trade Secrets: Secret Performance Tools (and How to Use ’Em)

A half-day workshop all about secret and well-hidden performance tools.

Front-End Performance: Building Faster Websites

A mega-deck that goes with my full-day front-end performance workshop.

Hi there, I’m Harry Roberts. I am an award-winning Consultant Web Performance Engineer, designer, developer, writer, and speaker from the UK. I write, Tweet, speak, and share code about measuring and improving site-speed. You should hire me.

You can now find me on Mastodon.

Suffering? Fix It Fast!


  • inuitcss
  • ITCSS – coming soon…
  • CSS Guidelines

Next Appearance

  • Talk & Workshop

    WebExpo: Prague (Czech Republic), May 2024


I am available for hire to consult, advise, and develop with passionate product teams across the globe.

I specialise in large, product-based projects where performance, scalability, and maintainability are paramount.