Simon Hearne

Web Performance Architect

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About Simon


Hi! I’m a Web Performance Architect based in Surrey, UK. I have about a decade of experience in web performance, from selling and integrating performance monitoring tools to delivering multi-year consultancy projects. I am passionate about web performance, accessibility and user experience; I’m especially interested in the intersection of the three topics!

You can find me on Twitter, LinkedIn and GitHub.

Web performance architect?

Web performance architect is a broad term - I like it as it encompasses the work that I do. I’m not a software engineer or a pure consultant. The activities I conduct are varied:

  • tooling - determination, implementation & configuration
  • reporting - configuring automatic reports & delivering custom reports
  • goal-setting - how fast your user experiences should be for maximum engagement & business success
  • benchmarking - how fast your user experiences are compared to your competitors and universal benchmarks (like Core Web Vitals)
  • audits - finding and prioritising opportunities for improvement
  • evangelism - sharing performance knowledge and insight with engineering teams to build enthusiasm
  • education - training engineering teams on how to implement features to improve user experience

Note that I do not write code for my clients! There are software engineers who are much better than me at developing code, but I can offer a unique depth of understanding in my specialist fields.


I enjoy sharing ideas and experience by speaking at events. The web performance community is relatively small, but it is a community of passionate and inquisitive people. I’ve spoken at large industry conferences and small local meetups, I hope to help developers and website owners to deliver the best possible user experience.

See some of my talks over on the talks page, and get in touch if you think I might be a good fit for your event.

My Bio

I am a highly regarded web performance architect based in Surrey, UK. I am passionate about great user experience and have spent the past ten years helping some of the world’s biggest websites to deliver fast and inclusive user experiences.

I have a background in artificial intelligence, web engineering and technical consultancy.

Simon’s Bio

Simon is a highly regarded web performance architect based in Surrey, UK. Simon is passionate about great user experience and has spent the past ten years helping some of the world’s biggest websites to deliver fast and inclusive user experiences.

Simon has a background in artificial intelligence, web engineering and technical consultancy.

Bio Photo

Any of these photos may be used as my image.


I am not currently open for consultancy or freelance opportunities. I can personally recommend some great folks instead:

  • Andy Davies - Andy has tons of experience in performance tooling and optimisation. Get in touch for help with building a performance culture and implementing mature performance tooling.
  • Harry Roberts - Harry has a deep knowledge of browser fundamentals as well as the ability to help build enthusiasm within engineering teams. Get in touch for help with tactical and long-term performance projects.
  • Ivan Akulov - Ivan specialises in React and Webpack. Get in touch if you need general performance consultancy or specific performance support for a modern SPA architecture.

About Web Performance

Web performance is the art of creating seamless online user experiences.

Consumers expect websites and apps to respond instantly; delays of only 100ms can cause increases in frustration and reduce the likelihood of positive business outcomes. With a market shift towards smartphone browsing performance is more important than ever. However, in such a competitive world feature velocity is critical. Balancing the management of performance with feature velocity is critical to maximise the potential of your online presence.

Focus on Quality User Experience

You can have the best user experience, clearest calls to action and the best products at great prices, but if your web experiences take more than three seconds you are losing visitors’ attention and losing potential customers. Delivering fast experiences allows the rest of your hard work to deliver real business value. A slow user experience conveys a message of “clunky”, “old-fashioned” and “hard-to-use” (reference).

Get the back-end in order

Browsers can’t do anything until they receive critical content like HTML documents or API responses. Ensuring that your back-end is delivering content as efficiently and quickly as possible has numerous benefits. Shaving 100ms off an HTML document response will gain 100ms of user experience time for all pageviews, and delivering content more quickly means your back-end will scale to higher volumes of traffic without further investment!

Browsers are not created equally

Performance is in the eye of the beholder, and a user on a budget-friendly Android device has the same expectations as one on the latest flagship. Even a $1,000 phone does not protect you from overcrowded 4G cells or intermittent connectivity on the train. Analysing performance with an eye on the worst case scenario can reap huge speed benefits, as well as creating a more consistent experience for all users.

See beyond page load

Delivering a lightning-fast page load is important, but laggy interactions, slow executing JavaScript and janky scrolling can all send visitors away. Profiling and remediating expensive tasks which impact the user experience is key to increasing stickiness and improving business objectives.

Measure what matters

There are tens of timers available to measure performance, but which actually correlate with user experience and business success? What can be done to track, improve and alert on these timers? Knowing what to track and what the timers mean can be the critical factor in the success when creating a performance culture.