Hello! My name is Lydia Hallie, passionate about everything JavaScript, web performance, and creating in-depth technical content.

I enjoy researching and exploring the intricaties of technologies we use on a daily basis; from JavaScript engines to browser internals, web security ,networking, cloud infrastructure, bundlers , you name it.

Combining this with my software engineering background in JavaScript (Node.js, TypeScript) and React (Next.js, Expo) enables to me help teams identify and implement optimizations that greatly enhance speed, SEO, security, DX, and user experience.

Beyond coding, I love creating in-depth technical content with a focus on clear visualizations. It challenges me to truly comprehend the technology and go as low-level as possible while still making it enjoyable to watch/read. I believe that being able to explain complex concepts in a simple yet technically accurate way is a good test to see how well you truly understand the technology you're working with. This not only deepens my own understanding, I also hope it helps others understand certain topics better, inspire them to keep on learning, and get excited about today's tech!

I'd love to help you. Feel free send an email to me@lydiahallie.com or send a DM on Twitter (opens in a new tab)!


  • 🌷 I'm from Utrecht, the Netherlands
  • 🐣 Born in April 1998
  • 💻 Started my professional career in 2017, focus on JavaScript performance, React, TypeScript, and devops
  • 🎨 I make my visualizations in Apple Keynote!

Some random facts?

  • 🌍 I've traveled to 26 countries so far, lots of solo trips! Highly recommend
  • 🃏 I'm addicted to playing Solitaire, Sudoku and those annoying IQ puzzles (they don't help lol)
  • 👩‍✈️ I'm a pilot! Just small planes for now but definitely plan to fly bigger ones in the future
  • 🥑 My insta username might be @theavocoder but I don't like avocados at all haha, sorry