Hi! I'm Lydia Hallie
I'm a 25-year-old software engineer specializing in JavaScript (TypeScript), React (Next.js, Expo), and Web Performance.
2023
Blog Post
Why do reflows negatively affect performance?
January 2024 ∙ FrontendMasters
![Advanced JavaScript Quiz by Lydia Hallie](/_next/image?url=https%3A%2F%2Fstatic.frontendmasters.com%2Fresources%2F2023-12-05-javascript-quiz%2Fthumb.jpg&w=3840&q=75)
Course
Advanced JavaScript Quiz
December 2023 ∙ FrontendMasters
Blog Post
Comparing MySQL, PostgreSQL, and MongoDB
November 2023 ∙ Vercel
Blog Post
Enhancing Security for Redirects and Rewrites
October 2023 ∙ Vercel
Blog Post
SQL vs. NoSQL Databases
November 2023 ∙ Vercel
![Performance in React and Next.js by Lydia Hallie](/_next/image?url=%2Fimages%2Fwebp19.webp&w=3840&q=75)
Conference Talk
Performance in React and Next.js
October 2023 ∙ Vercel
![Images on the Web by Lydia Hallie](/_next/image?url=https%3A%2F%2Fvercel.com%2F_next%2Fimage%3Furl%3Dhttps%253A%252F%252Fimages.ctfassets.net%252Fe5382hct74si%252F3cto8kfPs3M7kzIlB7u7IC%252Fcee705be98c97543fbbc08f8606e9756%252Fimage_84.png%26w%3D3840%26q%3D75%26dpl%3Ddpl_7MNou8DBrrs287ysZgqKDnWoAToP&w=3840&q=75)
Blog Post
Images on the Web
October 2023 ∙ Vercel
![Understanding XSS Attacks by Lydia Hallie](/_next/image?url=https%3A%2F%2Fvercel.com%2F_next%2Fimage%3Furl%3Dhttps%253A%252F%252Fimages.ctfassets.net%252Fe5382hct74si%252F4BuOVI5ytH0DYwEYNpLfJY%252Fc16f75dd41923fef0720968cdbe771c4%252FGroup_513650__4_.png%26w%3D3840%26q%3D75%26dpl%3Ddpl_7MNou8DBrrs287ysZgqKDnWoAToP&w=3840&q=75)
Blog Post
Understanding XSS Attacks
October 2023 ∙ Vercel
![Content Security Policy by Lydia Hallie](/_next/image?url=%2Fimages%2Fblogposts%2Fcsp.png&w=3840&q=75)
Blog Post
Content Security Policy
October 2023 ∙ Vercel
![Understanding the SameSite attribute by Lydia Hallie](/_next/image?url=https%3A%2F%2Fvercel.com%2F_next%2Fimage%3Furl%3Dhttps%253A%252F%252Fimages.ctfassets.net%252Fe5382hct74si%252F22Up7AARd24QKi1jQPBlhX%252F0308a6dc8b930a8a0bdb8c587054375f%252Fimage_57.png%26w%3D3840%26q%3D75%26dpl%3Ddpl_7MNou8DBrrs287ysZgqKDnWoAToP&w=3840&q=75)
Blog Post
Understanding the SameSite attribute
October 2023 ∙ Vercel
![Understanding XSRF attacks by Lydia Hallie](/_next/image?url=https%3A%2F%2Fvercel.com%2F_next%2Fimage%3Furl%3Dhttps%253A%252F%252Fimages.ctfassets.net%252Fe5382hct74si%252F7ewWP9g93wVoNlbYh7YZ8V%252F9708670288d58532ea83915d98321bf4%252Fimage_43__1_.png%26w%3D3840%26q%3D75%26dpl%3Ddpl_7MNou8DBrrs287ysZgqKDnWoAToP&w=3840&q=75)
Blog Post
Understanding XSRF attacks
October 2023 ∙ Vercel
![Understanding Cookies by Lydia Hallie](/_next/image?url=https%3A%2F%2Fvercel.com%2F_next%2Fimage%3Furl%3Dhttps%253A%252F%252Fimages.ctfassets.net%252Fe5382hct74si%252F7dfRMDKhYaZBulOdFrCVVi%252F7e47d45bfda48654576734b94cc78f89%252Fimage_31.png%26w%3D3840%26q%3D75%26dpl%3Ddpl_7MNou8DBrrs287ysZgqKDnWoAToP&w=3840&q=75)
Blog Post
Understanding Cookies
October 2023 ∙ Vercel
![First Input Delay (FID) vs. Interaction to Next Paint (INP) by Lydia Hallie](/_next/image?url=https%3A%2F%2Fvercel.com%2F_next%2Fimage%3Furl%3Dhttps%253A%252F%252Fimages.ctfassets.net%252Fe5382hct74si%252F5pgZe3wP1JHIVLwuS60jt7%252F3a53b9094562818ea586f2e71eb796df%252FGroup_513805.png%26w%3D3840%26q%3D75%26dpl%3Ddpl_7MNou8DBrrs287ysZgqKDnWoAToP&w=3840&q=75)
Blog Post
First Input Delay (FID) vs. Interaction to Next Paint (INP)
September 2023 ∙ Vercel
![Optimizing Web Fonts by Lydia Hallie](/_next/image?url=https%3A%2F%2Fvercel.com%2F_next%2Fimage%3Furl%3Dhttps%253A%252F%252Fimages.ctfassets.net%252Fe5382hct74si%252F4lj3jWbLcNhSTBndUXNQ0V%252F32de746b3ae4ba1e350061a71cdf43bc%252Fimage_48.png%26w%3D3840%26q%3D75%26dpl%3Ddpl_7MNou8DBrrs287ysZgqKDnWoAToP&w=3840&q=75)
Blog Post
Optimizing Web Fonts
September 2023 ∙ Vercel
![How React 18 Improves Application Performance by Lydia Hallie](/_next/image?url=%2Fimages%2Fblogposts%2Freact-18-performance.png&w=3840&q=75)
Blog Post
How React 18 Improves Application Performance
Vercel | Jul 19, 2023
![An Introduction to Streaming on the Web by Lydia Hallie](/_next/image?url=%2Fimages%2Fblogposts%2Fstreaming-on-the-web.png&w=3840&q=75)
Blog Post
An Introduction to Streaming on the Web
Vercel | Jun 22, 2023
![Keynote Speaker by Lydia Hallie](/_next/image?url=%2Fwebp8.webp&w=3840&q=75)
Conference Talk
Keynote Speaker
Vercel Ship | May 1, 2023
![Advanced Web Development Quiz by Lydia Hallie](/_next/image?url=%2Fwebp9.webp&w=3840&q=75)
Course
Advanced Web Development Quiz
FrontendMasters | Apr 3, 2023
![Streaming for Serverless Node.js and Edge Runtimes with Vercel Functions by Lydia Hallie](/_next/image?url=%2Fimages%2Fblogposts%2FOG_Image__9_.png&w=3840&q=75)
Blog Post
Streaming for Serverless Node.js and Edge Runtimes with Vercel Functions
Vercel | Mar 28, 2023
![Behind the scenes of Vercel's infrastructure by Lydia Hallie](/_next/image?url=%2Fimages%2Fblogposts%2Fvercel1.png&w=3840&q=75)
Blog Post
Behind the scenes of Vercel's infrastructure
Vercel | Jan 27, 2023
2022
![Optimizing Web Fonts in Next.js 13 by Lydia Hallie](/_next/image?url=%2Fimages%2Ffontog.png&w=3840&q=75)
Blog Post
Optimizing Web Fonts in Next.js 13
7 Dec, 2022
![Keynote Speaker by Lydia Hallie](/_next/image?url=%2Fwebp18.webp&w=3840&q=75)
Conference Talk
Keynote Speaker
Next.js Conf | Oct 25, 2022
![Architecting a scalable infrastructure by Lydia Hallie](/_next/image?url=%2Fwebp17.webp&w=3840&q=75)
Conference Talk
Architecting a scalable infrastructure
React India | Sep 22, 2022
![Improve how you architect web apps by Lydia Hallie](/_next/image?url=%2Fimages%2Ftalks%2Flogrocket.jpg&w=3840&q=75)
Podcast
Improve how you architect web apps
LogRocket | Aug 3, 2022
![Build your own web framework by Lydia Hallie](/_next/image?url=%2Fwebp16.webp&w=3840&q=75)
Blog Post
Build your own web framework
Vercel | Jul 28, 2022
![Modern intro to app development with React and Expo by Lydia Hallie](/_next/image?url=%2Fimages%2Ftalks%2Fexpo.jpeg&w=3840&q=75)
Workshop
Modern intro to app development with React and Expo
App.js Conf | Jun 3, 2022
![A Tour of JavaScript & React Patterns by Lydia Hallie](/_next/image?url=%2Fwebp15.webp&w=3840&q=75)
Course
A Tour of JavaScript & React Patterns
FrontendMasters | Jun 1, 2022
![Implementation and use cases of modern rendering patterns by Lydia Hallie](/_next/image?url=%2Fimages%2Ftalks%2Fdevx.png&w=3840&q=75)
Conference Talk
Implementation and use cases of modern rendering patterns
DevX | May 5, 2022
![Modern Rendering Patterns by Lydia Hallie](/_next/image?url=%2Fimages%2Fblogposts%2Frendering-og.png&w=3840&q=75)
Blog Post
Modern Rendering Patterns
4 May, 2022
![Advanced Rendering Patterns by Lydia Hallie](/_next/image?url=%2Fwebp14.webp&w=3840&q=75)
Conference Talk
Advanced Rendering Patterns
Reactathon | May 3, 2022
![Patterns.dev with Lydia Hallie and Addy Osmani by Lydia Hallie](/_next/image?url=%2Fimages%2Ftalks%2Fhanselminutes.jpg&w=3840&q=75)
Podcast
Patterns.dev with Lydia Hallie and Addy Osmani
Hanselminutes | Apr 21, 2022
![Upgrading Next.js for instant performance improvements by Lydia Hallie](/_next/image?url=%2Fimages%2Fblogposts%2FOG_Image__1_%20(1).png&w=3840&q=75)
Blog Post
Upgrading Next.js for instant performance improvements
Vercel | Mar 17, 2022
2021
![Certified Associate in Python Programming: PCAP-31-03 by Lydia Hallie](/_next/image?url=%2Fwebp11.webp&w=3840&q=75)
Course
Certified Associate in Python Programming: PCAP-31-03
KodeKloud | Nov 12, 2021
![Patterns.dev by Lydia Hallie](/_next/image?url=%2Fimages%2Fpatterns.jpeg&w=3840&q=75)
Book
Patterns.dev
Sep 26, 2021
![Leveling Up Your JS by Lydia Hallie](/_next/image?url=%2Fimages%2Fkentpodcast.jpeg&w=3840&q=75)
Podcast
Leveling Up Your JS
Kent C. Dodds | Sep 4, 2021
![Asynchronous Iterators and Generators by Lydia Hallie](/_next/image?url=%2Fimages%2Ftalks%2Fiterators.png&w=3840&q=75)
Conference Talk
Asynchronous Iterators and Generators
Web Directions | Aug 6, 2021
![Lydia Hallie vertelt ons over React development by Lydia Hallie](/_next/image?url=%2Fimages%2Fcodeklets.png&w=3840&q=75)
Podcast
Lydia Hallie vertelt ons over React development
CodeKlets | Jun 29, 2021
![Keynote Speaker by Lydia Hallie](/_next/image?url=%2Fwebp13.webp&w=3840&q=75)
Conference Talk
Keynote Speaker
Next.js Special Event | Jun 15, 2021
![Native for React Developers by Lydia Hallie](/_next/image?url=%2Fwebp10.webp&w=3840&q=75)
Workshop
Native for React Developers
App.js Conf | May 11, 2021
![Certified Entry-Level in Python Programming: PCEP-30-02 by Lydia Hallie](/_next/image?url=%2Fwebp12.webp&w=3840&q=75)
Course
Certified Entry-Level in Python Programming: PCEP-30-02
KodeKloud | Mar 13, 2021
2020
![Explaining Code Through Analogies and Visualizations by Lydia Hallie](/_next/image?url=%2Fimages%2Ftalks%2Fdevdiscuss.png&w=3840&q=75)
Podcast
Explaining Code Through Analogies and Visualizations
DevDiscuss | Dec 1, 2020
![Understanding the V8 JavaScript Engine by Lydia Hallie](/_next/image?url=%2Fwebp1.webp&w=3840&q=75)
Conference Talk
Understanding the V8 JavaScript Engine
Reactathon | Dec 1, 2020
![Incrementally adopting Next.js by Lydia Hallie](/_next/image?url=%2Fwebp2.webp&w=3840&q=75)
Conference Talk
Incrementally adopting Next.js
Next.js Conf | Oct 25, 2020
![Understanding Git by Lydia Hallie](/_next/image?url=%2Fwebp3.webp&w=3840&q=75)
Course
Understanding Git
KodeKloud | Aug 18, 2020
![Modern JavaScript: ES6 and beyond! by Lydia Hallie](/_next/image?url=%2Fimages%2Fcourses%2Fmodern-javascript-es6-and-beyond.jpeg&w=3840&q=75)
Course
Modern JavaScript: ES6 and beyond!
VueSchool.io | Mar 30, 2020
![⭐️🎀 JavaScript Visualized: Promises & Async/Await by Lydia Hallie](/_next/image?url=%2Fimages%2Fblogposts%2Flbkswjafvaeynxnrjuoq.png&w=3840&q=75)
Blog Post
⭐️🎀 JavaScript Visualized: Promises & Async/Await
Dev.to | Apr 14, 2020
![Software Developers Journey Podcast by Lydia Hallie](/_next/image?url=%2Fimages%2Ftalks%2Fdevjourney.png&w=3840&q=75)
Podcast
Software Developers Journey Podcast
DevJourney | Feb 17, 2020
![💡🎁 JavaScript Visualized: Generators and Iterators by Lydia Hallie](/_next/image?url=%2Fimages%2Fblogposts%2F6pba7yczwddtemu0cla2.png&w=3840&q=75)
Blog Post
💡🎁 JavaScript Visualized: Generators and Iterators
Dev.to | Jan 16, 2020
![🎉👨👩👧👧 JavaScript Visualized: Prototypal Inheritance by Lydia Hallie](/_next/image?url=%2Fimages%2Fblogposts%2Fyjxz6x93jaxk4wgmpnw5.png&w=3840&q=75)
Blog Post
🎉👨👩👧👧 JavaScript Visualized: Prototypal Inheritance
Dev.to | Jan 3, 2020
2019
![🚀⚙️ JavaScript Visualized: the JavaScript Engine by Lydia Hallie](/_next/image?url=%2Fimages%2Fblogposts%2Fq0vxo5pcm6qjo14k0ami.png&w=3840&q=75)
Blog Post
🚀⚙️ JavaScript Visualized: the JavaScript Engine
Dev.to | Dec 13, 2019
![A Day with Remote Software Engineer Lydia Hallie by Lydia Hallie](/_next/image?url=%2Fwebp7.webp&w=3840&q=75)
Documentary
A Day with Remote Software Engineer Lydia Hallie
Honeypot | Nov 29, 2019
![⚡️⛓JavaScript Visualized: Scope (Chain) by Lydia Hallie](/_next/image?url=%2Fimages%2Fblogposts%2Fha.png&w=3840&q=75)
Blog Post
⚡️⛓JavaScript Visualized: Scope (Chain)
Dev.to | Nov 20, 2019
![🔥🕺🏼 JavaScript Visualized: Hoisting by Lydia Hallie](/_next/image?url=%2Fimages%2Fblogposts%2Fkaf11wh85tkhfv1338b4.webp&w=3840&q=75)
Blog Post
🔥🕺🏼 JavaScript Visualized: Hoisting
Dev.to | Nov 20, 2019
![✨♻️ JavaScript Visualized: Event Loop by Lydia Hallie](/_next/image?url=%2Fimages%2Fblogposts%2Fek7ji4zrimozpp2yzk0a.webp&w=3840&q=75)
Blog Post
✨♻️ JavaScript Visualized: Event Loop
Dev.to | Nov 20, 2019
![Modern Web Performance Trivia by Lydia Hallie](/_next/image?url=%2Fwebp6.webp&w=3840&q=75)
Conference Talk
Modern Web Performance Trivia
London Web Performance | Nov 13, 2019
![Advanced React by Lydia Hallie](/_next/image?url=%2Fimages%2Ftalks%2Freact.png&w=3840&q=75)
Conference Talk
Advanced React
React Live | Sep 27, 2019
![Advanced GraphQL by Lydia Hallie](/_next/image?url=%2Fimages%2Ftalks%2Fgraphql.png&w=3840&q=75)
Workshop
Advanced GraphQL
JavaScript workshops | Aug 8, 2019
![✋🏼🔥 CS Visualized: CORS by Lydia Hallie](/_next/image?url=%2Fimages%2Fblogposts%2Fpokn6wy4nwkx7s5bkd9w.png&w=3840&q=75)
Blog Post
✋🏼🔥 CS Visualized: CORS
Dev.to | Jul 27, 2020
![Database Integration Testing by Lydia Hallie](/_next/image?url=%2Fwebp5.webp&w=3840&q=75)
Conference Talk
Database Integration Testing
Prisma Day | Jun 19, 2019
![Hackathon at the European Central Bank by Lydia Hallie](/_next/image?url=%2Fecb.png&w=3840&q=75)
Documentary
Hackathon at the European Central Bank
European Central Bank | May 6, 2019
2018
![Mastering Data Structures and Algorithms in JavaScript by Lydia Hallie](/_next/image?url=%2Fimages%2Fcourses%2F5631962463076352.png&w=3840&q=75)
Course
Mastering Data Structures and Algorithms in JavaScript
Educative.io | Sep 6, 2018
![Data Structures and Algorithms by Lydia Hallie](/_next/image?url=%2Fimages%2Ftalks%2Ftree.png&w=3840&q=75)
Book
Data Structures and Algorithms
Jun 18, 2018
![React Redux Notes by Lydia Hallie](/_next/image?url=%2Fimages%2Ftalks%2Freactredux.png&w=3840&q=75)
Book
React Redux Notes
May 2, 2018
![JavaScript Notes by Lydia Hallie](/_next/image?url=%2Fimages%2Ftalks%2Fjs.png&w=3840&q=75)
Book
JavaScript Notes
Apr 2, 2018
![Understanding Git by Lydia Hallie](/_next/image?url=%2Fimages%2Fgit1.png&w=3840&q=75)
Book
Understanding Git
Jan 12, 2018