I guess everyone who’s been in the programming world long enough has heard about this data structure at least once. Hash tables excel when you need rapid lookups, quick inserts, and fast deletions…

Learn how to evaluate runtime performance in Chrome DevTools.

If you have a good test suite, you may be able use pytest fixtures to identify memory and other resource leaks.

I am building 10MPage.com which captures the state of the internet in 2025. Every internet user is allowed to upload a small image of 64x64…

5 minutes to 11 seconds with Node.js is possible?

Because no one has time to wait for slow APIs in the age of instant gratification.

I was recently made maintainer of the json gem, and aside from fixing some old bugs, I focused quite a bit on its performance, so that it is now the fastest JSON parser and generator for Ruby on most benchmarks.

Performance chapter of the 2024 Web Almanac covering Core Web Vitals, with deep dives into the Largest Contentful Paint, Cumulative Layout Shift, and Interaction to Next Paint metrics and their diagnostics.

Learn how browser turn your code into functional website from high-level architecture to the specifics of the rendering pipeline.

Understanding server-side waterfalls with RSCs and client-side waterfalls we're familiar with and why server-side waterfalls are probably better.

Have you ever wondered how the biggest services in the world, like AWS and Netflix, achieve single-digit millisecond response times…

How we rolled out zstandard and other improvements across our gateway cluster to reduce the amount of bandwidth that’s used by our clients.

Track data flowing through Java programs.

We'll walk through key configurations like Tiered Cache, Cache Reserve, and crafting specific cache rules, highlighting how these optimizations benefit Pillser's users.

Page Speed Insights and Lighthouse can't evaluate performance across your entire stack of services and apps. You need something more powerful: tracing.

What's the Difference Between Throughput vs. Latency? How to Use Throughput vs. Latency with AWS.

Rate limiting is a technique to restrict the number of requests made to network resources at one time. Learn how it works.

Essay on the benefits of speedy software, and how it affects user perception of engineering quality and overall usability

Learn how we discovered what was slowing down large database queries, and what we did to make Postgres queries 1000x faster.

How web devs can tackle high latency networks and enhance UX and the role React Server Components plays in this.

'npm scripts' are executed by JavaScript developers and CI systems all around the world all the time. Despite their high usage they are not particularly well optimized and add about 400ms of overhead. In this article we were able to bring that down to ~22ms.

What data is put on the stack and what data is put on the heap?

romgrk's personal blog

A comprehensive guide about hotspots in your codebase, cognitive complexity and avoiding disasters by being proactive. An article inspired by the book "Your Code as a Crime Scene" by Adam Tornhill with practical examples.

TL;DR: If your font file is significantly larger than 20K you may ask yourself "How did I get here?".For images I think we (web developers) have a sense of how many bytes we can expect an image we see on a page to be. A JPEG photo? 100-ish K is ok for a decent quality. Less is nice. How about 200K?