Sam Lightfoot

Software in London. Trying to make things go faster.

[Sam Lightfoot @samlighty]

New post: I added Direct I/O support to Cassandra for compaction reads, cutting p99 read latency by 5x (and p50 a little).

Walks through the page cache mechanics, benchmarking, and when to enable it. Some funky charts along the way.

https://t.co/wvsVSGJVj7

[Sam Lightfoot @samlighty]

@samlambert @glcst did the same. Still hurts.

[Tobias Ziegler @Tobias__Ziegler]

If you're interested in SSD internals and how to use them efficiently, our paper, “How to Write to SSDs,” has been accepted to VLDB and is currently on the Hacker News front page. https://t.co/bwYAtPFTBg

[Sam Lightfoot @samlighty]

@eastdakota @threepointone Damn. I bet you can't afford it anymore.

[Sam Lightfoot @samlighty]

@eastdakota @threepointone I am very curious on its old pricing. How much was a main dish?

[Sam Lightfoot @samlighty]

@glcst @appfactory 6.2 kids!

[Sam Lightfoot @samlighty]

@_PSDev @xwanyex I think this is a very fair comment

[Sam Lightfoot @samlighty]

An excellent take

[Richard Bishop @bitsandhops]

During my time at @awscloud I tried to be an astute observer of how the Senior Principal and Distinguished Engineers carried themselves in new projects/teams and design reviews. This has made a lasting impact on how I operate as well as evaluate others.

All of these "Very Senior" engineers are smart but the absolute best ones were humble, secure, incredibly curious, and appreciated the history and path of a system. They can jump into whole new domains and immediately win over the people under them that ultimately do the work.

The worst Very Senior engineers show up and inflict their insecurity by asking divisive and superficial questions like "why didn't you use {{language foo}} or {{database bar}} or {{platform qux}}?" These very questions reveal their inner fear: they don't have the depth and breadth their position requires.

[Sam Lightfoot @samlighty]

@penberg @jorandirkgreef @samuellhuber +1 would love to see

[Sam Lightfoot @samlighty]

@dreamli60679407 Amazing - a great blogging opportunity 🙏

[Dave Kline @dklineii]

As a manager, it took me far too long to learn that meetings aren't actual work. I thought meetings drove output. Turns out, most meetings are about control, not collaboration. About signaling ambition versus pursuing it. If you can't pass these three tests, cancel the meeting:

[Sam Lightfoot @samlighty]

@penberg @rasbt @penberg overall thoughts on the book for LLM understanding? It's on its way to me now.

[Aman @Amank1412]

Someone really built this.

A VS Code extension that turns your AI agents into pixel art characters working inside a virtual office.

[Sam Lightfoot @samlighty]

@forked_franz @debasishg @claudeai Awesome - I will keep a close eye.

[Sam Lightfoot @samlighty]

@forked_franz @debasishg @claudeai Yup - I’m thinking from a Cassandra perspective

[Anthropic @AnthropicAI]

New Engineering blog: We tasked Opus 4.6 using agent teams to build a C compiler. Then we (mostly) walked away. Two weeks later, it worked on the Linux kernel.

Here's what it taught us about the future of autonomous software development.

Read more: https://t.co/htX0wl4wIf

[Sam Lightfoot @samlighty]

@Madisonkanna Glad it’s not just me. I also can’t find the flow state when using AI tooling, which is painful.

[Sam Lightfoot @samlighty]

Linus vibing. Things I did not expect.

[Guillermo Rauch @rauchg]

10 days into 2026:
- Terence Tao announces GPT & Aristotle solve Erdős problem autonomously
- Linus Torvalds concedes vibe coding is better than hand-coding for his non-kernel project
- DHH walks back “AI can’t code” from Lex podcast 6 months later

An acceleration is coming the likes of which humanity has never experienced before

[Sam Lightfoot @samlighty]

@BenjDicken I’ve never played this, but AoM was a killer