Justin Smestad

Senior Staff Engineer @ Shopify

[Justin Smestad @jsmestad]

@josevalim @hugobarauna 🙌

[Dave Lucia @davydog187]

Announcing https://t.co/dIPm7iCS7I 🎉

The new home for Lua, the pure-Elixir Lua 5.3 VM for @elixirlang.

Scriptable, sandboxed, stupid easy.

Embed untrusted code (AI agent tools, user formulas, plugins) all on the BEAM, zero NIFs.

Plus a live playground 👇

[Justin Smestad @jsmestad]

Love the forward thinking mindset 👏

[José Valim @josevalim]

Woot! https://t.co/3q87OK38TD will now serve llms.txt for Elixir/Erlang packages if the accept header is text/markdown. If you have a package and you use ExDoc, update to the latest version (which generates .md files by default) and republish your docs.

[José Valim @josevalim]

Introducing vision mode: now your coding agent can take screenshots and record videos of your web app!

In the demo below, we asked Tidewave to implement a feature, record videos of the feature working on both desktop and mobile resolutions, and deliver them to Slack.

[Justin Smestad @jsmestad]

OpenAI killed Sora because they couldn't afford to run it. Then reallocated those servers to other products.

The token prices you see today are almost certainly subsidized. Your career has more runway than people think. https://t.co/3WrPYyQ885

[Adams @Adams_Tech_AI]

Tesla’s new range extender.

[Justin Smestad @jsmestad]

AI made "one more prompt" feel free. It's not. Every feature you add needs testing, docs, and maintenance nobody planned for.

Parkinson's Law, but for code.

https://t.co/011eS0SJyR

[Justin Smestad @jsmestad]

Agile assumes writing code is expensive. That's why we break work into the smallest possible slices.

AI just made starting over cheaper than refining. Engineers are generating entire features in one pass, then iterating on the whole thing.

https://t.co/3sSz7jhCm3

[Justin Smestad @jsmestad]

A kitchen full of talented cooks with no ticket system, and no one checking plates before they leave the window doesn't produce dinner. It produces chaos.

Engineering teams work the same way. AI just made the cooks faster. It didn't fix the kitchen.

https://t.co/vD1HgVfGme

[Mark Cuban @mcuban]

It's happening

https://t.co/UBie4ChQXH

[Adam Rackis @AdamRackis]

Finishing Alexandrescu’s Modern C++ Design and realizing you have to write React components at work tomorrow

[Branko @brankopetric00]

Kubernetes migration almost killed our startup.

Where we were:
- 8 EC2 instances
- Ansible for deploys
- Boring but working
- $1200/month AWS bill

Why we migrated:
- New investor wanted 'cloud-native'
- Engineers wanted K8s experience
- Competitors were using it
- Seemed like the future

6 months later:
- 3 engineers spending full-time on K8s
- AWS bill at $4500/month
- Deploys took longer than before
- More outages, not fewer
- Product development stalled

We rolled back:
- Moved to ECS Fargate
- 2 week migration
- Back to $1800/month
- Engineers back on features

K8s is amazing for scale. We weren't at scale. Technology should solve problems you actually have.

[Justin Smestad @jsmestad]

@alexlmiller Speechless

[Justin Smestad @jsmestad]

@stetsondoggett @MeVivekIndia But not the same antenna design

[MERICA MEMED @Mericamemed]

This song fits better😂

[Justin Smestad @jsmestad]

@robbyrussell Beautifully said Robby 👏

[Robby Russell @robbyrussell]

This isn't a Ruby vs. Go problem.

It's an "we hired 50 engineers so let's split everything apart" problem.

Here's what happens:

Company grows fast. Leadership comes from Big Tech. They bring their playbook.

Split the app into pieces. One piece per team. Everybody owns something.

It feels like progress.

Then the market shifts. Hiring stops. The VP leaves. The teams dissolve.

Five years later, you're maintaining a dozen systems with half the people.

The architecture assumed growth. Growth assumed the architecture.

Neither happened.

Those "handful of servers" everyone rolled their eyes at? They would've been fine.

They'd still be fine.

We architect for the future we want. Then we maintain it in the present we got.

The trap isn't microservices. The trap is designing for a team size that only exists on a hiring plan.

Build for the team you have. Not the team the VP from BigTechCo says you'll have.

Because when that VP leaves, the architecture stays.

[litquidity @litcapital]

Matt Levine’s summary of the AMD / OpenAI deal is hilarious

[Justin Smestad @jsmestad]

@jnunemaker …and man is it good duct tape! 🙌

[Justin Smestad @jsmestad]

🙌 Great work

[Zach Daniel @ZachSDaniel1]

Expert LS is out yall. #ElixirLang https://t.co/hwolBlAezf