James Seymour-Lock

🇬🇧 British 👽 living in NYC 🇺🇸 🎨 Ex designer & FE dev 🌟 PM @RakutenUS & Partner @simpleasmilk

[Bennett @b_nnett]

Reverse-engineering the Whoop 5.0 to work without a subscription in 24 hours.

Starting now.

[Shopify Developers @ShopifyDevs]

Universal Commerce Protocol is now live for all merchants

Teach your agent to search billions of products with Shopify Catalog, build carts, and check out with the new UCP skill

[Tuomas Artman @artman]

Today is a hard day. I shared this note with the @linear team today: We’ve made the difficult decision to increase our workforce. This is not a cost-cutting exercise or a reflection of anyone’s performance. We’re simply reimagining every role for the agentic AI era. We’re hiring. We’re sorry about that.

[tobi lutke @tobi]

Now that the whole industry is united behind UCP, it’s worth re-reading how we built the protocol specifically to put merchants in charge of their checkout and commerce.

Building the Universal Commerce Protocol https://t.co/hqHCk7rGf5

[Shopify Engineering @ShopifyEng]

We reverse-engineered training data from thousands of merchant-created automations and fine-tuned Qwen3-32B into a tool-calling agent for Shopify Flow.

Results: 2.2x faster, 68% cheaper

The more interesting part: why we trained on Python instead of our own DSL, and what broke when benchmarks looked good but production didn't. ⬇️

[James Seymour-Lock @JamesSLock]

@philkyprianou Been doing the same this weekend. Power combo.

[Garry Tan @garrytan]

New item in my SOUL md tonight

[James Seymour-Lock @JamesSLock]

When returning a coupon on success, it is not automatically applied to the cart, and copying the coupon manually onClick provides no feedback that it was copied.

Both fixable by injecting JS into the template but would be great to support this out of the box.

[James Seymour-Lock @JamesSLock]

@ShopifyEng Small but useful fix: Forms App email input uses “text” not “email” so keyboards don’t switch to @ layout (and loose default browser field validation)

[tobi lutke @tobi]

New version of Universal Commerce Protocol (UCP 2026-04-08) just got finalized.

Carts (!), Catalog discovery features, Order status,, Signals support, ...

Big step step function upgrade for agentic commerce.

https://t.co/Q9hGXUUmLr

Coming soon to every Shopify storefront.

[Adi Polak @AdiPolak]

60–80% of Anthropic projects start without a PRD. Just Slack, context, fast pushback. No heavy docs. Makes me wonder if “good process” is just slow feedback in disguise.

[Indragie Karunaratne @indragie]

We partnered with @AnthropicAI to make it one click to go from Sentry’s root cause analysis to a code change generated by Claude!

[nick @n___vc]

more people should use spinners like this, those are sick

[Prince Canuma @Prince_Canuma]

mlx-vlm v0.4.3 is here 🚀

Day-0 support:
🔥 Gemma 4 (vision, audio, MoE) by @GoogleDeepMind
🦅 Falcon-OCR + Falcon Perception by @TIIuae
🪨 Granite Vision 4.0 by @IBMResearch

New models:
🎯 SAM 3.1 with Object Multiplex by @facebook
🔍 RF-DETR detection & segmentation by @roboflow

Infra:
⚡ TurboQuant (KV cache compression)
🖥️ CUDA support for vision models (Sam and RF-DETR)

Get started today:

> uv pip install -U mlx-vlm

Leave us a star ⭐️
https://t.co/7BvnEuzKvj

[tobi lutke @tobi]

The most AI proof job in the world is entrepreneurship

Use it to make products and services. Build more companies. On Shopify or otherwise.

[Rivet @rivet_dev]

Say hello to agentOS (beta)

A portable open-source OS built just for agents. Powered by WASM & V8 isolates.

🔗 Embedded in your backend
⚡ ~6ms coldstarts, 32x cheaper than sbxs
📁 Mount anything as a file system (S3, SQLite, …)
🥧 Use Pi, Claude Code/Codex/Amp/OpenCode soon

[Marc Hemeon @hemeon]

Middle management existed to pass information up and down the org chain.

AI removes this middle management layer and flattens orgs.

Great article suggests we only need 3 roles in an org:
ICs (builders), DRIs (owners), and player-coaches (builders who lead).

[Shopify @Shopify]

this is not a test
but your theme changes are

Rollouts is now live for all merchants
https://t.co/8p7VHPJXgS

[Romain Huet @romainhuet]

We’ve seen Claude Code users bring in Codex for code review and use GPT-5.4 for more complex tasks, so we thought: why not make that easier?

Today we’re open sourcing a plugin for it! You can call Codex from Claude Code with your ChatGPT subscription.

We love an open ecosystem!

[Cheng Lou @_chenglou]

My dear front-end developers (and anyone who’s interested in the future of interfaces):

I have crawled through depths of hell to bring you, for the foreseeable years, one of the more important foundational pieces of UI engineering (if not in implementation then certainly at least in concept):
Fast, accurate and comprehensive userland text measurement algorithm in pure TypeScript, usable for laying out entire web pages without CSS, bypassing DOM measurements and reflow