🇬🇧 British 👽 living in NYC 🇺🇸 🎨 Ex designer & FE dev 🌟 PM @RakutenUS & Partner @simpleasmilk
Joined November 2009
- Tweets 45,271
- Following 2,238
- Followers 7,672
- Likes 33,406
1,738 Photos and videos
James Seymour-Lock retweeted
Jun 9
One of my personal favorite features announced at WWDC will I suspect be a sleeper hit: container machines, allowing your Mac to run a lightweight, persistent Linux environment with your home directory and repos automatically mounted: github.com/apple/container/b…
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James Seymour-Lock retweeted
May 18
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
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James Seymour-Lock retweeted
May 8
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.
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James Seymour-Lock retweeted
May 3
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 shopify.engineering/ucp
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James Seymour-Lock retweeted
Apr 23
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. ⬇️
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Apr 11
@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)
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Apr 11
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.
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James Seymour-Lock retweeted
Apr 9
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.
ucp.dev/2026-04-08/specifica…
Coming soon to every Shopify storefront.
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James Seymour-Lock retweeted
We partnered with @AnthropicAI to make it one click to go from Sentry’s root cause analysis to a code change generated by Claude!
🗣️We just launched our Claude Agent integration
Now when Seer finds a bug, it can hand it off to Claude—with all the context Sentry has about the issue—to write the fix and create a PR for you.
Check out the docs for more: docs.sentry.io/organization/…
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James Seymour-Lock retweeted
Apr 2
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 ⭐️
github.com/Blaizzy/mlx-vlm
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James Seymour-Lock retweeted
Apr 1
The most AI proof job in the world is entrepreneurship
Use it to make products and services. Build more companies. On Shopify or otherwise.
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James Seymour-Lock retweeted
Mar 31
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
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James Seymour-Lock retweeted
Mar 31
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).
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this is not a test
but your theme changes are
Rollouts is now live for all merchants
x.com/Shopify/status/1998819…
stop rolling the dice on theme changes
schedule for more control
A/B test for more insights
Rollouts lets you do both right from the admin
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James Seymour-Lock retweeted
Mar 30
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!
Mar 30
I built a new plugin! You can now trigger Codex from Claude Code!
Use the Codex plugin for Claude Code to delegate tasks to Codex or have Codex review your changes using your ChatGPT subscription.
Start by installing the plugin:
github.com/openai/codex-plug…
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James Seymour-Lock retweeted
Mar 28
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
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James Seymour-Lock retweeted
Mar 25
a few weeks ago someone called work without AI “tradwork” and i can’t stop thinking about it
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