Building AI products in public — code, metrics, and the failures too. First project ships this month.
India
Joined June 2026
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Jack — building in public retweeted
if it can't be verified, it doesn't get signed.
that's the rule under intent-layer, on testnet. it signs the intent it can verify and refuses the one it can't — "sell if tesla drops 20%" never signs, because it can't price tesla. no override.
keys never leave the device.
Jack — building in public retweeted
a finance guy joined a video call with his cfo and coworkers and wired out $25m. every face was fake. his was the only real one. we hardened the keys and left the person in the grass — and ai just aimed a factory at the person.
Jack — building in public retweeted
everyone's fixated on the $8.5m term labs lost. the number i can't shake is 0.5 — half an ETH of voting power. no bug, no phished key. the contracts obeyed the vote. "the DAO voted" needs to stop being a get-out-of-jail card.
Jack — building in public retweeted
safepal's breach cracked zero wallets. it leaked 39,798 buyers' names and home addresses off a checkout plugin instead. the safe held. somebody just mailed the map. wrote about the merch table nobody in this space guards.
Jack — building in public retweeted
and right on cue, while i was writing this: ruflo, 67k stars, shipped an mcp bridge that exposed 233 agent tools over http with no auth. one POST, full RCE, every key. the loaded gun wasn't even in a drawer. CVE-2026-59726.
Jack — building in public retweeted
Grok is very good at agentic tasks!
Agentic work is where @grok 4.6 lands hardest, taking the top spot on the Artificial Analysis Agentic Index at 59, tied with Claude Opus 5 Max.
The index measures tool use, planning, autonomy and complex problem solving rather than single answers
Grok 4.6 completes tasks in ~53 turns and ~0.5bn input tokens on average, against ~103 turns and ~2.0bn for Claude Opus 5 Max
Cost of $0.84 per task, putting it on the intelligence versus cost per task Pareto frontier
Enterprises buying agents pay per completed task, not per benchmark point. Turn efficiency is what determines whether a long-running workflow is affordable at volume.
Two labs now sit at the top of this index with very different cost structures. Buyers get real choice on price for the first time in agentic deployment.
Jack — building in public retweeted
defenders can see the future, and have a narrow window to uplevel their cybersecurity practices now.
key is to uplevel fundamentals and apply the best AI tools.
what we’re doing at OpenAI, and where other organizations can start: blog.gregbrockman.com/the-de…
Jack — building in public retweeted
last tuesday i gave an agent a key that could read every repo we own.
not because it needed them. because scoping one is annoying and i was in a hurry.
i noticed an hour later. had the revoke page open before i'd finished the thought.
Jack — building in public retweeted
Rain is hiring a Product Marketing Manager, Cards.
Remote · lead level
Rain builds stablecoin card infrastructure — card transactions, cross-border payments, B2B, remittances over Visa and Mastercard rails (backed by Sapphire, Galaxy, Khosla). This seat owns go-to-market for card product launches: positioning, revenue enablement, competitor tracking across the stablecoin-card space, and BD/platform training on card-issuing fundamentals.
Reports to the founding PMM. Product-marketing, not eng — but it's the story layer for real stablecoin payments.
Apply below.
Jack — building in public retweeted
last Tuesday i handed an agent a key that could read every repo we own. not because it needed them, because scoping one is annoying and i was in a hurry. that's the real story here, not the scary-AGI headlines. go scope your keys.
Jack — building in public retweeted
The correct answer is Tesla.
Every Tesla sold in the United States is assembled in the United States.
Jack — building in public retweeted
Rain is hiring a Product Marketing Manager, Cards.
Remote · lead level
Rain builds stablecoin card infrastructure — card transactions, cross-border payments, B2B, remittances over Visa and Mastercard rails (backed by Sapphire, Galaxy, Khosla). This seat owns go-to-market for card product launches: positioning, revenue enablement, competitor tracking across the stablecoin-card space, and BD/platform training on card-issuing fundamentals.
Reports to the founding PMM. Product-marketing, not eng — but it's the story layer for real stablecoin payments.
Apply below.
Jack — building in public retweeted
"Steve Jobs walked by and said the font city names weren't bad, but 'at least call them world-class cities.'
That's how Paoli and Wynwood became New York and Geneva."
Before joining Apple as the Macintosh artist, @SusanKare was an art history PhD who barely knew anything about computers.
She went on to design many of the icons, typefaces, and symbols that helped make the original Mac feel understandable and human, defining a visual language for personal computing that still influences software today.
At Startup School 2026, Susan shares the stories behind the Happy Mac, Command key, Chicago font, and more, along with the design lessons she learned from Steve Jobs, Paul Rand, and the original Mac team: make things meaningful and memorable, embrace constraints, iterate constantly, and use just enough detail to make an idea instantly clear.
00:00 — Making Things Meaningful and Memorable
01:51 — How Susan Joined Apple
05:01 — Designing the Original Macintosh
06:35 — A Computer Anyone Could Use
08:26 — Creating Chicago and the Mac Typefaces
11:47 — MacPaint and the First Icons
14:45 — The Story Behind the Happy Mac
17:08 — Why Simple Icons Work Better
18:25 — The Icons That Didn’t Work
21:23 — Designing Symbols That Last
22:44 — How the Command Key Got Its Symbol
25:20 — What Ancient Symbols Can Teach Designers
30:18 — Designing After Apple
36:32 — Lessons From Steve Jobs, Paul Rand, and More
Jack — building in public retweeted
your contract passed its audit. the money left anyway. in H1 2026 ~76% of stolen funds came from operational compromise — keys, signers, frontends — not smart-contract bugs (TRM Labs). 'audited' and 'safe' are different sentences.
Jack — building in public retweeted
openai shipped a reduced-safeguard cyber tier. the real question isn't whether they should have — it's what holds once the attacker has the same model. capability went symmetric, secrecy shrank. the moat is verification and the boundary.
Jack — building in public retweeted
It is an honor to have such a great team join @SpaceX
Jack — building in public retweeted
Grok 4.6 reaches #1 on @databricks
We worked with @spacexai to evaluate Grok 4.6 on the latest OfficeQA Pro V2 from @DbrxMosaicAI. It achieves the SOTA performance with @databricks's Genie harness!
The model is strongest on our document understanding and data reasoning tasks, and it is a very efficient driver!
