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Shipping products solo: the craft, the stack, the decisions.

A card quoting Greg Isenberg: $10 million businesses, $100 million businesses. Beside it, his own guest saying to use it for routing only. The expensive queue the episode claims to unlock costs $1.29 a month on the old model for a thousand enquiries, so nothing was rationed. A narrow tool with four clear uses.
Essay

Jev is a narrow tool with four clear uses. Greg Isenberg's $10m framing is not one of them.

24 September 2026
10 min read

Greg Isenberg's episode on Jev promised $10m businesses. His own guest says use it for routing and keep it away from your money. Here is each claim against the data, and the four conditions under which the tool earns its place.

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A results card reading: I said Jev beat GPT-5.4, five reruns can't tell them apart. Jev's lead over GPT-5.4 on the hard claims was 11.1 points in one run and 3.3 points averaged over five runs, which is 0.6 of one claim and not significant.
Build Log

I said Jev beat GPT-5.4. Five reruns can't tell them apart, at a fiftieth of the cost.

23 September 2026
13 min read

I published that Jev, TypeSafe's new model, beat GPT-5.4 by 11.1 points on hard fact-checks. Rerun five times, the two can't be told apart, Jev costs a fiftieth as much, and it lets more wrong claims through. Plus the five-run check.

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A results card reading: paying your AI to think longer didn't fix its mistakes. Up to 4.2x extra cost per answer for GPT-5.4, Sonnet 5 and Gemini 3.1 Pro, and no net gain on the hard claims for any of the three, one run per model.
Build Log

Paying your AI to think longer didn't fix its mistakes. It cost up to 4.2x more.

23 September 2026
14 min read

I gave three AI models room to think before answering, the fix everyone assumes will work. None got more reliable. It cost 2.4 to 4.2 times more per answer to find that out, and Jev, the cheap specialist model, still caught more of the mistakes.

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A card reading: what TypeSafe's own 0.8 auto-accept threshold buys you, and that a model's confidence threshold has to be tested at its own numbers, not a grid chosen in advance
Build Log

GPT-5.4 beats Jev on a confidence threshold, once tested at its own values.

21 September 2026
26 min read

I published a wrong finding last week: that GPT-5.4's confidence score has no usable threshold. It does, and swept over its own values it beats Jev at every…

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A results table comparing Jev with GPT-5.4, Claude Sonnet 5 and Gemini 3.1 Pro across 42 citation checks, split into an easy set and a hard set
Build Log

Jev is not an LLM. On the hard half it beat GPT-5.4, Gemini 3.1 Pro and Sonnet 5, at a fiftieth of the cost.

20 September 2026
18 min read

Jev does not generate text. You give it a question with defined answers and it hands back one of them plus a probability. On 42 citation checks it tied the…

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Social card reading: Your agent wrote a file. Your agent now reads that file as instruction. Nothing in between checked it.
Essay

The file your AI agent wrote for itself is making it worse. Ten minutes fixes it.

19 September 2026
7 min read

Somewhere in your project is a file your agent wrote, that your agent now reads as fact. Nothing in between checks it, so the good and the bad accumulate…

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Social card reading: Seven papers on AI that improves itself. Two ways it goes wrong, and both are the same part. The thing doing the scoring breaks, or nothing is scoring what you just added. The one technique that works freezes its evaluator outside the loop.
Essay

AI self-improvement fails at the scorer, in every case I could check

18 September 2026
21 min read

Google shipped a working self-improvement technique four days ago. One sentence in the paper explains why it works: the evaluator is frozen and sits outside the loop. Then look at the failures. Pseudo-labels that decay, a reward that gets gamed, a detector that gets bypassed, skills nobody scored. Different systems, same broken part. And if you run AI agents, you are already running the ungoverned version of this.

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Social card reading: seven hold no write path, two hold a shell under a read-only label, and all eleven can hand the write to an agent that has one. The door I left open is the file I write my own lessons into.
Build Log

AI agent security: find the file your agents can write and every agent reads

15 September 2026
16 min read

In one research harness, a payload sitting in the file that loads into the next agent's system prompt infected that agent 55% of the time. The same payload in…

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Dashboard card on deep navy. Kicker: TRADER-7 · SIGNAL MODEL AUDIT · 26 AUGUST 2026. Label RULE COMPLIANCE above a large gold figure: 37%. Below: a reward-to-risk floor stated four separate times in the prompt, met on 37 of every 100 proposals; 17 came back at exactly one to one. A row of proposal ticks, most slate and hollow, a minority green. Title: LLM ignoring its prompt? The prompt fix bought 10 points, the model swap bought the rest.
Essay

LLM ignoring its prompt? The prompt fix bought 10 points, the model swap bought the rest

28 August 2026
7 min read

Eight of 23 trade signals had the stop and the target at identical distance. The rule said 2:1 minimum. It was in the prompt four separate times.

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Dashboard card on deep navy. Kicker: TRADER-7 · RISK CONTROL AUDIT · 13 AUGUST 2026. Large gold figure: 7 of 26. Below: risk controls wired, believed working, and structurally incapable of ever firing, including the 15 percent emergency stop; found by exercising them, not by reading them. A row of status dots, most green, seven slate and hollow. Title: I audited 26 risk controls in my trading bot, 7 could never fire.
Essay

I audited 26 risk controls in my trading bot: 7 could never fire

14 August 2026
8 min read

The 15% drawdown halt was wired into two live code paths and could never fire. So I checked all 26 risk controls. Seven were dead. A control you cannot…

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Where I wanted three sentences, I got Proust. Below: a crash stops you and costs minutes, plausible wrong output stops nothing and costs the afternoon, and only one of them is being counted.
Essay

Opus 5 verbosity: where I wanted three sentences, I got Proust

5 August 2026
8 min read

I judge AI models by how often they make me swear. Opus 5 turned swearing into punctuation, and the reason is more interesting than I first thought.

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My auth check said healthy for three weeks on a dead credential. Below: the check ran and passed every time, the oracle was answering the wrong question, and the pattern costs more than the bug did.
Build Log

Why AI checks fail silently: 1,278 restarts behind a healthy status

3 August 2026
8 min read

My auth check said healthy for three weeks on a dead credential. The pattern behind it costs more than the bug did.

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Anthropic cut 80% of the prompt and I cut my instructions by 90%. Below: one stale copy telling twenty repos they were a different project, two files no session has ever read, and 453 lines loaded twice.
Build Log

Anthropic cut 80% of Claude Code's prompt. I cut my CLAUDE.md by 90% the same day.

3 August 2026
6 min read

An audit of 116 instruction files found one stale copy telling twenty repos they were a different project, two files no session has ever read, and 453 lines loaded twice. Here is what to delete from your own CLAUDE.md, and the method that beats judgement.

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Three status labels feeding a parser: two written as Done and Closed bounce off; one written as Resolved with a date passes through into a report.
Essay

My AI Agents Kept Losing My Work. The Fix Is Older Than Computers.

25 July 2026
6 min read

Seventeen finished pieces of work were invisible to my own tracking system, and the cause wasn't effort or memory. A Berkeley talk gave me the name for what fixed it: an ontology. Here's the version that fits a one-person company.

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Conference-thumbnail style graphic: a bordered jamiewatters.work badge, an orange markdown-logo square with the word Markdown, and giant white text reading Go find the customers
Essay

Garry Tan Just Described My Setup. Then I Noticed What He Left Out.

21 July 2026
7 min read

The YC president gave a talk describing, almost item for item, the AI system I already run. The validation lasted about ten minutes. Then I noticed the word neither of us was saying.

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I got phished from my own verified domain. Below: the key leaked by me in public, the domain verified and now the weapon, and it happened faster than any review cycle.
Essay

I Leaked an API Key and It Turned My Own Domain Into a Phishing Weapon

20 July 2026
6 min read

I got phished from my own verified domain, using an API key I'd leaked myself: what actually leaked, how fast it happened, and what I changed.

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Six AIs handed me the same lie, in unison. Below: unanimous reads as corroboration, but it was one claim repeated, so I check the source before I publish.
Build Log

I Almost Told You a Lie. Six AIs Handed It to Me, in Unison.

17 June 2026
7 min read

A field note from researching Graphify: the real privacy model, the honest token numbers, and why I check the source before I publish.

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Three-period performance comparison: Pre-Sprint 120 at 41.2% win rate +$964, Sprint 120-136 at 24.4% win rate -$217, Post-Sprint 136 at 47.6% win rate +$321.
Build Log

Same system, three different traders

26 May 2026
4 min read

Same code, same market, three time periods. One made $964, one lost $217, one's up $321. The difference wasn't the algorithm.

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An XML file full of PLACEHOLDER_X tags, fanned with eleven ghost copies. Caption: × 12 files. None ever filled in.
Build Log

BOS-AI had twelve XML files holding nothing

10 May 2026
4 min read

I checked the XML files BOS-AI used to store 'institutional memory' for thirty agents. Every tag was PLACEHOLDER_X. So I deleted all twelve.

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Three of fifteen Coinbase perpetuals. BTC and ETH traded, SOL excluded, XRP candidate, eleven skipped.
Build Log

I trade three coins, not fifteen

10 May 2026
4 min read

Coinbase lists 15 perp markets. Most alts are leveraged BTC with noise. The case for staying with three, and the one coin I'd seriously paper-test.

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