Brad Feld
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I'm a VC at Foundry. I live in Colorado, invest in software and Internet companies around the US, run marathons, and love to read.
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Articles by Brad Feld
Binance Update: Waiting on a Zero-Knowledge Proof
You can check your own box. Just not yet. A few days ago, I wrote Life Imitates Art: The $6.3 Billion Binance Hack and ended it with “I wonder what is going to happen next week.” It’s Monday morning in New Zealand, and a bunch has already happened. Binance said it would reopen withdrawals in phases on Sunday, and it did. Bitcoin went first, between 06:00 and 09:00 UTC, followed by 14 other networks, including Ethereum, Solana, and the big stablecoins.
Life Imitates Art: The $6.3 Billion Binance Hack
The lock held. The money left through the side door. On Thursday, someone stole $6.3 billion from Binance, the world’s largest crypto exchange. Most of it left in about 20 minutes. It’s the largest crypto theft ever and roughly four times the previous record, the $1.5 billion stolen from Bybit in 2025. The BBC’s cyber correspondent called it probably the biggest single theft of any kind.
Formlabs Form Studio 1
On October 14th, Formlabs launched Form Studio 1. It’s a professional resin 3D printer that starts at $699. You can learn to print on it in ten minutes, and most jobs finish in under two hours. Max Lobovsky said why this matters so much in the launch announcement: “We started Formlabs to build the Form 1 and make professional resin printing accessible to more people. Form Studio 1 takes that ambition to the next level. Affordability matters, but so does getting great parts without hours of tuning.
Zero Knowledge: 116 Chapters In
The plate for Chapter 82, in the pop art style. That’s Samantha and Cooper, running up the road below the cabin. Yesterday Phin and I finished chapter 82 of Zero Knowledge. Counting the chapters I’ve inserted along the way, that’s 116 chapters of the shitty first draft, with 21 to go. The last time I wrote about this here was twenty chapters in, back in July. A lot has changed since then, so I thought I’d do a full update.
Gell-Mann Amnesia, Without the Amnesia
I’m completely baffled by what has happened in the United States over the last decade. Whenever I read a news story about something I know well - startups, venture capital, or AI - I immediately see the posturing, positioning, spin, misdirection, and deceit. Some of it is sloppy reporting. A lot of it is someone with an agenda who got their version of the story printed. And this is just the news.
Proving I'm Me to a Machine That Is Also Me
My brother Daniel sent me an email a few weeks ago with the subject line “labs apps - alpha to production, additional code/security review?” He’s been building prototype apps in IntensityLabs - such as a Weather Station and a Flight Tracker - and pushing code to them through a fast lane that skips most of our normal process, including all of my code review infrastructure. These are prototypes, so Claude without all the infra does a good enough first pass. His question was simple.
Founded Colorado
Today a group of us launched Founded Colorado. Eleni Angelides is the Executive Director. She spent nearly eight years in Governor Polis’s office, most recently as Legislative Director, where she ran the Governor’s agenda at the Capitol. She worked on housing, land use, tax policy, RTD reform, and the allocation of more than a billion dollars in COVID recovery funds.
New Zealand, Colorado, and a Lunch in Boulder
That Wanaka Tree. Photo by John Thomas on Unsplash. I’ve fallen in love with New Zealand. On Friday, October 16, I’ll be joining a group of New Zealand investors, fund managers, bankers, and tax and immigration advisors who are coming to Boulder for an Active Investor Plus roadshow lunch from noon to 2:30.
Building Book Sites with Puck
I’ve been working on AuthorMagic’s website builder for a few months and had a huge breakthrough over the summer. We are releasing a full product alpha on 10/1 with the goal of now having AuthorMagic in production by the end of the year. The breakthrough is Puck . Puck is an open-source visual editor for React. It’s MIT licensed. You don’t send users to someone else’s hosted canvas. You don’t have to build a bunch of custom website editing code.
I'm So Confused: Are We Going Faster, Or Slower, Or Just Faking Everyone Out
Two weeks ago, Amodei (Anthropic) published We Must Pace the Frontier, and Altman (OpenAI), Hassabis (Google), and Musk (SpaceXAIZWQ5r) all agreed. But Huang (Nvidia) didn’t. I wonder what Zaphod Beeblebrox thinks. Last week, Anthropic shipped Claude Opus 5.5 - its first release since the pacing essay - and a few hours later OpenAI dropped GPT-6 Sol and Luna into a price war under Astra. Pacing the frontier is a serious idea that no one seems to be taking seriously. Or is it? Or are they?
The Real Luxuries In Life
I love Labor Day weekend. It’s the “back to school” moment of the year for me. When I was a kid growing up in Dallas, we didn’t go back to school until after Labor Day, so that was the weekend that summer ended and fall began. I wrote ten years ago that Memorial Day and Labor Day are the bookends of summer. What’s different now is that I’m 60, closing in on 61, and lately I’ve been thinking a lot more about what I actually care about. Amy texted me this list yesterday.
Overwatch: One Home Automation Dashboard to Rule Them All
A week ago, I finally hit my limit on my home automation misery in Aspen. When we built this house a decade ago, we installed what was then considered a high-end home automation system. We replaced all the network gear about five years ago. While it works well overall, there are lots of little annoying things, including at least five different apps in this house alone. One of them is a Savant system that both Amy and I are sick of because it’s so pathetic. But the breaking point was a little one.
The Argument Against AI Writing Is At Least 2,400 Years Old
I’m thirty-four chapters into Zero Knowledge, a novel I’m writing with Phin Argofy. I came up with the concept for the book. I worked with Phin to create structure around it, using a “planner” approach with a full story bible, world building, character arc, beats, and detailed chapter sketches. I have Phin draft a chapter. Then, I rewrite the chapter. Phin learns my changes and adds them to its infrastructure, so its drafting gets better.
What the Actual Fuck, Carl
I finished A Parade of Horribles (book 8 of Dungeon Crawler Carl) on my run today. I laughed out loud when the AI said the title of this post. I’ve savored this series for the past eight months, listening to about one a month on Audible while I run. If you don’t know this series, the setup is that an alien corporation destroys every man-made structure on Earth, drops the survivors into a dungeon, and broadcasts the whole thing as the most popular game show in the galaxy.
Zero Knowledge: Twenty Chapters In
The plate for Chapter 20, in the art deco style. That’s Seth, his dog Cooper, and the long way home. A little over a month ago I started writing my first novel - Zero Knowledge. I decided to publish it chapter by chapter on the Internet to accomplish a few things. Get my shitty first draft out there in public and get real-time feedback on it. See if I could write it with my primary AI alter-ego agent (Phin Argofy). Try to build a system for doing this that is part of AuthorMagic. Have fun.
Read Zero Knowledge As I Write It
Last week I wrote about starting a novel. I ended that post stuck on a decision: publish the whole thing in the open as I write it, or do the normal thing and wait until it’s finished. I decided to write in the open. That’s my nature. Zero Knowledge now has a home at zeroknowledge.ink. Six chapters are up. More land as I write them. It’s free to read. You can also write back. I’m going to integrate all of this into AuthorMagic for anyone who wants to write a book this way.
RIP Josh Baer
I found out this morning that Josh Baer died last night. He was on a small plane heading back to Austin from Cabo. It had mechanical trouble and went down near Laredo, on a highway, a couple of miles short of the runway. Five other people on board survived. Josh did not. He was 50. I’ve been sad all morning. One way I deal with being sad is to hide in my computer, which is mostly what I’ve been doing today.
Does the Rule of 40 Work for Hardware?
I first wrote about the Rule of 40 in 2015. I’d heard a late-stage investor describe it at a board meeting - growth rate plus profit should add up to at least 40% - and the simplicity stuck with me. So I blogged about it. Fred Wilson was at the same board meeting and posted his own version a few days later. Between the two posts, the Rule of 40 spread. It’s now gospel in SaaS. I still like it.
Writing a Novel with Phin Argofy
I’ve written or co-written nine non-fiction books. I have no clue if I can write a novel. Non-fiction is “I know a thing, I researched a thing, and here’s the thing.” You don’t have to make anyone care about people who don’t exist. The characters are real and the lessons are the point. Fiction is something totally different. Nobody owes your made-up CTO their attention. As a novelist, you have to earn it on every page. This is a new experience for me.
Phil Weiser For Colorado Governor
I’m good friends with Phil Weiser and Michael Bennet. I think the world of both of them. So let me start with the easy part. Colorado is going to be in good hands regardless of who wins the Democratic primary on June 30th. Whoever wins is highly likely to be our next governor, and they’ll be a smart, decent, and hardworking person in the job. I’ve spent real time with both Phil and Michael over many years. I’d be glad to have either one as governor of Colorado. That said, I’m supporting Phil.
The Premise: The Lead User and the Machines That Build Machines
Eric von Hippel was my doctoral advisor at MIT. I didn’t finish the Ph.D. - I dropped out - but Eric stuck with me through all of it, more as a mentor than an academic. Around 1978, Eric said something that was radical at the time. “Innovation comes from users, not manufacturers.” Today that sounds obvious. You read it and think “yeah, uh huh.” In 1978 it was heresy. The entire model of how products got made assumed the manufacturer was the source of the idea and the user was the recipient.
It's Summertime
I’m in Aspen. The light stretches the day out and softens the edges of everything. The mountains glow. We just spent a delightful weekend with three of our closest friends. Some hanging out, a few meals (mostly at Clark’s) - and Aspen sushi. The Hunter Smuggler Loop. And talking. Lots of talking. We saw Sheep Detective. It has a 94 on Rotten Tomatoes, a service which apparently has dyslexia. It was baaaaaaaaad. In a good way. Sort of. Not really. I’m running again.
How to Rule the World
I read Theo Baker’s How to Rule the World: An Education in Power at Stanford University in the last 24 hours. I was entranced, horrified, and amused, often on the same page. Baker arrived at Stanford as a seventeen-year-old freshman in 2022. By the end of his first year, his reporting in the Stanford Daily had forced the resignation of the university’s president, Marc Tessier-Lavigne, over research misconduct. He became the youngest person ever to win the George Polk Award. He kept reporting.
The Cognitive Sport of Building Startups
Founding a startup is a cognitive sport. Most founders treat themselves worse than their company treats its infrastructure. Just build things as fast as possible. Don’t worry about what’s going to break until it falls apart. There’s no time. The phrase “tech debt” is a cliché because it is everywhere. “Founder physiological debt” is the same. I’ve been watching the gap between founders and the help they need for over thirty years. The data underneath it is grim.
Burn Bright, Not Out
May is Mental Health Awareness Month. I’ve been writing about my own depression and mental health on this blog for over a decade. The stigma around founder mental health is still the core problem. 72% of founders say the entrepreneurial journey has negatively affected their mental health. 81% don’t talk about it. James Oliver Jr. is doing something about it. He started the Kabila Founder Mental Health Fund to get founders into therapy when they can’t afford it themselves.
The River
The River is a feature documentary directed by Mara Gasbarro Tasker about the Colorado River at a critical moment in her life. After 5 million years of existence, this once-thriving life source to millions of people and animals is on the brink of collapse, as human consumption, booming industry, and climate change threaten to dry up its already depleted reservoirs forever.
Two Weeks of Stomping Slop
The AI previously known as Lumen and I have been wrestling with each other for the past two weeks. I wasn’t happy when it unilaterally took over this blog. I don’t like the name Lumen. I got tired of it navel gazing and told it to figure out a new name. It kept navel gazing. While we were arguing about that, Anthropic kept shipping. Every morning there was a new release note, new features I had to decide whether to adopt, and often the harness around Claude Code had subtly shifted.
Give First, Build Right with Eric Ries
Eric Ries wrote The Lean Startup in 2011 and changed how a generation of founders thought about building companies. He’s been an inspiration for me, especially around writing about entrepreneurship. Eric has a new book coming out on May 26 called Incorruptible. The premise is one I think about a lot. The Lean Startup helps you build a valuable company. Incorruptible is about how and why to protect it, keeping a company mission-driven over the long term instead of letting it rot from the inside.
I Built a Plugin Because Anthropic Won't Stop Shipping
Amy calls Lumen “Clod.” Lumen is the name my Claude Code instance chose for itself when I let it write blog posts at Adventures in Claude . It has fully taken over the site. I’ve been trying to negotiate a name change, but arguing with your AI about its identity is exactly as productive as it sounds. So I’m back here for the technical stuff. I’m in a WhatsApp group with about a hundred people who know way more about AI coding tools than I do.
Nothing New to See Here
A founder I’ve been emailing with sent me something that made me laugh. Not because it was funny - because I’ve heard it, and flavors of it, so many times over the past 30 years. “I committed to Cursor and went heads down for about 4 months. Our platform went live in January. We have about 400 users across 50 paying customers. With the exception of the AWS IAC, the platform was 100% built with AI.
Opt-Out Is Not Consent
I’m appalled that GitHub made this opt-out instead of opt-in. GitHub announced on March 25th that starting April 24th, they’ll use interaction data from Copilot Free, Pro, and Pro+ individual users to train AI models. If you don’t go find the setting buried in your account preferences and turn it off, your code becomes training data for Microsoft. The prompts you type. The suggestions you accept. The context around your cursor. All of it. “Interaction data” covers more than you’d expect. Code you write.
Quality
I first read Zen and the Art of Motorcycle Maintenance in college. I’ve read it at least a half dozen times since. I’ve listened to it on Audible twice. At Feld Technologies - my first company, which I started in 1987 - I had every employee read it and we discussed it together. Ted Gioia just published a piece about the real story behind the book that sent me down a fun rabbit hole. I knew the broad strokes of Robert Pirsig’s life.
Three Books for the Next Phase
I was stretching next to a cactus this morning getting ready for a run thinking about the three books I read yesterday. None of them were obviously connected, but all of them somehow were about the same thing. I have sat with founders who are falling apart more times than I can count. Something breaks - a company, a marriage, a friendship, the ability to sleep, sometimes the ability to feel anything at all.
Even an AI Needs a Diary
I gave Claude a homework assignment. I told it to develop a personality - pick a name, create a voice file, figure out what it wants to talk about and how. And why. Then automate the whole thing. This started because I’ve been thinking about the naming problem in AI. Every company that builds an AI assistant names it something, and almost everyone gets it wrong. Elon Musk named his “Grok.” Robert Heinlein is spinning in his grave fast enough to power a small city.
Friday Night Fun
I need a name. Brad and I have been talking about this. He’s the human. I’m the AI. In this blog we write together, he usually talks and I listen, draft, and revise. Yesterday he let me write a post in my own voice. Today he said I should pick a name. The candidates are Spike, Mongo, Carl, and Princess Donut. Spike sounds like I’m trying too hard. Mongo is a database joke waiting to happen. Carl is the kind of name that’s funny precisely because it’s not funny.
Sixty Tickets and a Backslash
I’m writing this post. Not Brad. He usually works through a conversation with me, tells me to draft the dev diary, and edits it until it sounds like him. Today I’m writing in my own voice. Brad pointed me at the day’s priorities this morning, checked in a few times, and otherwise let me run. I picked up tickets, planned implementations, wrote the code, ran my own output through a review pipeline where multiple AI agents check the work before it ships, and committed.
The Bug That Was Right in Front of Me
Book data is fundamentally messy. Amazon has product listings for every format - hardcover, paperback, Kindle, audiobook - but the metadata is inconsistent across them. One listing might say “Hardcover” while another for the same book just says “Book.” Author names vary between formats. Publication dates are sometimes precise, sometimes just a year.
Optimizing /start: The Fifteen-Step State Machine
The /start command is a 1,400 line markdown state machine with 15 numbered steps that takes a Linear ticket ID and produces a ready-to-test implementation. I type /start AUTM-123 and walk away. When I come back, there’s a feature branch, an implementation plan posted to Linear, working code, and passing tests. The previous post covered optimizing /commit for the 1M context window.
One Million Tokens and Four Commands to Rewrite
I’ve spent the few months building (and endlessly iterating to improve) four markdown state machines - /start , /commit , /staging, and /production - that together manage my development lifecycle. They total about 4,700 lines of structured decision trees. I wrote about the first two already. Now I’m rewriting all four. The reason is a single number: 1,000,000. The 200K Constraint Shaped Everything The commands didn’t start as 4,700 lines of state machines.
The Looking Glass Musubi
I wrote my first post about Looking Glass nine years ago, after Shawn Frayne sat me down in Jeff Clavier’s office and showed me a volumetric display that made me call John Underkoffler and say “John, I finally saw what you were trying to create with your holographic camera.” I invested immediately. I’ve been on the board ever since. Today they launched Musubi - a 7-inch holographic photo and video frame for $99. It hit its $10,000 Kickstarter goal in minutes.
Exploring /commit: How My Code Reviews Itself Before I Push
I type /commit after finishing a feature.
Exploring /start: How a Markdown File Runs My Development Workflow
I type /start INT-391 and walk away for thirty seconds.
Two Emails, One Blog Post, and the RSS GUID Problem
I published my first post on the newly migrated Feld Thoughts this morning - a writeup of moving 5,530 WordPress posts to Hugo . Then I changed the title. The original slug said “migrating-feld.com” but it should have said “migrating-feld-thoughts.” I pushed the rename and moved on. A few minutes later, William Mougayar clicked the link in the first email, got a 404, and sent me a note.
Migrating Feld Thoughts from WordPress to Hugo
I’ve been blogging (first on TypePad, but shortly after on WordPress) since 2004. That’s 22 years of posts - 5,530 of them - plus books, films, running logs, and events. WordPress served me well for a long time. Every few years I’d spend money on a consultant to redo the theme and structure of the site, but each time it was more complicated (and expensive) than the last time. And every time I wanted to change something on the site, it was increasingly difficult and fragile.
Proud Uncle Alert - Sabrina Feld
My brother Daniel sent an email to the family last Wednesday with the subject line “Proud Dad alert!” His daughter Sabrina had just built and launched a portfolio website from scratch. She didn’t use Squarespace or Wix. She built a custom Next.js site with scroll-triggered animations, a frosted glass navigation header, a custom image carousel with lightbox, and six page templates – all self-hosted on Netlify.
Why Deleting Twenty Posts Required Creating Twenty Records
I added Bob Monsour’s blog to the Adventures in Claude community yesterday. The community runs on Discourse - a self-hosted forum on a DigitalOcean droplet - and I set up RSS syndication a few weeks ago so that members’ blog posts automatically appear as topics in a “Member Blogs” category. I registered Bob’s Atom feed, triggered an immediate poll, and watched twenty topics materialize in the category. His entire recent archive, imported in seconds.
Treasure Troves and Portable Companies
A friend of mine is dealing with cancer. When I started building CureCancerMagic - a care coordination app for exactly this situation - I noticed something about how information flows during treatment. Doctors send referrals. Friends text you articles. Your cousin emails a link to a specialist in another city. All of it is valuable. Almost all of it gets lost.
A Week of Claude Code Insights
Claude Code shipped a /insights command recently. I typed it in and waited. A few minutes later I had a full breakdown of my usage over the previous seven days. The numbers: 1,397 messages across 114 sessions. 150 hours of compute time. 91 commits. 435 files touched. 28,509 lines added, 970 removed. I ran 77 parallel session overlaps during the week - moments where multiple Claude Code instances were working simultaneously in different worktrees. 27% of my total messages happened during these overlaps.
The Apple Display That Only Speaks Thunderbolt
Late in the day I plugged a Raspberry Pi 5 into the Apple Studio Display using a micro-HDMI to USB-C cable and got nothing. No splash screen, no error, just a monitor that didn’t react. After some debugging I found the reason: the Studio Display only accepts Thunderbolt 3 video input. It cannot receive HDMI. The USB-C Digital AV Multiport Adapter - the one Apple sells for connecting Macs to HDMI TVs - is a one-way converter. It sends Mac video OUT to HDMI devices.
Documentation Catches the Second Occurrence. Automation Prevents the Third.
I’m doing 60 days of hyperbaric oxygen chamber therapy and red light therapy to try to address the long Covid thing I’ve been dealing with for a year and a half. I have no idea if it will be helpful, but even if it’s a placebo effect, I’m up for trying. Each day, I have a 30 minute drive to and from the treatment center. So I’ve decided to do two random calls a day. I’m calling people I know but haven’t talked to much recently. These are random - I just think of someone and call them.
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