Rent Versus Buy
A subscription makes idle capacity feel like loss. API pricing makes every call feel like spend. Same tokens, opposite behavior.
jonathannen.com
Thoughts from Jon Williams. Say Hi at x.com/jonathannen
Latest posts
Twenty Twenty Sprints
How I structure my day in 2x20-minute sprints an hour -- a pomodoro shape that fell out of AI coding.
Anthropic's definition of safety is too narrow
Anthropic treats safety as a model behavior problem. Claude Code's recent month shows it's also reliability, pricing, and communication. They're where trust actually gets spent.
Vibe Designing
Claude Design isn't vibe-coding. It's vibe-designing. And treating it like a coding tool might be holding it wrong.
Straight to Claude
The moment a task or chore enters my head, it goes into Claude Code.
Context Windows for People
You can't A/B test a performance review. When the feedback loop is too slow to iterate, you have to start with the right inputs -- and then try to break them before reality does.
Let It Rate
With messy people data and long feedback loops, output schema isn't just an interface concern -- it's a useful steering mechanism.
Being A Better Manager in the AI Era
AI is collapsing the value of coordination. If that was your primary value as a manager, you have a problem.
People Systems Are the Next Codebase
An HR team vibe coded their own performance review tool. The interesting part isn't the tool -- it's what it means for how we treat people processes.
Resisting AI
The skeptics say AI is another Kubernetes — a misapplied tech hype cycle. I think it looks more like the Internet, and probably much more.
Make it impossible, or Make it safe
My dad's safety philosophy turns out to be a great framework for agentic coding: don't bubble-wrap the world, engineer one where you can take risks.
Vibe Coding Dev Tools
Invest in your AI dev tools, but vibe code them. They will be eventually be disposable.
Early observations from Interviews with Engineering Teams Adopting AI
The teams succeeding with AI aren't the ones with the best tooling. They're the ones that changed how they work.
The first PRs shipped by Customer Success.
Last week our customer success team shipped their first two pull requests. It changed how we ship and how we communicate.
Battleship Prompts
Same task, three different prompts. See which one gets closest. It's surprisingly effective and makes you a better prompter.
We're not vibe engineering
Vibe coding is the headline. Engineering a new SDLC is the actual work.
A Demographic Collapse of Developers
Junior developer hiring is stalling. Meanwhile, the senior pipeline doesn't refill itself.
The Claude Dichotomy
AI is creating a genuine dichotomy: teams drowning in AI-supercharged chaos, others are thriving. The difference is in the approach to transformation.
Clear Your AI Mind
Your context window is not a diary, don't forget to /clear.
Tool Augmented Prompting
Your linter, compiler, and test runner already talk to the AI. Make them say something useful.
Spin the Bottle Neck
The bottleneck in software has moved. Teams are still optimising for the old (wrong) one.
Still choose boring technology
Dan McKinley's classic advice on "choosing boring technology" is even more true in the AI era.
Do as I say not as I TODO
Your AI assistant holds a mirror up to your codebase. 5 ways to make sure it reflects the good parts.
AI Prompts are Wishes
AI prompts are wishes. The more powerful the wish, the bigger the potential for the curse.
Skills I'm ceding to AI
My shortlist of coding skills I'm genuinely comfortable handing to AI.
No agents, no plan, ship it
Why I prefer single-prompt one-shotting with AI coding tools over multi-step agents, swarms, and planning modes.
Don't Believe the Hype
AI vibe coding tools aren't truly there yet. But early adopters can see they will be. Those aren't the same thing.
Infinite Monkeys
AI coding tools need a high degree of parallelism to work. Without it, you're just watching a monkey type.
Know Your Models
Software engineers routinely juggle multiple AI models. Other disciplines will be encountering this soon.
On choosing optimism?
Optimism isn't the naive, easy position — it's the one that demands the most from you.
Faster horses and AI Productivity
Not all AI productivity gains are real. A framework for telling the faster horses from the genuine improvements.
Sharpening the Axe (Branch)
Using an Axe branch when iterating on your AI coding workflow.
A Daily AI Chat
I'm using a single long-running AI chat each day to prioritize in the morning and summarize at the end.
Adaptive, not Compliance
AI is brilliant at adaptive processes. It's a terrible fit for compliance ones.
Skilled Humans in the Loop
Human-in-the-loop only works if the human has (and retains) the skills to actually be in the loop.
My Current AI Coding Workflow
A snapshot of how I'm working with AI coding tools right now (Feb 2026).
Your Brain on GPS
What happens to our navigation skills when we rely on GPS? And what might happen to our coding skills with AI?
The Mythical Machine-Month
We're moving into an era where a team of 5 engineers can outperform a team of 50.
The 'Comment-Only' Prompt
A new prompt I've found useful: Don't make any changes, just put a comment where you intend to make changes.
What does it take to build towards 100 PRs/day per engineer?
My day, my tooling, and the system changes that make high-volume AI-assisted shipping possible.
Having a Senior Moment
2026: Wait, AI is a senior engineer now?
AI and abandonware
Can we have AI maintain abandoned npm packages?
The pace of AI tools
The rate that AI coding tools are adding workflow features is wild.
Return to Office (or) Agent
Is RTO throwing away organizational infrastructure that AI agents need?
What's the deal with Bitcoin Core and Bitcoin Cash?
Bitcoin forked in August 2017. What are the differences between Bitcoin core and Bitcoin cash?
Is a Bitcoin bubble hiding in the mining infrastructure?
In this series I look at some of the failure modes for Bitcoin. For this article, we look at mining infrastructure.
Could ICOs be a triumph of the commons?
The tragegy of the commons suggests self-interest spoils shared resources. Could blockchain ownership counter this?
Are ICOs a Ponzi Scheme in waiting?
Many ICO tokens are relatively low-volume. This opens up the prospect of price manipulation.
Building super-detailed personas?
Getting all your persona assumptions down is important. You need to be wrong as much as you're right.
What is the 'why now' of your startup?
What is the 'Why Now' of your startup?