I re-read that book every 10 years and try to think carefully about whether what Brooks wrote still holds.
The last three times I read the book, everything held.
This time, I'm not so sure: AI does change things significantly. Perhaps not for all teams and not all scales of software, but in my case (solo developer, complex software system) I did measure a 12x productivity increase [1].
Also, some of the problems Brooks describes became much easier, if not borderline trivial with AI. For example, maintaining design documentation that stays consistent with the software being built. I do this and it is no longer a problem.
I still think most of what Brooks wrote is applicable today. I think the biggest difference is that AI enables smaller teams to work on larger systems, and the biggest benefit is for single-person teams (ahem) like me. I see it as another step that allows me to tackle larger systems: the previous one was Clojure which reduced incidental complexity so significantly that I was able to develop the system to the size it is today. AI is the next step: it allows me to build features that would have taken me years in a span of months. Not because of "vibe coding", but primarily because I can work on a set of design documents and turn my ideas into a coherent design.
[1] For the nitpickers: yes, measured, not guessed. Yes, the metric was reasonable. No, it wasn't "lines of code" or something equally silly, in fact one of my main goals is reducing code size as much as possible. Yes, I compared larger time periods: 2 months with AI to an average of 12 months of the previous year. No, the metric wasn't gamed: this is a solo business and I have no interest in gaming my own metrics. I earn a living from this work, so this is as objective as it gets.
Dario Amodei said in the most recent interview with Dwarkesh that Anthropic currently gets achieves an increase of around 20-30% coding productivity, which tracks with my experience. What do you do to reap orders of magnitude more?
Also, how much more money do you make? Or are you working less?
I can clearly see, and feel, Dario's associates' "increased productivity" in their Claude Code/Chat/Cowork desktop product...
So many updates, pretty much daily, so many tweaks to the interface. Sometimes the tweaks are a bit dumb, sometimes completely trivial, and other times they just undo what they did previously.
My favorite examples of their newfound velocity:
1. When there is a nice feature that was easily discovered, and then it was gone...
2. When the "customize" section moves around to random places in settings, or entirely out of it
Special mention to their scatterbrained keyboard shortcuts strategy
> What do you do to reap orders of magnitude more?
I don't know what Dario Amodei says, does, how Anthropic is run or structured, or what kind of people work there, so I can't comment on that.
I do know about myself, though. The increase is very real, measured by the number of (Linear) issues resolved. No, I haven't changed how I open or close those issues, I've been using the system for years. During the first three months of 2026 I went through 12x more issues per month than during past years.
But I guess I am not an "average programmer": 35 years of experience means I can work with AI as I would with a small (but very skilled) team. I can architect systems, notice unnecessary complexity, and intuitively choose solutions that are more maintainable. And I am a single-person company, with no managers to report to, KPIs to achieve, presentations to make, etc.
I do not make "more money". It's a mature SaaS. Changes in revenue are over the long term, on a scale of years more than months, and implementing features is no longer enough: marketing is needed for more growth.
But, to be honest, I am tired of defending myself this way. It's not the first time I post this metric, I thought people would find it an interesting data point. Instead, I get downvoted (see my comment above which currently sits at -1 in spite of being objective and factual), and then get plenty of responses asking me to defend my statements.
Come to think of it, I'd rather not convince people about AI increasing productivity so much. I'm not really sure why I bother to post here anymore. I'd rather have everyone (including my competition) believe whatever they want to believe and not use AI.
Sounds like a blog post on your experience would be very interesting.
Like a sibling comment - I'm also curious about what that 12x means for you and your business - same revenue at fewer hours? More revenue, fewer hours? Etc.
The last three times I read the book, everything held.
This time, I'm not so sure: AI does change things significantly. Perhaps not for all teams and not all scales of software, but in my case (solo developer, complex software system) I did measure a 12x productivity increase [1].
Also, some of the problems Brooks describes became much easier, if not borderline trivial with AI. For example, maintaining design documentation that stays consistent with the software being built. I do this and it is no longer a problem.
I still think most of what Brooks wrote is applicable today. I think the biggest difference is that AI enables smaller teams to work on larger systems, and the biggest benefit is for single-person teams (ahem) like me. I see it as another step that allows me to tackle larger systems: the previous one was Clojure which reduced incidental complexity so significantly that I was able to develop the system to the size it is today. AI is the next step: it allows me to build features that would have taken me years in a span of months. Not because of "vibe coding", but primarily because I can work on a set of design documents and turn my ideas into a coherent design.
[1] For the nitpickers: yes, measured, not guessed. Yes, the metric was reasonable. No, it wasn't "lines of code" or something equally silly, in fact one of my main goals is reducing code size as much as possible. Yes, I compared larger time periods: 2 months with AI to an average of 12 months of the previous year. No, the metric wasn't gamed: this is a solo business and I have no interest in gaming my own metrics. I earn a living from this work, so this is as objective as it gets.