Ep. #9, The AI Coding Paradigm Shift with Simon Willison

You know, the firm's focus, the, um, I think a lot of our audience's focus is building better software, and, and even the name of the podcast, High Leverage, just comes from, uh, 'cause it predated, uh, LLMs, which is generally speaking, as software engineers, how can we gain more leverage out of better practices and techniques? And I assume your end of year post from last year had some pretty heady thoughts on that, specifically around software development and applying AI to it.

I mean, the key thing was last year was the year that it, it became indisputable that these things were amazing at code.

Yes.

Right? Like, you could just about argue at the end of 2024 that the code they wrote wasn't very good and was full of bugs, and, and maybe it could slow you down if you didn't know what you were doing with it.

That, that's gone now, and that's because both Anthropic and OpenAI spent basically all of 2025 training for code.

Yes.

Like, Claude Code came out in February of that year.

It quickly became apparent, if you want people to spend $200 a month on your product, code is the thing that they will pay for.

And then there was that moment in November where it was Claude Opus 4.5 and GPT 5.1 came out at the same time, basically, and they were that tipping point where the coding agents got good.

Like, up until then, coding agents were hit-and-miss.

Sometimes they'd be useful, sometimes they weren't.

I'd say that November was the point when a coding agent can now be a reliable partner.

You can use it and know that you're gonna get working code nine out of 10 times, which is pretty great.

You know, now you can use it as a daily driver, and so many of my peers are saying that, yeah, uh, 70, 80% of the code that they produce is now written by coding agents for them.

They'd have laughed at that idea a year ago, and now it's, it's, it's not even surprising to say that.

You know, the firm's focus, the, um, I think a lot of our audience's focus is building better software, and, and even the name of the podcast, High Leverage, just comes from, uh, 'cause it predated, uh, LLMs, which is generally speaking, as software engineers, how can we gain more leverage out of better practices and techniques? And I assume your end of year post from last year had some pretty heady thoughts on that, specifically around software development and applying AI to it.

I mean, the key thing was last year was the year that it, it became indisputable that these things were amazing at code.

Yes.

Right? Like, you could just about argue at the end of 2024 that the code they wrote wasn't very good and was full of bugs, and, and maybe it could slow you down if you didn't know what you were doing with it.

That, that's gone now, and that's because both Anthropic and OpenAI spent basically all of 2025 training for code.

Yes.

Like, Claude Code came out in February of that year.

It quickly became apparent, if you want people to spend $200 a month on your product, code is the thing that they will pay for.

And then there was that moment in November where it was Claude Opus 4.5 and GPT 5.1 came out at the same time, basically, and they were that tipping point where the coding agents got good.

Like, up until then, coding agents were hit-and-miss.

Sometimes they'd be useful, sometimes they weren't.

I'd say that November was the point when a coding agent can now be a reliable partner.

You can use it and know that you're gonna get working code nine out of 10 times, which is pretty great.

You know, now you can use it as a daily driver, and so many of my peers are saying that, yeah, uh, 70, 80% of the code that they produce is now written by coding agents for them.

They'd have laughed at that idea a year ago, and now it's, it's, it's not even surprising to say that.