Software Factories and the Agentic Moment

I have been working on my own "Digital Twins Universe" because 3rd-party SaaS tools often block the tight feedback loops required for long-horizon agentic coding. Unlike Stripe, which offers a full-featured environment usable in both development and staging, most B2B SaaS companies lack adequate fidelity (e.g., missing webhooks in local dev) or even a basic staging environment.

Taking the time to point a coding agent towards the public (or even private) API of a B2B SaaS app to generate a working (partial) clone is effectively "unblocking" the agent. I wouldn't be surprised if a "DTU-hub" eventually gains traction for publishing and sharing these digital twins.

I would love to hear more about your learnings from building these digital twins. How do you handle API drift? Also, how do you handle statefulness within the twins? Do you test for divergence? For example, do you compare responses from the live third-party service against the Digital Twin to check for parity?

This is the stealth team I hinted at in a comment on here last week about the "Dark Factory" pattern of AI-assisted software engineering: https://news.ycombinator.com/item?id=46739117#46801848

I wrote a bunch more about that this morning: https://simonwillison.net/2026/Feb/7/software-factory/

This one is worth paying attention to to. They're the most ambitious team I've see exploring the limits of what you can do with this stuff. It's eye-opening.

$100 says they're still doing leetcode interviews.

If everyone can do this, there won't be any advantage (or profit) to be had from it very soon. Why not buy your own hardware and run local models, I wonder.

So much of this resonated with me, and I realize I’ve arrived at a few of the techniques myself (and with my team) over the last several months.

THIS FRIGHTENS ME. Many of us sweng are either going be FIRE millionaires, or living under a bridge, in two years.

I’ve spent this week performing SemPort; found a ts app that does a needed thing, and was able to use a long chain of prompts to get it completely reimplemented in our stack, using Gene Transfer to ensure it uses some existing libraries and concrete techniques present in our existing apps.

Now not only do I have an idiomatic Python port, which I can drop right into our stack, but I have an extremely detailed features/requirements statement for the origin typescript app along with the prompts for generating it. I can use this to continuously track this other product as it improves. I also have the “instructions infrastructure” to direct an agent to align new code to our stack. Two reusable skills, a new product, and it took a week.

Yep, you definitely want to be in the business of selling shovels for the gold rush.

> A problem repeatedly occurred on "https://factory.strongdm.ai/".

Having submitted this I would also suggest the website admin revisit their testing; its very slow on my phone. Obviously fails on aesthetics and accessibility as well. Submitted for the essay.

Relevant blog post from simonw: https://simonwillison.net/2026/Feb/7/software-factory/

(I’m one of the people on this team). I joined fresh out of college, and it’s been a wild ride.

I’m happy to answer any questions!