I replaced a $120/year micro-SaaS in 20 minutes with LLM-generated code

I have been sceptical of the manifold claims that software-as-a-service (SaaS) will be killed by LLMs. The theory behind this idea is:

The reason for my scepticism has been that SaaS such as HR software Workday is more than just software. Workday, for example, keeps up with compliance requirements (e.g., for holiday pay in different countries), guarantees correctness (e.g., payslips that comply with local regulations), and over time the software keeps up to date with changes in the external and internal environments.

However, this week I had first-hand experience of how ridiculously easy it is now to replace SaaS with LLMs. On my website – pragmaticengineer.com – I have a testimonials section, which displays real LinkedIn and X posts about this publication. It cost $120/year for a small service called Shoutout.io, and looked like this:

And this is the backend: nothing fancy, just a way to add, edit, reorganize, and delete testimonials.

I was a customer for four years and logged in perhaps once a year. My latest login was to get an annual invoice for my expenses. Unfortunately, the billing section was broken, so I emailed support and they sent me a broken link instead of the invoice. This was frustrating: why pay for a SaaS with broken billing? I couldn’t even tell what they would charge me next year.

So I asked myself if I could rebuild my own use case with an LLM, and do it rapidly. My use case was much simpler than the SaaS itself:

To my surprise, this whole effort from start to finish took exactly 20 minutes with Codex. The steps I took were straightforward enough:

The end result is visually the same as before, except I no longer have a third-party dependency rendering all of this!

What it means for software engineers:

What this could mean for SaaS software:

“Broken windows” not being fixed is less acceptable than it used to be. My journey away from Shoutout began with its billing system being broken. For example, below is what I saw when I went to my billing section to see the invoices:

As well as this, the customer support sent me a broken link in response to my email. That was enough for me to decide to replace this dependency, and I was surprised by how easy this was with an LLM and knowing what I wanted it to build. By the time customer support sent me a working link two hours later, I had finished migrating off the SaaS.

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