About SoloStack — Reviews From Someone Who Builds AI

SoloStack exists for one reason: there are now thousands of AI tools, most of them oversold, and a one-person business doesn't have time to test them all. I do that testing and report back in plain English — what a tool is genuinely good at, where it falls short, and whether it's worth the money for someone running solo.

Who writes this — and why it's different

I'm PJ Geldenhuis, and I don't just review AI tools — I build with them. Most "best AI tools" lists are written from press releases and affiliate payouts. Mine come from someone who ships real products on top of these models, runs into their limits, and pays the API bills.

In my own time I design, build, evaluate, and operate production AI systems solo — shipped across web, native iOS, and SMS:

DoorOps — an AI property-operations platform running live on a real rental portfolio, where a language model drives real workflows through a tightly constrained, fully audited set of actions that fail closed when something can't be verified.
Lumenor — a Socratic AI tutor whose every release is gated by a 61-scenario evaluation harness that red-teams it for jailbreaks and answer leaks before it can ship.
Tiglit — a native iOS parenting app whose Story Studio orchestrates three different AI providers behind one resumable generation pipeline with hard spend limits.

The full engineering write-ups — architecture, safety boundaries, live evaluation reports, and named artifacts — are on the portfolio. That's the lens I bring to every review here: not hype, but hands-on judgment about whether an AI tool actually earns its place in real work.

Why that matters for you: I evaluate tools the way I evaluate them in my own builds — against real tasks, with an eye for hidden cost, reliability, and whether the AI genuinely pulls its weight. No tool-of-the-week hype.

How I test

Real tasks, not demos. Tools get judged on the everyday jobs of a solo business: writing, summarizing, research, email, scheduling, and bookkeeping-adjacent admin.
Total cost honesty. I flag free tiers, hidden limits, and the price after the trial ends.
I say "skip it." If a tool is hype, I'll tell you. A review that recommends everything is useless.

Who this is for

Freelancers, creators, side-hustlers, and small-business owners of one. If you're trying to punch above your weight with a tiny budget and no team, you're in the right place.

A note on independence: some links on this site are affiliate links, which means SoloStack may earn a commission if you sign up through them — at no cost to you. That never changes my verdict. See the disclosure for details.

Have a tool you want tested, a build you want to talk shop about, or a workflow you're stuck on? Get in touch — reader questions shape what I cover next.