After evaluating technical stacks across AI companies from pre-seed through Series A, certain patterns keep repeating.
Not in every deal. But often enough that they become the first places we look.
These are not always fatal. But they are the kinds of signals that change deal terms, trigger deeper review, or create negotiating leverage before close.
A polished demo is not evidence of a working product. It is evidence of a working demo.
The questions that matter are operational:
A company that has never been in production is a different investment from one that has. The deck usually will not tell you which one you are looking at.
AI is rarely the company. It is usually one layer of the company.
The real question is whether the startup is solving a painful problem with a durable path to customers, and whether AI is improving that motion in a way that matters.
When the pitch centers on the model instead of the problem, it is often because the problem itself is not differentiated enough to stand on its own. That is a strategy issue before it becomes a technical one.
We ask technical founders to walk through the system without the slides.
If the explanation is vague, deferred to a contractor, or inconsistent with the documentation, that is a real signal. Strong technical founders can usually explain:
If they cannot, there is a decent chance they are managing a technical effort they do not fully understand.
“We have proprietary data” is one of the most overused lines in AI pitches.
The real questions are:
Most claimed data moats weaken quickly under that level of scrutiny. Sometimes the data is useful but not unique. Sometimes it is unique but not controlled. Sometimes it is controlled but not actually central to the product’s long-term advantage.
Those are very different situations, and investors should not price them the same way.
Inference costs, storage costs, API rate limits, observability overhead, and engineering headcount all compound faster than many teams expect.
If the technical team has not modeled what the system looks like at 10x current load, then the margin structure investors are underwriting may not survive the next phase of growth.
This tends to show up in:
A lot of early AI companies can grow into a technical economics problem before anyone explicitly names it.
These flags do not always kill a deal.
But every investor should know they are there before committing capital.
Good technical diligence is useful precisely because it surfaces these issues while there is still time to change terms, ask harder questions, or walk away with a cleaner understanding of the risk.
Technical Due Diligence
Arc5 delivers a written diligence report and live debrief in 48 to 72 hours for investors who need a fast, independent view on product, code, AI claims, and execution risk.