These two get confused because both come "before the real build." But they answer completely different questions, and using the wrong one wastes time and money. Here is the distinction in plain terms.
The short answer
A proof of concept (PoC) answers one question: "is this technically possible?" A product simulation answers a bigger one: "what is the whole product, and can my team start building it now?" A PoC is a narrow technical test. A product simulation is a complete, runnable foundation, documentation, a working codebase, and a mock database, you own and build forward from.
What a proof of concept is for
A PoC isolates the single riskiest technical assumption and tests just that. Can we process this kind of data at this speed? Can we integrate with that system at all? It is small, often throwaway, and it exists to give you a yes or no before you invest further. If your product depends on something genuinely unproven, a PoC is smart and cheap insurance.
What a PoC is not: it is not the product, it is not reusable, and it tells you nothing about scope, design, cost, or how the whole thing fits together.
What a product simulation is for
A product simulation assumes feasibility is not your main risk (it usually is not) and tackles the real problem: getting from an idea to something complete and runnable. You get the product specified end to end, the architecture designed, the codebase started, and a runnable mock database. It is the foundation your team builds the actual product from.
Which do you need?
- You have a specific technical unknown that could sink the project: start with a proof of concept.
- Feasibility is not really in doubt, and you need the whole product defined and runnable to move forward: you need a product simulation.
- You have both, a risky unknown and the need to move, the feasibility question can be answered as part of building the simulation.
Most founders reach for "let's build a quick proof of concept" when what they actually need is clarity on the entire product. A PoC proves one wire works; it leaves you no closer to a product. A product simulation gives you the whole foundation, and if there is a real feasibility risk, that gets settled along the way.
Not sure which fits your idea? Start a project and you will get an honest read plus a clear, flat-rate scope.
Frequently asked
Is a proof of concept a waste of money?
No, when you have a genuinely risky technical unknown, a proof of concept is the cheapest way to answer it. It is only wasteful when teams build one out of habit for a product that has no real feasibility risk.
Can a product simulation include a proof of concept?
Yes. If your idea hinges on one risky technical question, that can be validated as part of building the simulation, so you get the feasibility answer and a runnable foundation together.