You have validated your idea and confirmed the problem is real and painful. Now comes the test most founders dread: Does your solution truly fix that problem, in a way people prefer over how they do it today?
This is solution fit, the bridge between discovering a problem and proving your product works well enough that people use it, pay for it, and tell others.
Today, I will break down what solution fit means, what it looks like, how to test it early, and how investors see it.
What is solution fit
Solution fit means you have a product, service, or feature that solves your customer’s pain effectively, better than their current workarounds.
It shows up when:
Early users keep using it after trying it once.
They tell friends or colleagues about it without being paid.
They tolerate early flaws because the core value is that strong.
In short, they would be frustrated if you took it away.
How does solution fit differ from problem fit
Problem fit = You know the pain exists.
Solution fit = You have proven your specific fix works in practice.
Many startups stop at confirming the pain. They launch too soon, with a half-baked product nobody sticks with. It is the reason so many MVPs flop.
Signs you have solution fit
Look for these early signs:
Users complete the core action repeatedly.
Usage grows with minimal push.
Some users ask for improvements or new features (a sign they care).
Users onboard friends or coworkers without being told.
Example:
Slack did not invent workplace chat, but its interface made collaboration so easy that teams stuck with it immediately, and usage grew organically from one team to the whole company.
How to test for solution fit
Launch a simple, usable version. Focus only on solving the key pain point, not on bells and whistles.
Track real usage. Not sign-ups, but actions. Do they come back? Do they invite others? Do they pay?
Interview active users and ask: How would they feel if they could no longer use the solution? If they say indifferent, you do not have solution fit.
Measure engagement, not just acquisition. Usage over time matters more than early hype.
What investors look for
At this stage, VCs want signs of traction. This does not mean huge revenue, but it does mean:
A clear core metric showing repeat usage.
Early word-of-mouth or organic growth.
Evidence that the solution delivers on the promise.
They will ask:
Do customers use it often enough?
Would they miss it if it disappeared?
How hard would it be to switch back?
Common pitfalls
Overbuilding features instead of refining the core solution.
Focusing on acquisition before usage.
Ignoring user churn and assuming it is normal.
Measuring vanity metrics (like downloads) instead of core actions.
Checklist: Do you have solution fit?
Ask yourself:
Is my product solving the main pain?
Do users return without me reminding them?
Is there evidence of word-of-mouth?
Are some users paying, or showing strong intent to pay?
If yes, you are on your way to product market fit. If not, strip back to the basics and fix the real pain first.
Closing thoughts
Finding solution fit is your proof that your product deserves to exist. Without it, growth is forced and expensive. With it, growth is natural.
Take time to get this right, because scaling a product nobody sticks with is the fastest way to run out of money.
Adraudis Santos
Helping founders achieve product market fit
Sources
Rahul Vohra, How Superhuman Built Product-Market Fit
Eric Ries, The Lean Startup (2011)
Y Combinator, How to Start a Startup: Building products users love