A/B testing: what it is, how to do it right, and mistakes that ruin your tests
A/B testing compares two versions of an element to determine which converts better. Learn the correct methodology, common mistakes, and how to scale your...

A proof of concept (PoC) is a small-scale demonstration whose goal is to verify that an idea, concept, or technology is viable before investing significant resources in its development. It's not a product. It's not a functional prototype. It's the answer to a fundamental question: can this work?
The most frequent mistake in both the startup and corporate worlds is the same: building before validating. According to CB Insights, 35% of startups fail because there's no market demand for their product. Not because the product is bad, but because nobody asked for it. A well-executed PoC eliminates (or at least reduces) that risk before it gets expensive.
In this guide, we'll explain what a proof of concept is, when it makes sense to use one, how it differs from an MVP and a prototype, and how to design one step by step to validate your idea with minimum effort and maximum learning.
A proof of concept is a validation exercise that answers the question: "Is this technically and conceptually possible?" It focuses on proving viability, not on building a functional product.
Characteristics of a good PoC:
Examples of PoCs in different contexts:
| Context | Hypothesis to validate | PoC | Duration |
|---|---|---|---|
| SaaS Startup | Would users pay for this feature? | Landing page + interest form | 1 week |
| Ecommerce | Does our recommendation engine improve AOV? | Test with 5% of traffic for 2 weeks | 2 weeks |
| Industrial company | Can we automate visual inspection with AI? | Model trained with 500 real images | 3 weeks |
| Fintech | Does blockchain reduce settlement time? | Simulation with 100 transactions on testnet | 2 weeks |
These three concepts are constantly confused. They are different tools with different objectives:
| Concept | Objective | Audience | Development level | Expected outcome |
|---|---|---|---|---|
| PoC | Validate viability | Internal team, investors | Minimum (can be manual) | Evidence that it works |
| Prototype | Explore the experience | Potential users | Medium (interactive UI, no backend) | Feedback on UX/UI |
| MVP | Validate market demand | Real users | Functional (minimum real product) | Usage and payment data |
The logical flow is: PoC → Prototype → MVP. But you don't always need all three. If technical viability is obvious (similar solutions already exist in the market), you can skip straight to the MVP. If the question is about user experience, a prototype is sufficient.
The key is not building an MVP when what you need is a PoC. An MVP requires code, infrastructure, and time. A PoC can be done with a spreadsheet, a Google form, and a week.
If your idea depends on technology you haven't tested (AI, blockchain, legacy system integration, real-time processing), a PoC verifies it works before committing development resources.
In corporate environments, a PoC is the tool for moving from "I think this could work" to "look, it works." With investors, it reduces perceived risk. With executives, it justifies the budget.
If building the full product costs €200,000 and 6 months, a €5,000, 2-week PoC that validates (or invalidates) the core hypothesis is the smartest investment you can make.
Should we use the OpenAI API or train our own model? PostgreSQL or MongoDB for this use case? A PoC for each option gives you data to decide, not opinions.
A PoC without a clear hypothesis is an experiment without an objective. Formulate your hypothesis precisely:
Define before starting what result you need to consider the PoC successful:
Without predefined criteria, any result can be interpreted as positive. That's confirmation bias, not validation.
The PoC should test the minimum necessary to validate the hypothesis. If your idea is a marketplace platform with 50 features, the PoC doesn't test all 50. It tests the most critical one: are sellers willing to list products? Are buyers willing to pay?
Set an immovable time limit: 1 week, 2 weeks, maximum 4. If the PoC needs more time, you're probably building more than a PoC.
The PoC can yield three outcomes:
The most valuable outcome of a PoC isn't "it works," but "we know exactly what works and what doesn't." That information is worth more than months of blind development.
A visual framework for planning your PoC on one page:
| Element | Description | Your PoC |
|---|---|---|
| Hypothesis | What do you want to prove? | (Complete) |
| Success criteria | How will you know it works? | (Complete) |
| Scope | What's included and what's NOT? | (Complete) |
| Resources | People, tools, data | (Complete) |
| Duration | Maximum in days or weeks | (Complete) |
| Risks | What could go wrong? | (Complete) |
| Decision | What will you do based on the result? | (Complete) |
1. Turning the PoC into an MVP. The most frequent mistake. The PoC grows, features get added "since we're at it," and you end up with a half-baked product instead of a clear validation. Discipline.
2. Not defining success criteria before starting. If you define success after seeing the results, you're cherry-picking, not validating.
3. Using unrealistic data. A PoC with perfect test data validates nothing. Use real data, with its noise, exceptions, and problems. That's what you'll find in production.
4. Not involving users. If the PoC is validating a user-facing solution, you need real feedback from real users. Not from the internal team, not from friends — from users in the target segment.
5. Ignoring the negative result. A PoC that proves something DOESN'T work is just as valuable as one that proves it does. It saves you months and money. The problem is when ego or corporate politics won't allow accepting a negative result.
6. Not documenting learnings. Whether the PoC works or not, document what you learned. That information is capital for future decisions.
The proof of concept fits naturally within the Lean Startup methodology. In the Build-Measure-Learn cycle, the PoC is the cheapest possible "Build" tool:
The goal isn't to be right. It's to learn fast and cheap. If the PoC invalidates your hypothesis in 2 weeks, you just saved 6 months of development and €100,000+ in investment.
A PoC doesn't validate product-market fit. It validates viability. But it's a necessary step toward PMF:
Jumping from PoC to scaling without going through MVP and PMF is the recipe for failure. Each phase validates a different layer of risk.
Before building anything, Drew Houston created a 3-minute video showing how Dropbox would work. Signups went from 5,000 to 75,000 overnight. The PoC wasn't technical (the sync technology already existed). It was about demand: do people want this?
Nick Swinmurn didn't build an ecommerce site. He went to shoe stores, photographed products, and listed them on a basic website. When someone bought, he went to the store, purchased the shoe, and shipped it. The PoC validated that people would buy shoes online.
The Google Glass PoC worked technically: the glasses did what they promised. But the PoC didn't validate social acceptance. People didn't want to wear cameras on their faces. The technical PoC succeeded; the market PoC failed. Lesson: validate all dimensions of risk.
| Type of PoC | Typical duration | Estimated cost | Resources |
|---|---|---|---|
| Landing page + form | 3-5 days | €0-500 | 1 person |
| Clickable prototype | 1-2 weeks | €500-2,000 | 1-2 people |
| Technical integration | 2-3 weeks | €2,000-10,000 | 1-2 developers |
| AI model | 2-4 weeks | €3,000-15,000 | 1 data scientist + data |
| Hardware/IoT | 4-8 weeks | €5,000-30,000 | Multidisciplinary team |
If your PoC exceeds 4 weeks or the allocated budget, you're probably not building a PoC.
The proof of concept is the most efficient tool for reducing risk before investing. It's not a luxury or a bureaucratic step: it's the difference between building something nobody wants and building something you already know works.
The discipline is not falling in love with the idea and letting the data speak. A failed PoC is a learning success. A successful PoC is the green light to invest with confidence.
If you want to validate that your website or digital product is converting to its full potential, at Boost we apply the same validation rigor to every CRO experiment. Learn about our optimization services or run a quick diagnostic with Scan&Boost.
Adrià Vidal is the founder of Boost. +1,000 optimization actions, +47.8% average conversion uplift per client, +€7.8M in additional revenue generated.
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