A guide to prototype development for startups

By Dr Nicola Wheeler-Thorn, Managing Director of ANDtr

Startups often burn through time and money chasing ideas that haven’t been validated. A prototype is the antidote. Rapid prototyping shortens feedback loops, reduces cost and risk, and helps founders learn faster. This guide is everything you need to know about prototype development – from early sketches to production readiness – so you can build a product that will genuinely scale.

A prototype for startups is a tangible representation of an idea. It’s a way to see if a product will actually work and can scale in the long run. Prototypes are not just mini-products; they’re learning tools to validate problems, test usability, demonstrate feasibility, and eventually secure funding.

 Prototypes can range from low-fidelity sketches to high-fidelity models. Fidelity simply means the level of detail and functionality that a prototype offers. For example:

•  Low-fidelity prototypes: quick sketches, paper mockups, or wireframes.
• Medium-fidelity prototypes: clickable digital prototypes or foam models.
• High-fidelity prototypes: functional hardware boards or polished digital builds.

Choosing the right fidelity depends on the stage, resources, and whatever risk a founder is trying to reduce. For example, if the risk is “will clinicians understand how to set up our medtech sensor?”, a medium-fidelity prototype with a basic enclosure and simulated device interface can confirm the workflow before investing in real hardware.

All innovators will go through low, medium and high-fidelity modes during the entrepreneurial journey – and often back again. There could be many iterations. 

•  Low-fidelity is best for early validation of ideas. Think cheap, fast, and disposable. Anything from sketching your idea on a napkin to paper mock-ups, wireframes.
• Medium-fidelity is for usability testing and refining the user experience. It’s not a polished product, but it is usable.
• High-fidelity prototypes are essential for investor demos, pilot tests, and technical validation. It’s where founders will understand if their product will scale.

The following guide outlines the key points every innovator should consider when it comes to prototype development. It’s not a rigid step-by-step guide because the exact order will depend on the product and founder, but all should take place at some point. 

 Maximise output vs resources

This is what prototype development is all about – making the most progress with the time and money available. Prototypes for startups must maximise the output vs resources trade-off, which means picking the high-impact experiments that give innovators the most insight for the least effort. 

For example, for Arqiva, ANDtr built prototype DAB radio transmission units using breadboard circuits and basic PCB layouts to test functionality before committing to full-scale manufacturing. Focus on the work that moves an idea forward, not just more work.

Concept sketches

It all starts with a vision. Generate multiple concepts in quick sketches or storyboards to explore interaction patterns and system boundaries. Keep the sketches focused on the user goals and failure modes you want to expose. Narrow to one or two concepts that best map to your riskiest assumptions.

 Research and requirements

Conduct market research, competitive audits, and regulatory checks to flag non-starters before you prototype. Think: applicable standards, safety classes, or required certifications. Founders should be able to answer: is there a market for this product? Is it actually doable? For medtech especially, include clinical stakeholders and risk-management requirements from day one.

Build a low or medium-fidelity prototype

Use paper mockups, clickable screens, foam models, or breadboards to test desirability and core interactions without committing to production hardware. Tools like Figma or Balsamiq for UI (user interface) flows, and Arduino or off-the-shelf dev boards for hardware proofs, let you simulate behaviour quickly.  

Build functional prototypes

There are a myriad of options for rapid prototyping. Startups should move to quick-turn PCBs, modular off-the-shelf modules, and 3D-printed housings that mimic the final form factor while keeping BOM (bill of materials) complexity low. Focus on the reliability of the core subsystems and document firmware interfaces and failure modes. A clear functional prototype helps you answer manufacturability, performance, and realistic cost questions for investors and partners.

Test and iterate

Run usability tests, lab experiments, and field trials. Iteration is where prototypes deliver their real value. This can and should be done throughout the journey – iteration at low or medium-fidelity prototypes is just as important as high-fidelity.

Prioritise production readiness

Introduce Design for Manufacturing (DFM) to avoid expensive tooling, yield loss, or long lead times. Industry and academic programs emphasise that early DFM alignment eliminates rework and reduces downstream delays. 

 Pilot runs

Run a small-batch pilot (often called a Pilot Production or Production Validation Test) to validate yields, cycle time, test fixtures, and documentation. Use the pilot to update the BOM, fix supplier single-point failures, validate quality tests, and collect field reliability data. Pilots are the last fast feedback loop before mass production. 

Prototype development is rarely a straight line, and that’s all part of the learning process. However, founders should take care to avoid the following that waste time, money, and credibility.

• Over-engineering too soon: Don’t sink time into polished builds before testing basics. Start lean, validate fast.
• Skipping user feedback: Internal opinions aren’t enough. Test even rough mockups with real users and industry experts as soon as possible.
• Neglecting compliance: In regulated sectors, late-stage surprises kill timelines. Bake standards in from day one, especially in the case of medtech.
• Single-source dependencies: One supplier = one bottleneck. Line up alternatives before you scale.
• Confusing prototype with product: A prototype proves feasibility, not readiness. Pitch it to investors as evidence, not the finished thing.

Accelerators compress the messy middle of prototyping into a structured sprint. Here’s the edge they give:

• Expert guidance: Mentors in design, engineering, and manufacturing help you dodge rookie mistakes.
• Structured milestones: Deadlines force progress from sketch to functional build without endless tinkering.
• Practical resources: Shared labs and tools mean you can test without heavy upfront investment.
• Investor visibility: Showcase prototypes in front of investors and partners at the right stage.
• Supplier networks: Tap into vetted manufacturers and service providers to smooth pilot runs.

This is exactly what The Embedded Accelerator by ANDtr strives to do. Follow us on LinkedIn for updates and info about our next application round.

Dr Nicola Wheeler-Thorn is the Managing Director of ANDtr, working with embedded electronics startups and spin-outs. Nicola has deep knowledge of cutting-edge technologies and commercialisation; she is a thought leader in the space, regularly speaking at events and contributing to publications such as New Electronics and Raconteur. Nicola holds a PhD in Mathematics, sits on the University of Essex Enterprise Board, and is a UK National BSI Committee member for medical devices. You can find her on LinkedIn here.

• What is prototype development? It’s the process of building testable versions of your product idea to validate assumptions.
• How long does prototype development take? It can take anywhere from weeks (for low-fidelity) to months (for functional prototypes), depending on complexity.
• How can I get help with prototype development? Programs like The Embedded Accelerator by ANDtr provide practical advice and tools to make product prototyping less risky. 
• When should startups engage manufacturers? As soon as you have a functional prototype and a clear DFM checklist. Early engagement avoids costly redesigns.