Sarah had a problem. Her medtech startup just received 510(k) clearance and closed a $15M Series A. The clinical data for their steerable catheter was unbelievable. Orders were lining up.

But Sarah was staring at an email from the boutique catheter shop that had built every one of her prototypes. “Sorry Sarah, we just can’t get to those 50 units this month. My lead technician is out, and we’re backed up on another job.”

Suddenly, the clinical data didn’t matter. Sarah had nailed it with a supplier who couldn’t scale it. Too big for her boutique shop, too small for the Tier 1 giants.

Most founders treat the supply chain like a checkbox: find a good supplier, qualify them, move on. But your supplier network isn’t a destination. It’s a roadmap. If you don’t plan the transitions, you hit a wall exactly when you should be winning.

Your supplier network has stages. Like your product. #

Loredana Padurean, a professor at Northeastern, uses a framework for startups: Nail it, Scale it, Sail it. Nail product-market fit. Scale without breaking what you nailed. Sail the steady-state business.

The skills that help you nail it — speed, improvisation, doing whatever it takes — are the same ones that break you when you try to scale. Suppliers are no different.

Small suppliers can sometimes grow with you. Large suppliers are like large vessels: built for open water at scale, not for the tight maneuvering a prototype demands.

The shop that takes your sketch and turns it into a catheter in 48 hours is perfect for nailing it. But they likely lack the ISO 13485 rigor to scale it. And the massive OEM supplier with 100 braiding machines won’t answer your email for a 5-unit prototype run.

Stage 1: Nail it (Prototype) #

At this stage, your design is a moving target. You aren’t buying a part. You’re buying iteration speed.

What matters: can the owner pick up the phone at 8 PM? Will they make five parts with a half-finished spec? Do they ask “how can we make this work?” instead of “where is the formal RFQ?” Lowest possible unit price doesn’t matter yet. A $500 prototype part is cheap if it saves you two weeks. A $50 part is expensive if it takes two months.

The trap is over-qualifying. Founders try to do it right by hiring a large supplier for a prototype. They spend three months on a legal MSA only to find out the supplier charges $10,000 for a single design change.

Pick fast suppliers. Pick suppliers who don’t punish you for changing your mind.

Stage 2: Scale it (Clinical / Design freeze) #

The moment you hit design freeze, the game changes. You are no longer iterating. You are validating.

You now need a supplier whose change control runs on documentation, not trust. If you change a dimension, it shouldn’t be a phone call — it should be a formal engineering change order. ISO 13485, lot traceability, material certifications. And headroom: can they go from 5 parts to 50, then 500, without heroics?

The trap is starting too late. A clinical-grade supplier takes 3 to 4 months to qualify. If you wait until you need the parts to start the audit, your launch is already delayed.

Start qualifying the next stage’s supplier while the current stage is still running smoothly.

Stage 3: Sail it (Commercial) #

At commercial scale, excitement is the enemy. You want the most boring supply chain possible.

Unit economics matter now. A part that cost $50 at prototype needs to work at $5 at commercial margins. You need second sources qualified and ready, not just identified. A good test: ask your supplier who their largest customer is. If you’re 80% of their revenue, you’re exposed. If you’re 0.8%, you’ll get bumped when a bigger order comes in.

The trap is assuming the clinical supplier can scale. Many great clinical suppliers hit a ceiling at 1,000 units. Their labor-intensive processes work for clinical batches but fail on commercial margins.

Start the commercial qualification before you need it.

Build the roadmap now #

Don’t wait for a crisis to realize you’ve outgrown your shop. For every critical component, name your nail supplier, your scale supplier, and your sail supplier. Then work backwards: scale supplier qualification should start at least 6 months before design freeze. Sail supplier qualification should start at least 12 months before you expect clearance. Medtech timelines are long enough that “we’ll figure it out when we get there” is always too late.

Padurean’s core insight is that the person who saves the day during nail it is often the bottleneck during scale it. Your job isn’t to find the best supplier. It’s to find the right supplier for the stage you’re entering, while already qualifying the next one.

If you’d rather talk through your specific situation — which suppliers are right for your stage, where you have risk — book a 1:1.

This article appears in the Agile Supplier Field Guide — a strategic guide for pre-Series A medtech founders.