Off-the-Shelf to Prove It, Custom to Ship It
Prototype with whatever works fastest; go custom only when KPIs demand it.
- Difficulty
- Moderate
- Time to result
- ~weeks to results
- Steps
- 3
- Confidence
- 90%
A recurring hardware decision is whether to use cheap existing components or build something new. Kalinowski's rule: in prototyping, use off-the-shelf parts aggressively because the only goal is proving the thing can work at all; reserve custom parts for mass production, and only where an off-the-shelf part can't meet a specific KPI. The bridge is a 'works like / looks like' pairing that keeps the ugly working prototype tethered to the final industrial design.
Origin
Caitlin Kalinowski, on component strategy across VR and consumer hardware.
Core principles
- 01The purpose of a prototype is to show it can work at all, not to be pretty or final
- 02Speed of proof beats elegance in the prototyping phase
- 03Custom parts are justified only when a KPI (size, weight, color) can't be met off-the-shelf
- 04A prototype must stay checkable against whether it can fit the final industrial design
How to run it
- 1
In prototyping, grab whatever works fastest
Use off-the-shelf parts wherever you can to reach a working prototype quickly. The goal is a proof of function — 'can you get a thing working' — even if it's the ugly version.
- 2
Keep a 'works like' and a 'looks like' model in parallel
Pair a working (ugly) prototype that proves function with an industrial-design model that shows the final form. Humans reason well across the two as long as what you've proven can plausibly fit into the final design.
Pro tip Continuously sanity-check that the off-the-shelf parts' size, weight, and materials could actually shrink into the final industrial-design envelope.
Watch out For younger companies the working parts often can't fit the intended form — if you never check, you prove the wrong thing.
- 3
Go custom in production only where a KPI forces it
At mass production, still buy off-the-shelf if a stock part fits your size/weight/color targets. Choose custom when stock parts, though functional, aren't exactly right for your goals.
Watch out Custom parts add cost, lead time, and supply-chain risk — don't default to them when a stock part meets the KPI.
In the wild
Kalinowski notes drones are now cheap precisely because so many components were innovated, scaled, and mass-manufactured for other uses; builders can assemble a capable drone from those existing parts rather than designing everything custom.
→ Dramatically lower cost and faster assembly by leveraging the off-the-shelf ecosystem instead of bespoke components.
Common mistakes
Polishing a prototype instead of proving function
Spending prototype time on making parts final or pretty misses the phase's only job — showing it can work at all — and slows the proof.
Prototyping with parts that can't fit the final form
If the off-the-shelf demo can't physically shrink into the industrial design, you've validated something that won't translate to a shippable product.
Is it for you?
Best for
Hardware teams and startup founders deciding build-vs-buy while racing to a working proof
Not ideal for
Products whose entire differentiation is a novel custom component that has no off-the-shelf analog even for prototyping
From the transcript
“I use offtheshelf whenever I can especially in the prototyping phases”
“your goal is to show that it can work at all”
“we call it works like looks like models”
From the episode
Why we’re at the beginning of the AI hardware boom
Caitlin Kalinowski (ex–OpenAI, Meta, Apple)