Insights

What We Refuse to Reuse

What we reuse, what we never will, and why eighteen years is the proof, not the claim.

June 2026 · By Jiwei Zhang, founder of Core70

Every founder who has hired an outside engineering team carries the same quiet worry, even the ones who never say it out loud.

Whatever you learn building my product — how my pricing really works, where my margins hide, the workflow that took me three years to figure out — are you going to turn around and sell it to the company down the street?

It's a fair fear. Most of the industry has earned it.

So let me tell you what we do instead. It starts somewhere that looks unrelated.

The same people, not a revolving door

When you hire a typical shop, you don't get a stable team. People rotate. Someone learns your business. Someone else writes the code. And usually a third keeps the first two talking to each other.

You feel this as handoff. The person who sat in your meetings isn't the person who builds the thing, so half of what you explained evaporates in between. And it evaporates again every time someone new rotates in. You end up re-explaining your own business, over and over, to people who keep leaving.

We don't rotate people off. The same engineer — or, as a relationship grows, the same small core team — sits with you, understands what you are actually trying to do, and builds it. Not a report handed back to developers who never met you. The people who learn your business are the people who write the code.

Years ago one of ours flew to Australia and climbed into the cab of a tractor, because the product he was building was for the people who drive them, and he wanted to understand the work before he wrote a line of code for it. He didn't hand a report back to a developer at home. He was the developer.

That isn't a small team being scrappy. It's the whole point. The thing most models lose to handoff, we never split in the first place.

And here is where the worry comes back

Because if you keep those same people for years — and we do; some of these relationships run a decade or more — then they end up knowing everything. How you make money. What you tried that failed. The shortcut you would never write down.

Which is exactly the thing you were afraid of in the first place.

So I'll be honest about what we reuse, because pretending we reuse nothing would be a lie, and you would see through it.

We reuse the engineer.

Every project makes those people sharper. The judgment, the technical range, the instinct for what is about to break — that compounds, and it travels with them to the next client. That is not a betrayal. It is the upside of keeping good people for years instead of churning juniors. The thing that gets reused is the person, and the person belongs to no one but themselves.

What does not travel is yours. Your business knowhow — the pricing, the margins, the hard-won workflow — stays exactly where it is. We don't fold it into a product. We don't carry it next door. We guard it.

Why you can trust that, when you can't actually check

You are right that you can't verify this. You have no way to audit what an engineer does or doesn't carry into the next engagement. So a promise isn't worth much here. Only evidence is.

The evidence is that the relationships last. One of our core teams has worked with the same UK company for eighteen years — not a rotating cast we keep refilling, but the same people, deepening the same relationship year after year. Another partnership has run a decade. Relationships like that do not survive if the client ever discovers their competitor got the same insight. They survive precisely because that never happens.

Eighteen years is the proof, not the claim.

There is a school of thought — popular in some circles — that the highest form of this work is to take what you learn on the front line and feed it back into your own product, so you can resell that learning to the next ten customers in the same industry. For a company whose asset is a product, that logic holds.

Our asset isn't a product. We don't build software products at all — that is a principle, not an accident. Our asset is people, and the trust they are given. Reusing your knowhow to serve your competitor wouldn't make us more sophisticated. It would make us the exact thing you were afraid of in the first paragraph — and it would destroy the only thing that separates us from ordinary outsourcing.

So: people who understand your business deeply, who stay for years, who get better every year — and who treat what they learn about your company as yours to keep, not ours to resell.

That is the trade. We think it's the right one.

If that's the kind of team you want — people who own the outcome and stay — start small and see how it feels.

A version of this essay was first published on LinkedIn in June 2026.