Every studio says it builds software that’s “typed and tested.” It sounds like jargon — two boxes engineers tick to feel professional. It isn’t. Typing and testing are the two cheapest forms of insurance you can buy on a product, and the payoff lands exactly when it hurts most: the day you need to change something.
What “typed” means for you
A type is a promise the code makes to itself: this is a price, in cents, never empty. This is a user, and a user always has an email. When everything is typed end to end, the computer checks those promises every time anyone touches the code — before it ever reaches a customer.
The benefit isn’t fewer typos. It’s that whole categories of bugs become impossible to ship. The classic “undefined is not a function” crash, the checkout that breaks because a field was renamed, the report that silently shows the wrong number — those mostly come from one part of the app assuming something another part stopped guaranteeing. Types catch that mismatch the moment it’s written, not three weeks later in a customer’s hands.
What “tested” means for you
A test is a tiny robot that uses one corner of your product the same way every time and shouts if the answer changes. Write one for “a discount code takes 10% off,” and from then on, nobody can quietly break discount codes without the robot noticing first.
The value compounds. A product without tests gets more fragile as it grows — every new feature is a chance to break an old one, and you find out from users. A product with tests gets safer to change, because the robots stand guard over everything that already works. That’s the difference between a codebase you’re afraid to touch and one you can keep shipping into for years.
The real payoff: speed, later
Here’s the part that gets missed. Typing and testing feel like they slow the first version down — a little upfront discipline instead of racing to a demo. And on day one, yes, a sloppy build can look finished faster.
But software’s cost isn’t day one. It’s every change after. The untyped, untested build is quick to start and brutal to evolve: each new feature risks the last, every fix spawns two bugs, and eventually the honest recommendation is a rewrite. The typed, tested build is a touch slower to start and stays cheap to change for as long as you own it.
We build typed and tested by default, even for an MVP, because the whole point of an MVP is to learn fast and change fast. A foundation you can’t change safely defeats the exercise.
What to ask any studio
You don’t need to read the code to check this. Ask three questions:
- Is it typed end to end? (The answer should be yes, with TypeScript.)
- Is there an automated test suite, and does it run before every deploy?
- If I want to change something in six months, what stops it from breaking everything else?
If the answers are vague, the bill for that vagueness arrives later — with interest. Cheap to build and expensive to own is a bad trade. Typed and tested is how you avoid it.