Technology · Language
TypeScript Development
Six shipped sites, zero of them plain JavaScript: TypeScript is the default, not an upsell, because catching a broken prop at compile time is cheaper than catching it in production.
Written by Ing. Hlib Yarovyi, Founder
production sites built entirely in TypeScript, from marketing sites to a 3-language SaaS checkout
Every Next.js site we've shipped — Aurea Sky Tower, Bloom & Bowl, Osvita Poland, Astrooly, Oceania, and a regional law firm site — is TypeScript end to end. On Astrooly, that meant the Stripe pricing logic, the multilingual content types, and the referral attribution model all shared strict types across the codebase, so a mismatched field between the pricing tier logic and the checkout UI fails the build instead of shipping a silent bug to a paying customer.
Where TypeScript Fits
TypeScript isn't a preference we charge extra for — it's the default for every project with real logic in it, because the cost of a type error shows up at a different point depending on whether you catch it. Caught at compile time, it's a red squiggle. Caught in production, it's a support ticket, or worse, a silently wrong price shown to a customer.
That matters most on projects with shared data shapes across many surfaces. Astrooly's pricing logic touches the geolocation lookup, the Stripe session creation, the checkout UI, and the referral commission calculation — four different places that all need to agree on what a 'pricing tier' object looks like. TypeScript makes that agreement enforced, not just documented in a comment someone eventually forgets to update.
The same discipline applies to smaller sites. Aurea Sky Tower's buyer-journey content — floor counts, unit stats, section copy — is typed the same way as Astrooly's payment logic, just with lower stakes. One language, one level of rigor, regardless of project size.
What We Build With It
Strictly Typed Data Models
Shared interfaces for content, pricing, and API responses that keep frontend and backend logic in agreement, catching mismatches at build time instead of runtime.
Type-Safe API Routes
Next.js API routes with typed request and response shapes, so a change to a payload's structure surfaces everywhere it's consumed, not just where it's produced.
Generic, Reusable Component Patterns
Typed React components that enforce correct prop usage across a growing site, reducing the class of bugs that come from a component being used slightly wrong in a new context.
Safer Refactors on Growing Codebases
As a project's scope expands — the way Astrooly grew from a core platform to payments, referrals, and analytics — TypeScript's compiler catches the ripple effects of a change instead of leaving them to be found by testing alone.
Common Questions
- It adds a small amount of upfront structure, but it removes an entire class of bugs — mismatched data shapes between systems — that otherwise get found in QA or production. On a project like Astrooly, where pricing, checkout, and referral logic all had to agree on shared types, that tradeoff pays for itself well before launch.
- Every project. The overhead on a simple site is minimal, and it means there's no point where a growing project has to be retrofitted with types after the fact — which is a much larger and riskier undertaking than starting with them.
- On Astrooly, the pricing tier object is read by the geolocation logic, the Stripe session creation, and the referral commission calculation. A field renamed in one of those without updating the others fails the build immediately — in plain JavaScript, that same change would only surface when a real user hit the affected code path.
- Yes, incrementally — TypeScript is a superset of JavaScript, so files can be migrated one at a time rather than requiring a full rewrite before any benefit is realized.
Need a Codebase That Catches Its Own Mistakes?
We build every production project in TypeScript by default — not as an add-on, but because it's the cheaper way to build once a project has more than a handful of pages. If you have a project in mind, we can scope it clearly.