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Senior engineers
In your repo and standups.
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Monthly terms
Stop with 2 weeks' notice.
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No hiring process
No recruiters. No notice periods.
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You own the code
100% of the IP, day one.
To hire TypeScript developers in 2026, look for seniors who run strict mode, validate data at runtime with a schema library such as Zod, share types between API and client, structure monorepos with workspaces and migrate JavaScript incrementally. Yarify gives you senior TypeScript engineers on monthly terms with 2 weeks' notice, or fixed-price migrations. Senior market rates run about $60–80 per hour in Central Europe and $140–200+ in the US.
What strict TypeScript buys you
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Refactors in hours
Not a week of careful clicking.
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Faster onboarding
New hires read signatures, not minds.
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Fewer shape bugs
Missing fields fail in CI.
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Fast type checks
Cached builds, native compiler ready.
What our TypeScript developers deliver
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End-to-end types
One schema types the API, validates requests and types the client. A renamed field fails the build.
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Runtime validation
Webhooks, forms, env variables and third-party APIs parsed with Zod or Valibot. Bad data stopped at the door.
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Monorepos that stay fast
pnpm workspaces, Turborepo or Nx, shared packages for types, UI and config.
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Types that model the domain
Discriminated unions for draft, paid, refunded. Branded IDs. Exhaustive switches that fail the build.
A JavaScript-to-TypeScript migration, without a freeze
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Read the repo · Week 1
A call, then a look at the code. We tell you whether a migration is worth it.
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Plan in writing · Week 1–2
Riskiest folders first, tsconfig targets, CI gates, what stays JavaScript for now.
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Convert in slices · Ongoing
Each pull request converts a module and tightens one rule. Your team keeps merging features.
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Hand over guardrails · Handover
Strict mode on, a lint rule for new any, written conventions. It stays typed after we leave.
Hiring takes months. We start building.
Hiring a developer
- Job post & sourcing
- Interviews
- Notice period
- Onboarding
- Building
Yarify
- Call + fixed quote
- Building + weekly demos
- Live. Iterating with users.
Illustrative timeline. In-house hiring usually spends months on sourcing, interviews and notice periods before the first commit.
Hallmarks of a senior TypeScript developer
- Uses unknown for untrusted data and narrows it
- Derives types from runtime schemas, not the other way round
- Models states with discriminated unions and exhaustive checks
- Has migrated JavaScript incrementally, not in one giant branch
- Knows when a generic adds clarity and when it adds a puzzle
- Writes types a mid-level developer can read
Interview questions for TypeScript developers
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any or unknown: when do you use each?
unknown forces narrowing. Every any is debt with a written reason.
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How do front end and API agree on a shape?
Shared schema, generated OpenAPI client or tRPC, plus runtime validation for old deployed servers.
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We have 400 JS files. Plan the migration.
Incremental, risky modules first, CI gates that only tighten, no feature freeze.
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Our type check takes four minutes. Now what?
Project references, incremental builds, isolating heavy generics, CI caching, the native compiler.
TypeScript developer rates by region
Hourly market bands from industry surveys. Not our price list: we quote after a free call.
| Region | Junior | Mid-level | Senior |
|---|---|---|---|
| United States | $70–100 | $100–140 | $140–200+ |
| Western Europe | $55–80 | $80–110 | $110–160 |
| Central & Eastern Europe | $30–45 | $45–60 | $60–80 |
| Latin America | $35–50 | $50–65 | $65–90 |
| South & Southeast Asia | $20–32 | $32–42 | $42–55 |
TypeScript doesn't move the band much. Seniority does. A senior CEE month is about $9.6k–12.8k. See software developer rates.
Monthly, or one fixed price.
Augmentation bills monthly with 2 weeks' notice. A scoped migration can be a fixed quote: if our estimate was wrong, the extra hours are our cost. Your code and IP from day one.
- Works in your repo and CI
- No long contract, no exit fee
TypeScript products we shipped
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Astrooly: Paid SaaS in Three Languages
Multilingual astrology SaaS: natal chart engine, AI-assisted readings, Stripe checkout in 3 languages with country pricing, server-side referral attribution, admin dashboard, GTM analytics.
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Cold Outreach That Stays Out of Spam
Custom cold outreach and email campaign platform: multi-step sequences, SPF/DKIM/DMARC checks, inbox warm-up and rotation, LLM-personalised first lines, reply detection and campaign analytics.
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Osvita Poland: Admissions Made Clear
Ukrainian-first, mobile-first admissions site for a study-abroad consultancy. Five-step process, consultation form above the fold, Next.js and TypeScript, live in four weeks.
Questions buyers ask us
How much does it cost to hire a TypeScript developer?
Industry surveys put senior developers at about $60–80 per hour in Central and Eastern Europe, $110–160 in Western Europe and $140–200+ in the US. A senior CEE month is roughly $9.6k–12.8k. We quote monthly or fixed-price after a free call.
Is migrating from JavaScript to TypeScript worth it?
For a product you'll change for years, usually yes: safer refactors, faster onboarding, fewer data-shape bugs. For a small app that's nearly finished, often not. Done incrementally, it never needs a feature freeze.
How long does a JavaScript-to-TypeScript migration take?
It depends on size, test coverage and how strict you want to end up. Small apps convert in a few weeks of part-time work; large codebases over months, alongside normal development. We scope it in writing first.
Front end or backend TypeScript?
Both. Our engineers write TypeScript in React and Next.js front ends and Node.js backends. The biggest wins come from sharing types between the two.
Can you set up a monorepo for our apps?
Yes. Typically pnpm workspaces with Turborepo or Nx, shared packages for types, UI and config, and CI that rebuilds only what changed. Conventions are written down so the structure survives the next ten hires.
What are the contract terms?
Monthly billing, cancel with 2 weeks' notice, no long lock-in. You own all code and IP from day one. Fixed-price migrations carry our guarantee: overruns on our own estimate are our cost.
Keep reading
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Staff augmentation
Senior engineers embedded in your existing team: your repo, your standups, your tracker. Monthly billing, 2 weeks’ notice, and every line of code is yours.
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Dedicated development team
A dedicated development team of 2–4 senior engineers working on your product. Monthly billing, cancel with 2 weeks’ notice, 100% of code and IP is yours.
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Augmentation vs dedicated team
Staff augmentation or a dedicated development team? Who manages the work, who owns delivery, monthly costs and a clear rule for choosing, with an illustrative example.
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Developer rates by country
Hourly software developer rates by country and seniority in 2026: US, Western Europe, Central & Eastern Europe, Latin America and Asia, with monthly costs and freelance benchmarks.
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Node.js developers
Senior Node.js engineers for APIs, queues, integrations and observability on NestJS, Fastify, Postgres and MongoDB. Join your team monthly or take a fixed-price backend build.
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Next.js developers
Senior Next.js engineers for App Router builds, Pages Router migrations, caching and SEO fixes, Stripe and auth. Join your team monthly or own a fixed-price build.
Make the compiler catch it first
30 minutes with a senior TypeScript engineer. Bring your tsconfig and your worst bug.