any epidemic in legacy bases
Implicit any from JS migration and explicit any shortcuts accumulate until the type system provides no safety. We track any count per module and require it to decrease per PR.
Strict mode End-to-end types OpenAPI GDPR
TypeScript Engineering Services for Type-Safe Production Systems
Every greenfield project at YuSMP defaults to strict TypeScript across front and back. We pair Zod at API boundaries, generate types from OpenAPI specs, enforce type coverage as a CI gate, and run tsc --noEmit as part of every PR check. Thirty-plus production systems — Signatory Pro's e-signature platform, ArgoView's clinical workstation, ANT's PropTech marketplace — all type-safe end-to-end.
We deliver TypeScript engineering for SaaS and fintech teams migrating JavaScript codebases to strict TypeScript, product teams building new end-to-end typed stacks with React, Next.js and NestJS, platform teams designing monorepo type-sharing infrastructure, and regulated industries where type safety at API boundaries is a risk-reduction requirement. Type coverage is a CI gate, not a code review suggestion.
Challenges
Industry challenges we solve
Mismatched FE/BE contracts
Frontend types diverging from backend responses produce runtime crashes that TypeScript cannot catch. We generate frontend types from OpenAPI specs or use tRPC for zero-divergence contracts.
Slow tsc builds in monorepos
TypeScript build times on large codebases exceed 10 minutes without project references. We configure tsconfig references for incremental builds and add remote cache via Turborepo.
Library typings drift
Third-party @types packages lag behind library versions, causing compile errors after upgrades. We pin @types versions alongside library versions and review them together.
Generics misuse increasing complexity
Overengineered generics produce error messages no one can parse and types no one can understand. We prefer readable inferred types over explicit generics where the inference is obvious.
Runtime vs compile-time validation gap
TypeScript only validates at compile time — network payloads, environment variables and config files are unknown at runtime. We add Zod validation at all system boundaries.
Solutions
Solutions we build
Strict-mode migrations
Incremental enabling of strict TypeScript on JavaScript or loose TS codebases — with type-coverage tracking and a PR ratchet that prevents regression.
Monorepo type-sharing
Turborepo or Nx monorepos with shared types packages, project references for incremental builds and eslint-plugin-import boundary enforcement.
OpenAPI → TS codegen pipelines
OpenAPI spec-first development with orval or openapi-typescript generating typed API clients — updated automatically on spec change.
End-to-end typesafe APIs (tRPC)
Full-stack TypeScript with tRPC — no API client generation, instant type propagation from backend router to frontend query hook.
Zod boundary validation
Runtime validation at all system boundaries — HTTP request bodies, environment variables, config files, LLM structured outputs — with TypeScript inference from schema.
Type-aware code reviews
ESLint rules for no-explicit-any, no-non-null-assertion, type-coverage thresholds and import constraints — enforced in CI, not just style guides.
Stack
Technology stack
TypeScript 5.7, Zod, tRPC, openapi-typescript, orval, Turborepo, Nx, ESLint, Prettier, Vitest, Playwright, ts-node, tsx.
Compliance
Compliance & regulations
GDPR-aligned · WCAG 2.2 AA · SOC 2-capable · HIPAA-capable · CCPA-acknowledged
EU
- GDPR — type-safe DSR automation and consent state management.
- EAA 2025 — typed accessibility component APIs.
- CRA — typed SBOM generation and secure SDLC gates.
- eIDAS — typed identity token handling.
US
- WCAG 2.2 AA — typed accessibility primitives and axe-core integration.
- CCPA/CPRA — typed consent state and opt-out flows.
- SOC 2 — type-safe audit log schemas and event typing.
- HIPAA — typed PHI handling and minimum-necessary access controls.
Shared: OWASP ASVS L2, typed input validation with Zod, SBOM per build.
Cases
Selected TypeScript case studies
LegalTech · Mobile · CRM
Signatory Pro
Native iOS and Android e-signature clients with a Symfony + React CRM for a cross-border law firm — KYC onboarding and a defensible evidence trail for US & EU matters.
HealthTech · Endoscopy
ArgoView
Tablet-first endoscopy recording, patient records, and DICOM/HL7 export — built on Laravel + React with browser-tier WebRTC capture for US & EU clinics.
PropTech · Marketplace
ANT
Property marketplace web platform with listing CMS, search and B2B admin console for US and EU operators.
Why YuSMP
Why TypeScript teams choose YuSMP
Strict mode by default
We start every project with strict: true and no-explicit-any enforced. Type safety is a delivery requirement, not a style preference.
Cross-stack typing expertise
React front-ends, NestJS backends, React Native apps — all typed end-to-end with shared type packages or tRPC. No contract drift across the stack.
Codegen pipeline experience
OpenAPI → TypeScript client generation wired into CI — frontend types update automatically when the API spec changes.
FAQ
TypeScript FAQ
How do you share types between the frontend and backend?
Monorepo with a shared types package (Turborepo or Nx) for manual type definitions, or OpenAPI codegen (openapi-typescript or orval) to generate TypeScript clients from your API spec automatically. tRPC for teams that want end-to-end type safety without a schema intermediate. The right choice depends on whether you control both ends of the API contract.
Strict mode — should we enable it on an existing codebase?
Yes, but incrementally. Enable strict: true with ts-ignore-count suppression tracking — measure the suppression count per PR and require it to decrease or stay flat. Never increase it. Typically 8–16 weeks to zero suppressions on a mid-size codebase with deliberate effort.
Zod or io-ts or class-validator — which do you use?
Zod is our default for new TypeScript projects — runtime validation, TypeScript inference from schema, excellent error messages, works in browser and Node. class-validator for NestJS applications where decorator-based validation integrates cleanly with the framework. io-ts for functional programming teams using fp-ts who want category-theory-aligned codecs.
How do you enforce type coverage in CI?
type-coverage npm package reports the percentage of typed expressions per file. We gate on a minimum coverage threshold (typically 95%+) in CI and block PRs that reduce coverage. Combined with strict mode and no-explicit-any ESLint rule, this creates a ratchet — coverage can only improve.
tRPC or REST+OpenAPI for a new project?
tRPC for full-stack TypeScript monorepos where both client and server are in TypeScript and you want instant type safety without code generation. OpenAPI for projects with multiple consumers (mobile apps, third-party integrations), language-heterogeneous stacks, or existing API contracts you must maintain.
How do you approach TypeScript in a monorepo?
Project references (tsconfig references) for incremental builds — only changed packages rebuild. Turborepo or Nx for build orchestration with remote caching. A root tsconfig.base.json with strict settings that all packages extend. Package boundaries enforced with eslint-plugin-import or Nx constraints.
Ship type-safe products with senior TypeScript engineers
Response within 1 business day. NDA on request.