TypeScript Modernization Services
Transform your JavaScript codebase into type-safe, maintainable TypeScript. Reduce bugs, improve developer experience, and accelerate development.
Why Migrate to TypeScript?
Catch Bugs Before Production
TypeScript catches type errors, null references, and API mismatches during development, reducing runtime errors by up to 40% according to industry studies.
- Compile-time error detection
- Null/undefined safety
- API contract enforcement
- Refactoring confidence
Improve Developer Experience
Modern IDEs provide exceptional autocomplete, refactoring tools, and inline documentation with TypeScript, boosting productivity by 20-30%.
- IntelliSense autocomplete
- Safe automated refactoring
- Self-documenting code
- Easier onboarding for new developers
Common JavaScript Pain Points We Solve
Runtime Errors
"Cannot read property 'x' of undefined" and similar errors that only appear in production.
API Integration Bugs
Backend API changes break frontend without warning, causing production incidents.
Refactoring Fear
Developers avoid refactoring because they can't be sure what will break.
Our TypeScript Migration Services
Incremental Migration
- • Codebase analysis & migration plan
- • File-by-file conversion strategy
- • TypeScript configuration setup
- • Gradual strictness increase
- • Zero downtime migration
- • Rollback-safe approach
Type Definition Creation
- • Custom type definitions (.d.ts)
- • Third-party library types
- • API contract types (OpenAPI)
- • Database schema types (Prisma)
- • Utility type helpers
- • Type documentation
Codebase Modernization
- • ES2022+ feature adoption
- • Async/await conversion
- • Module system upgrade (ESM)
- • React Hooks migration
- • Functional programming patterns
- • Code style standardization
Testing & Quality
- • Unit test migration (Vitest/Jest)
- • Type-safe test utilities
- • Integration test updates
- • E2E test migration (Playwright)
- • Type coverage reporting
- • CI/CD pipeline updates
Strict Mode Enablement
- • `strict: true` migration
- • Null safety enforcement
- • No implicit any elimination
- • Unused variables cleanup
- • ESLint TypeScript rules
- • Best practices enforcement
Team Training
- • TypeScript fundamentals workshop
- • Advanced types training
- • Best practices & patterns
- • Generics & utility types
- • Migration strategy training
- • Ongoing consultation
Our 4-Phase Migration Process
Assessment & Planning (Week 1-2)
Comprehensive codebase analysis, dependency audit, migration complexity assessment, risk identification, and detailed migration roadmap creation.
- • Migration strategy document
- • Risk assessment report
- • Timeline & resource plan
- • Static code analysis
- • Dependency graph mapping
- • Team interviews
- • 100% codebase analyzed
- • Migration plan approved
- • Team alignment achieved
Foundation Setup (Week 3-4)
TypeScript configuration, build pipeline updates, type definition installation, linting setup, and initial file conversions for proof of concept.
- • tsconfig.json (configured)
- • Build pipeline (updated)
- • 10-20% files converted
- • TS compiler setup
- • Type definitions install
- • CI/CD updates
- • Green CI/CD builds
- • Zero production impact
- • Team able to write TS
Incremental Migration (Week 5-10)
Systematic file conversion (leaf nodes first), type definition creation, API contract migration, test updates, and continuous integration with ongoing development.
- • 80-90% files converted
- • Type coverage reports
- • Migration progress dashboard
- • Weekly conversion sprints
- • Code reviews
- • Knowledge transfer sessions
- • >80% type coverage
- • All tests passing
- • No production incidents
Strict Mode & Optimization (Week 11-12)
Enable strict TypeScript mode, eliminate all 'any' types, add advanced type guards, optimize build performance, and finalize documentation.
- • 100% strict mode enabled
- • Complete documentation
- • Type library (shared types)
- • Strict mode enablement
- • Performance optimization
- • Best practices training
- • Zero 'any' types
- • 95%+ type coverage
- • Team fully trained
Migration Success Stories
Nordic E-Commerce Platform
850,000 LOC JavaScript → TypeScript
Large React/Node.js monorepo with frequent production bugs from type mismatches and API integration errors. 40+ developers struggling with codebase complexity.
Swedish Government Portal
320,000 LOC legacy JavaScript codebase
10-year-old JavaScript application with poor documentation and no type safety. High maintenance cost and difficulty onboarding new developers.
Migration Packages
Small Project
< 100,000 lines of code
- Codebase analysis & migration plan
- TypeScript setup & configuration
- Full codebase conversion
- Type definitions for dependencies
- Build pipeline updates
- Team training (4 hours)
- 6-8 weeks delivery
- 30 days support
Medium Project
100K - 500K lines of code
- Everything in Small, plus:
- Strict mode enablement
- API contract types (OpenAPI/GraphQL)
- Test suite migration & updates
- ESLint TypeScript rules
- Shared type library creation
- Advanced team training (2 days)
- 12-16 weeks delivery
- 90 days support
Enterprise
> 500K lines of code
- Everything in Medium, plus:
- Multi-repo/monorepo support
- Architecture modernization
- Performance optimization
- Custom tooling & automation
- Dedicated migration team
- Comprehensive training program
- Custom timeline
- 12 months support included
Ready to Modernize Your JavaScript Codebase?
Get a free TypeScript migration assessment. We'll analyze your codebase and provide a detailed migration plan with timeline and cost estimates.
Contact us: typescript@technspire.com | Phone: +46 722 52 52 53