Two years ago, we made the decision to adopt TypeScript for all new projects at Xelent Solutions. Today, we cannot imagine going back. Here is why TypeScript has become our language of choice for web development.
The Problem with Plain JavaScript
JavaScript's flexibility is both its greatest strength and its most significant weakness. Dynamic typing makes it easy to get started but creates challenges as codebases grow:
- Runtime errors that could have been caught at compile time
- Refactoring anxiety — changing one function might break unknown consumers
- Poor discoverability — without types, understanding API contracts requires reading implementation code
- Onboarding friction — new team members struggle to understand complex codebases
What TypeScript Brings
TypeScript adds optional static typing to JavaScript. It compiles to plain JavaScript and runs anywhere JavaScript runs. The key benefits we have experienced:
Catch Bugs Before Runtime
TypeScript's type checker catches entire categories of bugs at compile time. Null reference errors, incorrect function arguments, missing properties — these common JavaScript pitfalls are flagged before code ever runs.
Superior IDE Support
With type information, editors like VS Code provide accurate autocomplete, inline documentation, and intelligent refactoring tools. This dramatically improves developer productivity.
Self-Documenting Code
Types serve as living documentation. Function signatures clearly communicate what parameters are expected and what will be returned. Interfaces define the shape of data structures.
Safer Refactoring
When you rename a property or change a function signature, TypeScript immediately flags every location that needs to be updated. Large-scale refactoring becomes a routine task rather than a risky endeavor.
Our Migration Strategy
We did not rewrite everything overnight. Instead, we followed a gradual migration approach:
- New projects start in TypeScript — No exceptions
- Rename
.jsto.tsincrementally — TypeScript is valid JavaScript, so files can be migrated one at a time - Enable strict mode gradually — Start with basic type checking and increase strictness over time
- Write types for external dependencies — Use DefinitelyTyped or write custom type declarations
The Results
After one year of TypeScript adoption, we observed:
- 40% fewer production bugs related to type errors
- 30% faster onboarding for new team members
- Significantly faster refactoring with full confidence in the changes
- Better code reviews — types make intent clearer and discussions more focused
Conclusion
TypeScript requires a small upfront investment in learning and setup, but the return is substantial. For any team building non-trivial JavaScript applications, TypeScript is not just an improvement — it is a necessity.
