JavaScript is one of the most popular languages in the world, and for good reason. But as projects and teams grow, its shortcomings start to become obvious. TypeScript is a superset of JavaScript that adds strong typing and other useful features that let developers work faster and more independently but don't affect your codebase or APIs. Here are a few ways TypeScript helps your company build at scale.

1. Don't stop working while you upgrade

Maintaining momentum is critical to scaling, and any time spent on relearning or implementing a new system is time lost from development. TypeScript helps with this because it doesn't necessitate a pause while your existing code is revised and updated. At the end of the day, TypeScript compiles down to ordinary JavaScript, which means all of your code and its documentation will remain recognizable and usable from start to finish.

This de-risks and simplifies the process of migrating, as you can start with a small team or project to pilot TypeScript without affecting the entire codebase, and begin porting over existing code as you establish best practices and standards. Or just bring everyone on board and implement features as you see fit.

2. Improved documentation and smooth coding

As projects grow, type safety increasingly becomes an issue. With multiple teams and products, it's reasonable to worry whether making a change might have far-reaching consequences. Developers have to go down a rabbit hole of double-checking the inputs, outputs, and dependencies of functions and arguments.

TypeScript makes this an intuitive in-line check so a developer doesn't even have to change tabs in their IDE, let alone look up the official documentation or send an email. If you call a function, you know right away what it returns, or if an argument is required, optional, or nullable. There are built-in safety rails so a developer is less likely to introduce new bugs they might not even know about.

Best of all, this built-in documentation and code coverage happens naturally as your team builds types, and the information is available automatically across your company, streamlining the testing process and letting developers work confidently and quickly.

3. Compiling for simplicity and safety

Catching and understanding bugs and errors are crucial as scopes grow and these inevitable speed bumps multiply. Fortunately, TypeScript code compiles down to JavaScript, which has two benefits.

First, errors are caught at the compile step rather than during runtime where they can impact users. If there are problems, they're going to be found during development and not after a big merge gets pushed live. TypeScript's error messages are also extremely detailed, which can be intimidating to novices, but ultimately makes fixes faster.

Second, your existing organizational expertise on squashing JavaScript bugs isn't wasted. Your non-TypeScript workarounds and snippets will work just like they did before, meaning less time is wasted re-implementing known solutions.

4. TypeScript's popularity means it's widely supported

Whatever platforms and packages your team is using, chances are they already support TypeScript. Even if there isn't an official type file included, the community has you covered. The rapid adoption of TypeScript for large-scale projects means virtually all popular libraries will be supported one way or the other.

As a bonus, when bringing in a new package or dependency, it will automatically include TypeScript’s benefits, such as in-line documentation of the library’s functions and variables. This speeds integration by letting developers code more quickly and effectively since they’re not constantly referring to each dependency’s documentation website.

5. Works with React and other Front-end frameworks

If a developer is working within a design system — and they probably should be — chances are they're going to be working with a component library. Using a front-end framework that has first-class TypeScript support (such as React, Vue or Angular) makes for less friction between development teams. The TypeScript team has done a tremendous job of creating types for HTML elements and the Javascript standard library, making front-end work far less confusing and error-prone.

// Who remembers that the return type of querySelectorAll is not a regular array, but a NodeList?
const images = document.querySelectorAll(‘img’)
const areAllImagesLoaded = images.every(image => image.complete)
//                                ^^^
// Property 'every' does not exist on type 'NodeListOf<HTMLImageElement>'.ts(2339)

// TypeScript warns us immediately, as a popup in our IDE that we must cast the NodeList to an Array
const areAllImagesLoaded = Array.from(images).every(image => image.complete)

If everyone in your company is working with the same standards and documentation, everyone works faster and more confidently.

6. Collaborate more effectively across teams

TypeScript enables teams to build mission-critical software confidently because it effectively provides contracts for functions and classes. Separate teams working on overlapping projects will collaborate better because they can clearly see what's expected in function calls or types for recently created variables — no comment check or Slack message required. And built-in linting highlights unexpected inputs as they're written, warning of changes and letting individuals adapt to modifications made by other teams in real-time.

7. Save time and frustration by testing as you go

Testing is an important part of any coding process, but with TypeScript, you won't have to leave it to the end and find out about a dozen problems all at once. Between improved in-line documentation, warnings of unexpected inputs, and the unlikelihood of errors getting past compilation, bits of testing are scattered throughout the workflow in TypeScript. Building in fixes as you go doesn't just save time and simplify things, it's also just more natural, like correcting a typo right away rather than running spell check at the end.

8. Let developers "leave it better than they found it"

When developers come across code that could be rewritten for better performance, legibility, or optimization purposes, they often find themselves between two competing impulses. On one hand, they know they could improve the code, but on the other, they're not sure whether doing so might break something further down the line in code they aren't aware of or in charge of. So despite wanting to tidy up code they let it be.

Fortunately, TypeScript's safety rails prevent accidental sabotage of distant code, providing a basic sanity check that frees developers to "leave it better than they found it." Such small improvements add up quickly and your project's code hygiene will improve noticeably.

What's your next step?

TypeScript clearly has a lot of benefits for coding at scale, but if you have any questions about whether or how your organization should adopt it, talk to one of our experts today — or read our next piece, in which we'll speak about how to seamlessly migrate existing codebases to TypeScript.