Clean Code: Writing Maintainable JavaScript in 2025

Why readability matters

Your code is read far more often than it's written. Clear naming and small functions make debugging and onboarding easier.

1. Name things by what they do

// ❌ Vague
const d = new Date();
const data = await fetchData();

// ✅ Clear
const publishedAt = new Date();
const userProfile = await fetchUserProfile();

2. Keep functions small and focused

One level of abstraction per function. If you need to add "and then" while describing it, split it.

// One job: validate and save
async function saveBlogPost(formData) {
  const validated = validateBlogPost(formData);
  if (!validated.ok) return validated;
  return await api.post("/api/blogs", validated.data);
}

3. Prefer constants over magic values

const MAX_TITLE_LENGTH = 120;
const DEFAULT_PAGE_SIZE = 10;

4. Use TypeScript for intent

Types document your API and catch mistakes early:

interface BlogPost {
  title: string;
  slug: string;
  published: boolean;
}

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Takeaway: Good code reads like prose. Name well, keep functions small, and let types document your design. Your future self (and your team) will thank you.