What is the command used to import external modules?

0-2 years experience

1. 1You need to use the lodash library in a small script. How would you import it?
2. 2If you forget to install a module and try to require it, what error do you see?
3. 3Write the line of code you would use to import the built‑in 'fs' module.

2-5 years experience

1. 1Your feature loads a JSON config file using require. It works locally but fails in production. What could cause the require to break?
2. 2You need to load a module only when an environment variable is set. How would you write that import?
3. 3Explain the practical differences between using require and import in a Node.js project that uses Babel.

5-8 years experience

1. 1Your service loads many plugins at startup with require and you notice high latency. What strategies can reduce module‑loading overhead?
2. 2You are refactoring a large codebase from CommonJS to ES modules. What challenges arise with the import syntax and how would you address them?
3. 3Design a wrapper that abstracts module loading so the same code works with both require and import across Node and the browser.

8+ years experience

1. 1Your organization plans to migrate all internal services to ES modules to enable tree‑shaking. What architectural considerations, tooling changes, and cross‑team coordination are required?
2. 2When introducing a new module‑loading convention across multiple microservices, how do you ensure backward compatibility and avoid breaking existing deployments?
3. 3Discuss the long‑term maintenance trade‑offs of standardizing on import versus require in a polyglot environment with legacy code.