Interview questions
Frequently asked questions with concise model answers. Try answering aloud before expanding.
Explain middleware. Easy
Middleware are hooks that process every request/response globally — e.g. sessions, authentication, CSRF, security headers. They run in order on the request and in reverse on the response.
What makes an API RESTful? Easy
Resources identified by URLs, standard HTTP methods, stateless requests, meaningful status codes, and representations (usually JSON). Good APIs also version, paginate and document.
What is a p-value? Medium
The probability of observing results at least as extreme as the data, assuming the null hypothesis is true. A small p-value suggests the data are unlikely under H₀ — it is not the probability that H₀ is true.
VLOOKUP vs XLOOKUP? Easy
XLOOKUP can search in any direction, defaults to exact match, returns a custom value when not found and doesn't break when columns are inserted. VLOOKUP only looks right and needs a column index.