Software and IT roles
Common conceptual questions for developers and IT support.
1. Explain the difference between a process and a thread.
How to answer: A process has its own memory space; threads in a process share memory. Mention why that makes threads lighter but needs care with shared data.
2. What is the difference between SQL joins: INNER and LEFT?
How to answer: INNER returns only matching rows from both tables; LEFT returns all rows from the left table plus matches, with empty values where there is no match. Draw two small tables if allowed.
3. What happens when you type a web address into a browser?
How to answer: Walk through it in order: DNS lookup, connection and HTTPS, request, server response, then the browser rendering the page. Depth beats a long list.
4. How do you debug a problem you cannot reproduce?
How to answer: Describe collecting logs and details, narrowing the conditions, forming a guess, testing it and adding a check so it is caught next time.
5. What is version control and why do teams use it?
How to answer: It records changes so people can work in parallel, review, undo and see history. Mention branches and pull requests if you have used them.
6. Tell me about a system or code you are proud of.
How to answer: Explain the problem, your design choices, the trade-offs and what you would improve. Interviewers look for your reasoning.
Use these as a guide and answer from your own real experience. Never invent examples. See our disclaimer.