This was for an internship.

1 HR round, 1 coding round, 2 design/conceptual knowledge rounds.

I won't tell the exact questions. But here are some tips,

The HR round had some technical questions (short, pop-quiz type) on Linux and networks.

The coding round is easy. 5 questions. One had to be done by recursion, others were on text processing. It was on coderpad.io. You can use any language you want to code.

2 conceptual/design interviews. Many questions on systems knowledge (networks, OS, Linux, SSL, etc). To prepare: read the Networks: Top Down Approach book. For Linux, do Unix and Linux Sys Admin's Handbook. For system design, Google "System Design Primer". It's a GitHub link.

That was it. No on-site (for interns).

Describe what happens when you do "curl."