Systems Round Topics

Role: Production Engineer

Frequency: Reported

One 2025 final-round report covered:

• end-to-end web request flow, including browser and OS caches, recursive DNS, root/TLD/authoritative resolution, TCP, TLS, and HTTP;
• DNS record placement and UDP versus TCP behavior;
• TCP reliability versus TLS confidentiality and integrity;
• certificate validation, chain of trust, and cipher/key negotiation;
• HTTP methods, paths, headers, and bodies;
• processes, threads, virtual address spaces, page tables, and context-switch costs;
• system calls, sockets, connect, and accept;
• RAM, disk, swap, the OOM killer, mmap versus heap allocation, and runnable versus swapped processes;
• production debugging with ping, dig, traceroute, tcpdump, uptime, vmstat, htop, strace, logs, and saturation checks; and
• vertical and horizontal scaling, load balancers, CDNs, and geolocation-aware DNS.

The report did not preserve the exact wording or order of the questions.