Focused, hands-on problems for sharpening your DevOps and server-side skills. Some teach specific concepts while others mirror real-world scenarios. Every challenge includes hints, feedback, and automated solution checks.
A Job manifest at /home/laborant/batch-job.yaml is exiting with a non-zero exit status. The Job has limited retries configured. Inspect the cluster and the manifest to find the bug, fix it, and reapply.
A stubborn process is running on the system, kill it :)
Refactor a slow, single-threaded C file downloader that fetches files sequentially into a multi-threaded program using POSIX Threads (pthreads) to achieve concurrent downloads.
Write a C program that calls fork() to clone a process and execve() to execute a command, then print and retrieve the child process PID.
Compile a small C loop with -O2 -S, inspect the generated assembly, report how many add instructions gcc produced and see how much it has optimized the equasion.
Run gcc -E on a small C program and find the exact line where the preprocessor expanded a macro into a printf call.
A newly provisioned server is reachable as root with a shared seed password. Create a sudoer admin user, switch SSH to key-based access, disable password and root logins, and retire the seed credential.
A remote VM serves an app on port 80 and keeps an internal debugging port bound to 127.0.0.1. Reach the debugging port from your workstation using an SSH tunnel, without exposing it on the VM's external interface.
Write your first TCP client for a push-only telemetry server that starts sending sensor readings as soon as you connect. Likely the easiest way to get started with TCP socket programming.
A systemd-managed worker process starts cleanly, prints a few heartbeat lines, then silently vanishes - over and over again. Diagnose why the process keeps dying and stabilize the service.
