Operating Systems & Systems Programming Topics
Covers operating system fundamentals and systems programming topics, including process management, memory management, file system interfaces, inter-process communication, low-level kernel interactions, and system call interfaces (e.g., fork, exec, opendir, stat) across Unix/Linux and other OS environments.
Linux System Administration & Networking
Operating and troubleshooting Linux hosts: users and groups, packages, cron, logging, and the /proc and /sys interfaces, together with host-level networking such as interfaces, routing, DNS resolution, ports, and firewall rules. Covers diagnosing connectivity and configuration issues with standard tooling on a running Linux system.
Linux Command Line & Shell
Working effectively at the Linux/Unix shell: core commands, file and text manipulation, pipes and redirection, process control, permissions and ownership, and shell scripting fundamentals. Covers navigating the filesystem, chaining tools, and the everyday command-line workflow expected of anyone operating Linux systems.
System Calls & the Kernel Interface
The boundary between user space and the kernel: how programs request privileged services through system calls, the user/kernel mode transition, and the semantics of core POSIX calls such as fork, exec, wait, open, read, write, and stat. Covers syscall numbers, arguments, return values and errno, and how libc wrappers relate to the underlying trap. This is the foundational interface for all systems programming on Unix/Linux.
State Machines & Protocol Implementation
Modeling behavior and communication with explicit state: finite state machines, event-driven transitions, and implementing wire or hardware protocols with framing, timeouts, and error handling. Covers structuring long-lived logic as a state machine to keep firmware and systems code correct and testable.
Systems Performance Analysis & Tuning
Finding and fixing performance problems at the OS and low level: profiling CPU, memory, I/O, and lock contention, reading utilization and saturation signals, and using tools like perf, strace, and tracepoints. Covers cache behavior, false sharing, syscall overhead, and the methodology of isolating a bottleneck before optimizing.
Concurrency, Synchronization & Deadlock
Correctness of shared-state coordination between concurrent threads and tasks. Covers mutexes (futex-based and spin-then-sleep), semaphores, condition variables, spinlocks, reader-writer locks, and the producer-consumer pattern; atomic operations, compare-and-swap, lock-free and wait-free structures with the ABA problem and safe memory reclamation; memory ordering, barriers and acquire/release semantics; race conditions, data races, critical sections, time-of-check to time-of-use gaps and read-modify-write hazards; deadlock (the Coffman conditions, lock ordering, prevention and detection), livelock and starvation; priority inversion as a locking hazard and the priority-inheritance fix; designing thread-safe structures such as bounded queues, caches, rate limiters, event buses and work-stealing schedulers, with coarse versus fine-grained and per-key locking; alternatives to locking such as thread confinement, message passing, actors and transactional memory; and diagnosing and testing concurrency bugs (heisenbugs, race detectors, stress and replay, reviewing concurrent code). Excludes a specific language's threading API and memory model, concurrency for throughput and pool tuning, distributed locks and consensus, database isolation levels, RTOS ceiling protocols and schedulability, and interrupt masking between ISRs and main code.