# Systems Foundations

> Operating systems, networks, concurrency, hardware, runtimes, performance, security, and isolation.

Canonical: https://learn.significanthobbies.com/curriculum/tracks/systems-foundations

Operating systems, networks, concurrency, hardware, runtimes, performance, security, and isolation.

This track contains 8 connected concepts. Mastery means explaining each
mechanism, predicting its failure modes, and supporting decisions with code,
measurements, or a reviewable design artifact.

## Roadmaps

- [12-Week Systems Foundations](https://learn.significanthobbies.com/curriculum/roadmaps/systems-foundations-12w) — Build a mechanism-first model from hardware and kernels through runtimes, networks, performance, and isolation.
- [Trace a Tensor](https://learn.significanthobbies.com/curriculum/roadmaps/trace-a-tensor) — Follow one model workload from representation and gradients to memory, kernels, scheduling, and serving economics.

## Concepts

- [Concurrency Design](https://learn.significanthobbies.com/curriculum/concepts/concurrency-design) (advanced) — Thread-safety, locks, producer-consumer.
- [Operating System Mechanics](https://learn.significanthobbies.com/curriculum/concepts/operating-system-mechanics) (core) — Processes, threads, virtual memory, scheduling, filesystems, syscalls, and kernel boundaries.
- [Network Protocol Engineering](https://learn.significanthobbies.com/curriculum/concepts/network-protocol-engineering) (core) — Packet flow across Ethernet, IP, TCP/QUIC, TLS, DNS, HTTP, load balancers, and application protocols.
- [Compute, Memory & Storage Hierarchy](https://learn.significanthobbies.com/curriculum/concepts/compute-memory-storage-hierarchy) (core) — CPU caches, NUMA, DRAM, GPU memory, NVMe, object storage, and the movement costs between them.
- [Runtime & Performance Engineering](https://learn.significanthobbies.com/curriculum/concepts/runtime-performance-engineering) (core) — Profiling, allocation, JIT/AOT execution, garbage collection, scheduling, contention, and tail latency.
- [Security & Isolation Boundaries](https://learn.significanthobbies.com/curriculum/concepts/security-isolation-boundaries) (core) — Threat models, least privilege, capabilities, process and VM isolation, side channels, and secure defaults.
- [Data Representation](https://learn.significanthobbies.com/curriculum/concepts/data-representation) (core) — Binary and hexadecimal, two's complement, IEEE-754 floating point, Unicode, byte order, and serialized bytes.
- [Program Memory Model](https://learn.significanthobbies.com/curriculum/concepts/program-memory-model) (core) — Pointers, stack frames, heap allocation, object lifetime, executable loading, and the transition from a program on disk to a running process.