# Distributed Systems

> Coordination, replication, partitioning, event systems, caching, durable workflows, consistency, and recovery.

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

Coordination, replication, partitioning, event systems, caching, durable workflows, consistency, and recovery.

This track contains 11 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 Distributed Systems](https://learn.significanthobbies.com/curriculum/roadmaps/distributed-systems-12w) — Reason about coordination, data placement, logs, durable workflows, consistency, and recovery under partial failure.

## Concepts

- [Caching](https://learn.significanthobbies.com/curriculum/concepts/caching) (core) — Cache-aside, write-through, eviction policies.
- [Message Queues](https://learn.significanthobbies.com/curriculum/concepts/message-queues) (core) — Kafka, SQS, exactly-once vs at-least-once.
- [Sharding](https://learn.significanthobbies.com/curriculum/concepts/sharding) (advanced) — Range/hash/geo partitioning.
- [Replication](https://learn.significanthobbies.com/curriculum/concepts/replication) (advanced) — Leader-follower, multi-leader, quorum.
- [CAP & Consistency Models](https://learn.significanthobbies.com/curriculum/concepts/cap-theorem) (advanced) — Strong/eventual/causal, PACELC.
- [Consensus](https://learn.significanthobbies.com/curriculum/concepts/consensus) (advanced) — Raft, Paxos, leader election.
- [Distributed Infra](https://learn.significanthobbies.com/curriculum/concepts/distributed-infra) (advanced) — Service discovery, orchestration.
- [Real-time Systems](https://learn.significanthobbies.com/curriculum/concepts/messaging-realtime) (core) — WebSockets, server-sent events, presence, synchronization, ordering, reconnects, optimistic UI, and conflict handling.
- [Event Streaming & Kafka](https://learn.significanthobbies.com/curriculum/concepts/event-streaming-kafka) (core) — Partitioned logs, producers, consumer groups, offsets, ordering, delivery semantics, backpressure, and stream processing.
- [Distributed Workflows & Temporal](https://learn.significanthobbies.com/curriculum/concepts/distributed-workflows-temporal) (core) — Durable execution, event histories, deterministic replay, activities, retries, timers, and long-running workflows.
- [Distributed Failure Recovery](https://learn.significanthobbies.com/curriculum/concepts/distributed-failure-recovery) (core) — Partial failure, timeouts, retries, deduplication, fencing, repair, anti-entropy, and disaster recovery.