Resources

Changelog

Subroute grows one topic at a time — each shipped end-to-end with written explanations, live prototypes, and quizzes before it lands here. Newest first.

  1. Leader Election

    Latest5 concepts

    How a cluster picks one node to be in charge — and how it picks again when that node falls over. Five algorithms, from the textbook ID-based shouting matches to the lease-and-watcher schemes real coordination services ship.

    Open the track →
  2. Consensus

    7 concepts

    How a cluster agrees on a single answer when nodes die, packets drop, and some machines may even lie. Seven algorithms, from the two-phase commit that everyone learns first to the Byzantine-fault-tolerant PBFT.

    Open the track →
  3. Circuit Breaker

    6 concepts

    When a downstream service is failing, stop hammering it — fail fast instead. Six variants, from the state machine itself to the trip-condition tweaks that production resilience libraries actually ship.

    Open the track →
  4. Consistent Hashing

    5 concepts

    Map keys to servers so that adding or removing a server moves as few keys as possible. Five methods, from the classic hash ring to the table-based hashing inside modern network load balancers.

    Open the track →
  5. Load Balancing

    9 concepts

    Run more than one server and something has to decide which one handles each request. Nine algorithms, from a blind counter to capacity-and-load-aware routing — built up one signal at a time.

    Open the track →
  6. Rate Limiting

    5 concepts

    Control request throughput so a noisy client cannot starve everyone else. Compare the five canonical algorithms side-by-side.

    Open the track →
  7. Cache Eviction

    10 concepts

    When the cache fills up, something has to go — and which one you pick decides your hit rate. Ten classic policies, side-by-side.

    Open the track →
  8. Cache Write Policies

    3 concepts

    Three ways to handle a write when you have a cache in front of the store. Each policy is a different bet about durability, throughput, and how stale your data is allowed to get.

    Open the track →
  9. Page Replacement

    8 concepts

    When memory is full and a new page must come in, which page do you throw out? Eight algorithms, from the simple FIFO baseline through the unbeatable Optimal to the LRU approximations real operating systems actually ship.

    Open the track →
  10. Garbage Collection

    8 concepts

    How a runtime reclaims memory you stopped using — without you ever calling free(). Eight algorithms, from the counter on every object to the collectors that run alongside your program.

    Open the track →
  11. Memory Allocation

    6 concepts

    Before garbage collection ever runs, something has to hand out the memory. Six allocators — four ways to pick a hole, plus the two structured schemes real kernels actually ship.

    Open the track →
  12. Bloom & Cuckoo Filters

    3 concepts

    Three probabilistic set-membership structures that answer 'have I seen this before?' in a few bytes per item. From the classic bit-array Bloom filter to the counting variant that can delete, to the cuckoo filter that does it all with a smaller memory footprint.

    Open the track →
  13. Graph Algorithms

    10 concepts

    How computers reason about networks of things — roads, friends, packets, dependencies. Ten algorithms, from the two traversals every other algorithm is built on, to weighted shortest paths, minimum spanning trees, and the heuristic search behind every modern pathfinder.

    Open the track →
  14. Graph Theory

    8 concepts

    Before the algorithms, the shapes. Eight kinds of graph — directed and undirected, weighted and not, complete, bipartite, cyclic, and the all-important DAG — and how each property decides what you're allowed to do with the graph.

    Open the track →
  15. Trees

    9 concepts

    The branching data structure under databases, filesystems, autocompletes, and priority queues. Nine trees, from the plain binary search tree through the self-balancing workhorses to the disk-friendly B-trees and the range-query structures competitive programmers swear by.

    Open the track →
  16. Sorting

    10 concepts

    Order a list — ten ways. From the textbook swap-adjacent sorts you write in a single loop, to the divide-and-conquer giants, to the non-comparison tricks that beat O(n log n), to the hybrid your language's sort() actually uses.

    Open the track →

Where things are headed next lives on the Roadmap.