Changelog

A record of every significant update to the platform.

v2.012 April 2026
28 tracks, 343+ tasks across 8 categoriesFull subtrack grouping for all tracks7 programming languages supported

New Tracks (14 tracks added)

  • The Timekeeper — physical clocks, Lamport clocks, vector clocks, HLC (20 tasks)
  • The Networker — TCP from scratch, message framing, gRPC/Protobuf (15 tasks)
  • The Logger — WAL, LSM tree, B-tree on disk, distributed log (20 tasks)
  • The Filesystem — GFS-style distributed file storage (10 tasks)
  • The Watcher — ZooKeeper-style coordination, ZAB protocol, etcd API (15 tasks)
  • The Searcher — document store, full-text search, distributed sharding (10 tasks)
  • The Scheduler — centralized scheduling, MLFQ, DAG scheduling, work stealing (10 tasks)
  • The Tracer — distributed tracing, span lifecycle, metrics, alerting, dashboards (10 tasks)
  • The Securitor — JWT, OAuth 2.0, RBAC, AES-GCM, RSA, E2EE (10 tasks)
  • The Migrator — schema migrations, zero-downtime, API versioning, protocol evolution (10 tasks)
  • The Orchestrator — job scheduling, DAG workflows, service mesh, circuit breaking (10 tasks)
  • The Reactor — event sourcing, CQRS, sagas, projections (10 tasks)
  • The MapReducer — MapReduce fundamentals, stream processing, watermarks, exactly-once (10 tasks)
  • The Queues — exactly-once delivery, idempotent consumers, outbox pattern (5 tasks)

Expanded Existing Tracks (subtracks added)

  • The Messenger — added RPC request-response and Protocol Beneath subtracks (15 tasks total)
  • The Identifier — added Snowflake IDs, logical clocks, HLC subtracks (19 tasks total)
  • The Gossiper — added gossip protocol, topology-aware, epidemic CRDT subtracks (19 tasks total)
  • The Counter — added G-counter/PN-counter and more CRDTs subtracks (15 tasks total)
  • The Consensus — added Paxos, Byzantine fault tolerance subtracks (20 tasks total)
  • The Store — added read optimization and transactional Raft subtracks (15 tasks total)
  • The Sharder — added consistent hashing and cross-shard queries subtracks (15 tasks total)
  • The Coordinator — added three-phase commit and saga pattern subtracks (15 tasks total)
  • The Proxies — added API gateway subtrack (10 tasks total)
  • Load Balancers — added Layer 7 LB and advanced balancing subtracks (15 tasks total)

Language Support

  • Go — starter code for all 343 tasks
  • Rust — starter code for all 343 tasks
  • C++ — starter code for all 343 tasks
  • JavaScript (Node.js) — starter code for all 343 tasks
  • TypeScript — starter code for all 343 tasks
  • C — starter code for all 343 tasks
  • Java — starter code for all 343 tasks
  • File label in editor now shows correct extension per language (main.py, main.go, main.ts, etc.)
v1.0January 2026
15 tracks, 75 tasks across 4 categoriesPython and Go supportMaelstrom-compatible message protocol

Initial Tracks

  • The Messenger — JSON parsing, init handler, echo service, envelope validation, async handler
  • The Identifier — unique ID generation with node ID, timestamp, random salt
  • The Gossiper — broadcast, tree topology, random gossip, batching, partition healing
  • The Counter — lost update problem, KV integration, CAS, G-counter
  • The Elector — Raft leader election: node states, heartbeat, randomized timeouts
  • The Consensus — Raft log replication: log matching, commitment, state machine
  • The Store — linearizable KV store on Raft: routing, read consistency, snapshots
  • The Sharder — range sharding, consistent hashing, config change, data migration
  • The Coordinator — 2PC, coordinator failure, 3PC, sagas, transactional KV
  • Advanced — MapReduce, DHT, PBFT, stream processing, CRDTs
  • Caches — request cache, global cache, distributed cache, LRU/TTL, invalidation
  • Proxies — relay proxy, request dedup, collapsed forwarding, reverse proxy
  • Indexes — hash index, B-tree, LSM tree, secondary indexes, distributed index
  • Load Balancers — round robin, least connections, health checks, consistent hashing
  • Queues — basic queue, consumer groups, at-least-once, exactly-once, DLQ