1
Choose your stage
New to systems? Begin with Foundations. Otherwise, choose the stage closest to what you already know.
2
Build in order
Open a system and complete its levels from basic behavior through correctness, scale, measurement, and optimization.
3
Follow your progress
A completed level updates your progress. Finish the systems in one stage before moving to the next.
What the colors mean
Foundations & Runtimes
Storage & Persistence
Traffic & Concurrency
AI Systems & LLMs
Completed: 0 systems completed
Systems Engineering
TIER 1: BEGINNER FRIENDLY • SYSTEMS FOUNDATIONS
Beginner• 2 Core Systems
Process lifecycle, POSIX system calls, non-blocking I/O and protocol framing.
fork() & execve()POSIX File DescriptorsO_NONBLOCK & epollHTTP/1.1 Framing
STAGE 1
FOUNDATIONS
Operating System Primitives
STAGE 1FOUNDATIONS
Operating System Primitives
Process lifecycle, POSIX system calls, non-blocking I/O and protocol framing.
STAGE 2
DATA STRUCTURES & MEMORY
In-Memory State & Caching
Beginner• 3 Core Systems
Hash collisions, doubly linked lists, TTL eviction, and high-frequency metrics.
Hash Table BucketsO(1) LRU EvictionRing BuffersColumnar Aggregations
STAGE 2DATA STRUCTURES & MEMORY
In-Memory State & Caching
Hash collisions, doubly linked lists, TTL eviction, and high-frequency metrics.
TIER 2: INTERMEDIATE • TRAFFIC & DURABILITY
Intermediate• 3 Core Systems
Rate limiting algorithms, weighted packet dispatch, and multi-resource bin packing.
Token Bucket & Leaky BucketSmooth Weighted RRLeast-Connection RoutingDominant Resource Fairness
STAGE 3
CONCURRENCY & NETWORKING
Traffic Control & Routing
STAGE 3CONCURRENCY & NETWORKING
Traffic Control & Routing
Rate limiting algorithms, weighted packet dispatch, and multi-resource bin packing.
STAGE 4
DURABILITY & PERSISTENCE
Storage Engines & Persistence
Intermediate• 4 Core Systems
Slotted page formats, content-addressable Merkle DAGs, and partitioned commit logs.
B+ Tree Slotted PagesMerkle Tree HashesChunk DeduplicationZero-Copy Partition Logs
STAGE 4DURABILITY & PERSISTENCE
Storage Engines & Persistence
Slotted page formats, content-addressable Merkle DAGs, and partitioned commit logs.
TIER 3: ADVANCED & EXPERT • DISTRIBUTED & AI
Advanced• 4 Core Systems
OS namespaces, Raft quorum replication, gossip failure detectors, and erasure codes.
Raft Leader ElectionLinux PID/Mount NamespacesGossip SWIM ProtocolReed-Solomon Erasure Coding
STAGE 5
DISTRIBUTED SYSTEMS
Distributed Consensus & Isolation
STAGE 5DISTRIBUTED SYSTEMS
Distributed Consensus & Isolation
OS namespaces, Raft quorum replication, gossip failure detectors, and erasure codes.
STAGE 6
AI & NEURAL RUNTIMES
AI Systems & Neural Runtimes
Advanced• 4 Core Systems
Inverted text indexes, HNSW proximity graphs, PagedAttention KV caches, and MCP protocols.
BM25 Inverted IndexHNSW Proximity GraphsPagedAttention KV CacheMCP JSON-RPC Stdio
STAGE 6AI & NEURAL RUNTIMES
AI Systems & Neural Runtimes
Inverted text indexes, HNSW proximity graphs, PagedAttention KV caches, and MCP protocols.
CAPSTONE GRADUATION
Systems Architect Mastered
Complete every system currently in the roadmap, from single-process Unix runtimes to distributed consensus and AI infrastructure.