CrackingWalnuts
New
Concurrency section is live
145 topics: mental models, patterns, Go, Java, Python, real-world, performance, lock-free, debugging
Today's Lineup
Pattern Pick
Prefix Sum
DSA TemplateBasic
ExploreDesign Blueprint
Inventory Management
Low Level DesignAdvanced
ExploreScale Study
Design a URL Shortener
System DesignEasy
Deep divePacket Probe
TCP vs UDP Decision Framework
Networking & ProtocolsBeginner
ExploreStaff+ Prep
Architecture Design Review
Staff+ InterviewAdvanced
ExploreKernel Dive
mmap & Memory-Mapped Files
Linux InternalsIntermediate
Deep dive
System Design: Maps Platform (Navigation, Routing, and Map Rendering)
Design a maps platform serving 1B daily users with real-time routing, tile rendering, traffic overlays, and offline navigation.
Read article
System Design··79 min
Explore
DSA Templates
50Algorithm patterns & code templates
System Design
41End-to-end architecture problems
Low Level Design
90Design patterns & practical code
Key Technologies
59Deep dives into core tech
Infrastructure
35Production systems & operations
Networking & Protocols
51TCP, HTTP, TLS, DNS & more
Concurrency
145Threads, channels, async, locks in Java + Python + Go
Distributed Systems
38Consensus, replication & more
Linux Internals
84Kernel, networking & system calls
Cheat Sheets
24Quick reference cards for interviews
Recent Posts
System Design: GitHub (200M Repos, Git Object Storage, Sparse Trigram Code Search, Per-Job VM CI)
System Design
Apr 23, 2026 · 69 min
System Design: Online Auction (50K Bids/sec, Effectively-Once Settlement, Anti-Sniping)
System Design
Apr 17, 2026 · 83 min
System Design: Job Scheduler (10M Jobs/day, DAG Dependencies, Effectively-Once Execution)
System Design
Apr 15, 2026 · 61 min
Leadership
ManagerBuild vs Buy Framework
“Compare total cost of ownership over 3 years, including maintenance, integration, training, and opportunity cost”
Org Design
GrowthAI Adoption & Change Management
“AI adoption is a change management problem, not a technology problem. The hardest part is never the model. It's getting people to trust it and actually change how they work”
800+Articles
27Interactive Tools
18Categories
6Learning Stages
Learning Path
Discover Today
TimescaleDB
Full PostgreSQL with time series superpowers bolted in at the storage layer
Caching Strategies
Cuts database load and latency by serving hot data from in-memory stores instead of disk
ZSTD Compression (Zstandard)
ZSTD combines LZ77-style dictionary matching (find repeated byte sequences, replace with back-references) with two entropy coders: Finite State Entropy (FSE) for match lengths and offsets, and Huffman coding for literal bytes. This three-stage pipeline achieves gzip-level compression ratios at LZ4-level speeds