CrackingWalnuts
Today's Lineup
Pattern Pick
Greedy (Intervals & Scheduling)
DSA TemplateIntermediate
ExploreDesign Blueprint
Elevator System
Low Level DesignIntermediate
ExploreScale Study
Design an Ad Exchange / RTB Platform
System DesignHard
Deep divePacket Probe
Routing & BGP Basics
Networking & ProtocolsAdvanced
ExploreStaff+ Prep
Cross-Team Project Leadership
Staff+ InterviewAdvanced
ExploreKernel Dive
Perf Events & Performance Counters
Linux InternalsAdvanced
Deep dive
Explore
DSA Templates
35Algorithm patterns & code templates
System Design
39End-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
Distributed Systems
38Consensus, replication & more
Linux Internals
84Kernel, networking & system calls
Cheat Sheets
24Quick reference cards for interviews
Recent Posts
System Design: LeetCode (Code Sandbox, Container Isolation, Real-Time Contests)
System Design
Apr 12, 2026 · 68 min
System Design: URL Shortener (10B Short URLs, 100K Redirects/sec)
System Design
Apr 11, 2026 · 42 min
System Design: Ad Click Aggregator (10B Clicks/day, Lambda Architecture, Fraud Detection)
System DesignData Engineering
Apr 10, 2026 · 70 min
Leadership
ManagerSecurity Culture Building
“Shift-left security works only when security tooling integrates into existing developer workflows, not alongside them”
Org Design
StartupScaling 10 to 50 Engineers
“This is the shift from 'everyone knows everything' to 'we need some structure.' It's the first real organizational growing pain”
530+Articles
27Interactive Tools
16Categories
6Learning Stages
Learning Path
Discover Today
Kafka Streams
A stream processing library that ships inside your JVM app, not a cluster you babysit
Secrets Management
Centralized secret storage with encryption at rest and fine-grained access control
Two-Phase Commit (2PC)
2PC solves the atomic commit problem: either all participants in a distributed transaction commit, or all abort. There is no state where participant A committed and participant B aborted. This is the guarantee that makes distributed transactions possible