CrackingWalnuts
Today's Lineup
Pattern Pick
Grid BFS / Multi-source BFS
DSA TemplateIntermediate
ExploreDesign Blueprint
Event Sourcing System
Low Level DesignAdvanced
ExploreScale Study
Design Dropbox
System DesignHard
Deep divePacket Probe
Serialization & Wire Formats
Networking & ProtocolsIntermediate
ExploreStaff+ Prep
Data Architecture & Schema Evolution
Staff+ InterviewAdvanced
ExploreKernel Dive
Inter-Process Communication (Pipes & FIFOs)
Linux InternalsStarter
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: Job Scheduler (10M Jobs/day, DAG Dependencies, Effectively-Once Execution)
System Design
Apr 15, 2026 · 61 min
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
Leadership
ManagerTech Debt Negotiation
“Quantify tech debt in business terms: hours lost per sprint, how often incidents happen, or how much deployment lead time has degraded”
Org Design
GrowthScaling 50 to 200 Engineers
“This is the 'messy middle,' too big for startup informality but too small for enterprise bureaucracy. You have to find a careful balance between structure and speed”
530+Articles
27Interactive Tools
16Categories
6Learning Stages
Learning Path
Discover Today
Kafka
The distributed commit log that became the backbone of event streaming
Serverless & FaaS
Run code without managing servers. The cloud provider handles provisioning, scaling, and patching.
Vector Clocks & Version Vectors
Lamport clocks tell you 'event A happened before event B' but cannot tell you whether two events are truly concurrent. Vector clocks can. If neither vector dominates the other (one is not component-wise less than or equal), the events are concurrent, and you know there might be a conflict