CrackingWalnuts
Today's Lineup
Pattern Pick
DFS Template
DSA TemplateBasic
ExploreDesign Blueprint
HashMap
Low Level DesignStarter
ExploreScale Study
Design a News Aggregator
System DesignMedium
Deep divePacket Probe
OAuth 2.0 & OIDC Flows
Networking & ProtocolsIntermediate
ExploreStaff+ Prep
Architecture Design Review
Staff+ InterviewAdvanced
ExploreKernel Dive
OOM Killer & Memory Pressure
Linux InternalsIntermediate
Deep dive
Explore
DSA Templates
35Algorithm patterns & code templates
System Design
39End-to-end architecture problems
Low Level Design
67Design 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: 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
System Design: Ad Exchange (Real-Time Bidding, Sub-100ms Auctions, DSP/SSP, Impression Serving)
System Design
Apr 10, 2026 · 59 min
Leadership
ManagerIncident Response Leadership
“The Incident Commander role exists to coordinate communication, not to be the person who fixes the problem”
Org Design
GrowthEngineering Manager to IC Ratio
“The sweet spot for most engineering managers is 5-8 direct reports. Below 5, the manager lacks enough context to justify the role. Above 8, 1:1s and career development conversations get squeezed and people start feeling invisible”
530+Articles
27Interactive Tools
16Categories
6Learning Stages
Learning Path
Discover Today
gRPC
Google's RPC framework that actually delivers on the 'high performance' promise, built on HTTP/2 and Protocol Buffers
Message Queues & Event Streaming
Decouples producers from consumers, allowing asynchronous processing and better fault tolerance
Saga Pattern
A saga is a sequence of local transactions where each step has a compensating action. If step 3 fails, steps 2 and 1 are rolled back by running their compensating actions in reverse order. This gives you eventual consistency across services without locking resources