CrackingWalnuts
Today's Lineup
Pattern Pick
Backtracking (Subsets/Permutations)
DSA TemplateIntermediate
ExploreDesign Blueprint
Coffee Shop Ordering
Low Level DesignStarter
ExploreScale Study
Design a Job Scheduler
System DesignHard
Deep divePacket Probe
Network Observability
Networking & ProtocolsAdvanced
ExploreStaff+ Prep
System Design at Principal Level
Staff+ InterviewExpert
ExploreKernel Dive
VXLAN & Overlay Networking
Linux InternalsAdvanced
Deep dive
Explore
DSA Templates
35Algorithm 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
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)
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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
DirectorManaging Up as a Tech Leader
“Translate technical complexity into business impact. Executives care about revenue, risk, and velocity, not architecture”
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”
530+Articles
27Interactive Tools
16Categories
6Learning Stages
Learning Path
Discover Today
Grafana Tempo
S3-native distributed tracing with no index to maintain and TraceQL for structural queries
DPDK (Data Plane Development Kit)
Complete kernel bypass. The NIC talks directly to the application through userspace memory. No syscalls, no interrupts, no socket buffers.
Merkle Trees & Anti-Entropy Repair
Two replicas can find their differences in O(log N) hash comparisons instead of comparing every record. Compare root hashes, recurse into the subtree that differs, and narrow down to exactly the divergent blocks