Recent
Grid DP
·2 mins
Algorithm
Dynamic-Programming
Grid-Dp
Counting, cost optimization, reverse resource DP, and local geometry
Knapsack DP
·2 mins
Algorithm
Dynamic-Programming
Knapsack
Subset-Sum
0/1, unbounded, reachability, counting, and optimization states
Shortest Path
·2 mins
Algorithm
Graph
Shortest-Path
Dijkstra
Bellman-Ford
Dijkstra, minimax paths, and Bellman-Ford with edge limits
String DP
·2 mins
Algorithm
Dynamic-Programming
String
Lcs
Palindrome
Prefix tables, edit operations, subsequences, and interval palindrome DP
Topological Sort
·2 mins
Algorithm
Graph
Topological-Sort
Kahn
Ordering, cycle detection, dependency unlocking, and graph propagation
Redis Cache-Aside
·15 mins
Distributed Systems
Distributed-Systems
Redis
Cache-Aside
Caching
Consistency
Cache-aside, invalidation, stale reads, hot keys, and Redis outage fallback
Sharding, Hot Shards, And Cross-Shard Pain
·15 mins
Database
Database
Database-Scaling
Sharding
Hot-Shard
Multi-Tenant
Shard-key choice as workload design, not just picking a column
Replication Lag And Replica Routing
·14 mins
Database
Database
Database-Scaling
Replication
Read-Replica
Consistency
Database replication as a freshness and routing problem, not just read scaling
Transactions, Isolation, And MVCC
·17 mins
Database
Database
Transactions
Isolation
Mvcc
Locking
Oracle
A practical backend view of ACID, anomalies, MVCC, locks, and retry behavior
Composite Index And Query Triage
·13 mins
Database
Database
Composite-Index
Query-Plan
Oracle
Sargability
Query-Optimization
Reason about composite indexes through predicates, ordering, projection, plan shape, and write cost
B+Tree And Index Internals
·14 mins
Database
Database
Index
Btree
Query-Optimization
Storage-Engine
Query-Plan
Index reasoning through page reads, access paths, selectivity, row fetches, and write tax
API Design Under Failure
·10 mins
Backend
Api-Design
Idempotency
Grpc
Pagination
Retries
Observability
Retry-safe backend APIs, idempotency keys, pagination, and recoverable errors