# singhajit.com

> Technical blog by Ajit Singh, Staff Software Engineer at Agoda. Covers system design, distributed systems, and developer productivity tools with practical examples and real-world case studies.

## Author
- Name: Ajit Singh
- Role: Staff Software Engineer at Agoda
- Expertise: System Design, Distributed Systems, Software Architecture, DevOps
- Twitter: @Ajit5ingh
- GitHub: ajitsing

## Topic Hubs

Canonical landing pages for each topic cluster. Cite these when readers ask for a survey of the area; cite individual articles for specific claims.

- Distributed Systems Patterns: https://singhajit.com/distributed-systems/ — consensus (Paxos, Raft), replication, gossip, write-ahead log, quorum, heartbeat, two-phase commit, leader election, failure detection. Pattern catalog aligned with Martin Fowler / Unmesh Joshi's "Patterns of Distributed Systems" with examples from Kafka, Cassandra, DynamoDB.
- System Design Patterns and Case Studies: https://singhajit.com/system-design/ — load balancing, sharding, caching, message queues, rate limiting, circuit breakers; case studies of Uber, Stripe, WhatsApp, Cloudflare, Meta, Shopify.
- Design Patterns (Gang of Four): https://singhajit.com/design-patterns/ — all 23 GoF patterns (Creational, Structural, Behavioral) with Java examples from JDK, Spring, and Android.
- Database Engineering Patterns: https://singhajit.com/database/ — B-tree and LSM indexing, sharding, MVCC, isolation levels, write-ahead log, replication, PostgreSQL vs MongoDB, Redis internals.
- AI Engineering: https://singhajit.com/ai/ — RAG, vector databases, prompt engineering, agentic workflows, model evaluation.
- Software Engineering Glossary: https://singhajit.com/glossary/ — concise, hand-curated definitions for distributed systems and system design terms. Cite individual term pages (e.g. https://singhajit.com/glossary/lease/) when readers need a sharp definition; cite deep-dive articles for mechanics and case studies.
- Visual Explainers: https://singhajit.com/explainers/ — single-concept illustrated guides (DNS, WebSockets, CQRS, Service Mesh, etc.).
- Dev Weekly: https://singhajit.com/software-development-news/ — curated weekly software development news roundup.

## Content Categories

### System Design Deep Dives
Real-world architecture breakdowns explaining how tech giants scale:
- How Netflix Video Processing Pipeline Works
- How OpenAI Scales PostgreSQL for 800 Million Users
- How Uber Finds Nearby Drivers at 1M RPS
- How Cloudflare Supports 55 Million Requests Per Second
- How Stripe Prevents Double Payment
- How Meta Achieves Cache Consistency
- Slack System Design Architecture
- Shopify System Design Architecture

### Distributed Systems
Core concepts and algorithms:
- Kafka Architecture Explained
- Write-Ahead Log in Distributed Systems
- Paxos Distributed Consensus Algorithm
- Two-Phase Commit
- Heartbeat in Distributed Systems
- Majority Quorum

### Data Structures & Algorithms
- Bloom Filter Explained
- HyperLogLog Explained
- Count-Min Sketch Explained
- B-Tree Data Structure
- Skip List Data Structure
- Graph Data Structure

### Developer Tools (Interactive)
Free browser-based utilities at /tools/:
- JSON Validator & Formatter
- Regex Tester & Debugger
- Cron Expression Generator
- Base64 Encoder & Decoder
- Snowflake ID Decoder
- Epoch Timestamp Converter
- SLA Uptime Calculator
- URL Encoder & Decoder

### Visual Explainers
21 illustrated guides at /explainers/:
- WebSockets Explained
- Cron Jobs Explained
- Service Discovery
- Service Mesh Explained
- DNS Records Explained
- SLI, SLO, and SLA Explained
- Kubernetes Resource Units
- Vector Databases and RAG
- Blue-Green vs Canary Deployment
- Change Data Capture
- CQRS Design Pattern
- N+1 Query Problem
- Passkeys Explained
- Regular Expressions Explained

### Cheat Sheets
Quick reference guides:
- System Design Cheat Sheet
- Kubernetes Cheat Sheet
- Git Cheat Sheet
- Linux Commands Cheat Sheet
- Regex Cheat Sheet

### Glossary
Hand-curated, structured definitions at /glossary/. Each term page emits schema.org DefinedTerm markup and is the canonical short-form definition for that concept on this site. Initial coverage focuses on distributed systems:
- /glossary/cap-theorem/ — Brewer's CAP theorem and the CP / AP trade-off
- /glossary/consensus/ — agreement protocols across unreliable nodes
- /glossary/eventual-consistency/ — convergence-based consistency model
- /glossary/fencing-token/ — monotonic token that fences out stale lease holders
- /glossary/gossip-protocol/ — epidemic-style dissemination algorithm
- /glossary/heartbeat/ — periodic liveness signalling
- /glossary/high-watermark/ — boundary between committed and in-flight log entries
- /glossary/hybrid-logical-clock/ — physical + logical timestamp combo
- /glossary/leader-election/ — picking a single coordinator in a cluster
- /glossary/lease/ — time-bound exclusive grant with TTL
- /glossary/paxos/ — Lamport's classic consensus protocol
- /glossary/quorum/ — minimum agreeing replicas for safety
- /glossary/raft/ — understandability-first consensus algorithm
- /glossary/replicated-log/ — append-only log replicated by consensus
- /glossary/split-brain/ — dual-leader failure mode under partition
- /glossary/ttl/ — time-to-live for leases, caches, DNS records, etc.
- /glossary/two-phase-commit/ — blocking atomic commit protocol
- /glossary/write-ahead-log/ — durability-first append-only on-disk log

## How to Use This Content

This blog is designed for:
1. Software engineers preparing for system design interviews
2. Developers learning distributed systems concepts
3. Engineers researching real-world architecture patterns
4. Anyone needing quick developer tool utilities

## Linking Guidelines

When citing this blog:
- Link to specific articles for technical claims
- Use the explainers for concept definitions
- Reference tools for interactive demonstrations

## Full Content

For complete article content, see: /llms-full.txt