dev atlas

Event loop, closures, prototypes, async/await, generators, TypeScript type system, generics, decorators, async patterns, concurrency models, functional & OOP programming

V8, libuv, streams, buffers, worker threads, cluster, child processes, HTTP internals, performance profiling, memory leaks, databases, SQL, NoSQL, Redis, API design, REST, GraphQL, gRPC, WebSockets

React 19, hooks, concurrent features, state management, Next.js App Router, Server Actions, browser internals, critical rendering path, Core Web Vitals, bundle optimization, Bun, Deno, edge runtimes

System design, HLD/LLD, SOLID, microservices, DevOps, Docker, Kubernetes, CI/CD, testing (Jest, E2E), security (OWASP), DSA, algorithms, interview practice, behavioral STAR stories

SQL deep dive, indexing (B-trees, covering indexes), transactions & ACID, isolation levels, PostgreSQL internals, Redis patterns, MongoDB, connection pooling, sharding, replication, schema design, CQRS, event sourcing

AWS core services (IAM, EC2, S3, RDS, Lambda, SQS/SNS, ECS), Terraform, CDK, serverless patterns, Step Functions, EventBridge, DynamoDB, CloudFront, observability, cost optimization

Python essentials, NumPy, Pandas, matplotlib/seaborn, scikit-learn, PyTorch, FastAPI, async Python, OpenAI/Anthropic/HuggingFace SDKs, structured outputs, prompt caching, tooling

LLM APIs, prompt engineering, RAG, vector DBs, LangChain, LangGraph, agentic AI, MCP, AI in production, fine-tuning, RAGAS evaluation, reasoning models, local LLMs, observability, cost optimization

OSI & TCP/IP models, IP addressing, subnetting, CIDR, TCP/UDP, DNS, HTTP/2/3, TLS handshake, routing, NAT, firewalls, VPC, security groups, load balancers, CDN, troubleshooting

All quick-reference cheatsheets in one place — JavaScript, React, Frontend, Backend, DSA patterns, System Design. Optimised for last-minute interview revision.