Blue/Green vs Canary Deployments
Six deployment strategies (recreate, rolling, blue/green, canary, feature flags, shadow) compared. When each makes sense and the database problem common to all of them.
DevOpsKubernetes Architecture
The control plane and worker nodes. Pods, deployments, services, ingress. The reconciliation loop that makes K8s self-healing.
DevOpsDocker Fundamentals
What containers actually are. Images, layers, volumes, networking, and Docker Compose. Best practices for production Dockerfiles.
DevOpsHow CI/CD Actually Works
CI vs CD vs CD. The pipeline stages from git push to production. The build-once-promote pattern, branch strategies, feature flags, and pipeline security.
DevOpsDNS Deep Dive
The hierarchy (root, TLD, authoritative), record types, TTLs and caching, GeoDNS, and why so many internet outages start with DNS.
NetworkinggRPC vs REST
Performance, tooling, ecosystem. When to pick which, the GraphQL aside, and the hybrid approach most large companies actually use.
NetworkingWebSockets vs SSE vs Polling
Three approaches to real-time updates from server to browser. Latency, complexity, browser support, and operational concerns compared.
NetworkingTCP vs UDP
Reliability vs speed, the protocols' actual behavior, where each shines, and how QUIC blurs the line between them.
NetworkingHTTP/1 vs HTTP/2 vs HTTP/3
Head-of-line blocking, multiplexing, HPACK header compression, and QUIC. How each version solved the bottleneck of the last.
NetworkingAPI Authentication Patterns
API keys, Basic Auth, JWT bearer tokens, OAuth, HMAC signing, mTLS, sessions. The major patterns compared with when to use each.
SecurityPassword Hashing Done Right
Argon2id, bcrypt, salts, peppers, and the parameters that actually keep credentials safe. Plus passkeys as the future.
SecurityThe TLS/SSL Handshake
What happens when you visit an HTTPS site. The TLS 1.2 vs TLS 1.3 handshakes, certificates, the trust chain, cipher suites, and why symmetric crypto follows asymmetric.
SecurityJWT (JSON Web Tokens) Explained
The signed JSON token format, claims, signatures, where JWTs fit, and the security pitfalls (the alg=none attack, revocation, storage).
SecurityHow OAuth 2.0 Works
The protocol behind "Sign in with Google." Roles, the Authorization Code flow with PKCE, scopes, tokens, and OpenID Connect on top.
SecurityFine-tuning vs RAG vs Prompt Engineering
Three ways to customize LLM behavior. When each makes sense, the trade-offs, and why fine-tuning is overrated for most use cases.
AI Engineering / LLM EngineeringEmbeddings and Semantic Search
How embeddings turn meaning into vectors, how to build semantic search, hybrid search with BM25, reranking, and beyond-text embeddings.
AI Engineering / LLM EngineeringVector Databases Explained
Why traditional databases can't do similarity search. ANN algorithms (HNSW, IVF), the major players (Pinecone, Weaviate, Qdrant, pgvector), filtered and hybrid search.
AI Engineering / LLM EngineeringBuilding a Real-Time Data Pipeline
The four-layer architecture: sources, buffer, stream compute, sinks. Windowing, late data, watermarks, and the operational concerns that make real-time hard.
AI Engineering / Data EngineeringKafka Use Cases and Patterns
Practical Kafka scenarios with concrete topic design, producer/consumer code, and gotchas. Order fanout, CDC, activity tracking, event sourcing, sagas, and when NOT to use Kafka.
AI Engineering / Data EngineeringStream Processing with Kafka
What Kafka actually is (a distributed log). Topics, partitions, consumer groups, exactly-once semantics, and the major stream processing frameworks.
AI Engineering / Data EngineeringChange Data Capture (CDC)
How CDC streams database changes from the transaction log. Why it beats dual-write and polling. Debezium, Maxwell, and the snapshot problem.
AI Engineering / Data EngineeringCDN Deep Dive
How CDNs work. Anycast routing, cache hierarchies, purging strategies, edge compute, and why most modern web apps need one.
System Design / Caching StrategiesCache Invalidation Strategies
The famously hard problem. TTL expiration, event-based, write-through, versioning, tag-based, and the cache stampede problem.
System Design / Caching StrategiesDesigning YouTube
Streaming video at planet scale. Upload pipeline, transcoding, adaptive streaming (HLS/DASH), CDN caching, and live streaming.
System Design / Case StudiesDesigning Dropbox / Google Drive
File sync at scale. Block-level deduplication, sync protocols, conflict resolution, sharing, and bandwidth optimizations.
System Design / Case StudiesDesigning a Web Crawler
Politeness, deduplication (Bloom filters), URL frontier with per-domain rate limits, the dynamic web (JS-rendered pages), and the DNS bottleneck.
System Design / Case StudiesDesigning Search Autocomplete
Tries, prefix indexing, ranking, personalization, and the cached top-K trick that makes autocomplete a single key-value lookup.
System Design / Case StudiesDesigning a News Feed
Beyond chronological order. The three-stage pipeline (candidate generation, ranking, re-ranking), feature stores, ML latency budgets, and the cold start problem.
System Design / Case StudiesDesigning a Notification System
Multi-channel push, email, SMS, in-app at scale. Templates, deduplication, user preferences, throttling, priority queues, and the notification storm problem.
System Design / Case StudiesDesigning Uber's Geo Service
Matching riders with drivers in real time. Geohashing and S2 cells, location updates, the dispatch flow, hot cell mitigations, and surge pricing.
System Design / Case StudiesDesigning Twitter's Timeline
The classic system design problem. Push vs pull, the hybrid fan-out approach for celebrities, storage choices, and what makes the timeline feel real-time.
System Design / Case StudiesDistributed Locks
How distributed locks work, their hidden pitfalls (GC pauses, expired leases), Redlock controversy, fencing tokens, ZooKeeper-style locks, and when you should use a different pattern entirely.
System Design / Distributed SystemsIdempotency in Distributed Systems
Why every distributed system needs idempotent operations, the idempotency key pattern (as used by Stripe and AWS), implementation tactics with database constraints or Redis, and the edge cases.
System Design / Distributed SystemsCircuit Breakers and Bulkheads
How circuit breakers stop cascading failures and bulkheads contain blast radius. Covers the three states, tuning parameters, fallbacks, and combining both patterns for resilient services.
System Design / Distributed SystemsLeader Election
How distributed systems agree on a single leader. Covers the Bully algorithm, Raft, Paxos, ZooKeeper-style locks, fencing tokens, and the failure detection problem at the core of split-brain bugs.
System Design / Distributed SystemsDatabase Replication
A guide to replication topologies (leader-follower, multi-leader, leaderless), sync vs async vs semi-sync, replication lag, failover handling, and split-brain prevention.
System Design / DatabasesSQL vs NoSQL
A practical comparison of SQL and the four main NoSQL families (document, key-value, wide-column, graph). Covers when to pick which, the myths about SQL not scaling, and polyglot persistence.
System Design / DatabasesDatabase Indexing
A practical guide to database indexes: B-trees, hash indexes, LSM-trees, composite and covering indexes, and how to spot a bad index with EXPLAIN.
System Design / DatabasesDesigning a Chat System
An end-to-end design of a real-time chat system at WhatsApp scale. Covers WebSockets, message storage, sequence numbers, fan-out for group chats, presence service, push notifications, and end-to-end encryption.
System Design / Case StudiesMCP Deep Dive
Model Context Protocol from first principles. The host/client/server architecture, JSON-RPC transports, tools, resources, prompts, security, and how MCP turns the M times N integration problem into M plus N.
AI Engineering / LLM EngineeringRAG: Retrieval-Augmented Generation
A practical guide to RAG. Covers why RAG exists, embeddings, chunking strategies, vector databases, retrieval, hybrid search, reranking, and when to use RAG vs fine-tuning.
AI Engineering / LLM EngineeringDatabase Sharding and Partitioning
A practical guide to sharding strategies (range, hash, geographic, directory), shard key selection, hotspot mitigation, cross-shard queries, and resharding. Plus when not to shard.
System Design / DatabasesThe CAP Theorem
A clear walkthrough of the CAP theorem: what consistency, availability, and partition tolerance really mean, why network partitions force a choice between CP and AP, and how real databases like MongoDB, Cassandra, and DynamoDB pick.
System Design / Distributed SystemsConsistent Hashing
How distributed systems split data across servers so that adding or removing one server moves only 1/N of the data instead of breaking everything. Covers the hash ring, virtual nodes, and where it's used in real systems.
System Design / Distributed SystemsDesigning an API Rate Limiter
A comprehensive walkthrough of designing a distributed API rate limiter. Covers fixed window, sliding window, token bucket, and leaky bucket algorithms; deployment options; Redis with Lua for atomic operations; HTTP 429 headers; and production concerns like hot keys and failover.
System Design / Distributed SystemsDesigning a URL Shortener
An end-to-end system design walkthrough. Covers requirements, capacity estimation, Base62 encoding, distributed ID generation, sharding, the thundering herd problem, async analytics, and rate limiting. With full architecture diagrams.
System Design / Case StudiesEventual Consistency Patterns
A comprehensive guide to the four core eventual consistency patterns: Event-based, Background Sync, Saga (choreography and orchestration), and CQRS. With diagrams, real-world examples, failure modes, and a decision guide.
System Design / Distributed SystemsHands-On: Building a Lakehouse with Iceberg
A practical, runnable walkthrough using PyIceberg, DuckDB, and a SQLite catalog. Build a music streaming lakehouse on your laptop. Covers ingestion, queries, schema evolution, time travel, and maintenance.
System Design / DatabasesData Lakehouse Architecture
A comprehensive guide to data lakehouses. Compares warehouses, lakes, and lakehouses. Covers the three building blocks (object storage, open table formats, shared catalog), governance, trade-offs, and a decision tree for choosing.
System Design / DatabasesData Pipelines Explained
A comprehensive guide to data pipelines: the 5 phases, batch vs streaming, ETL vs ELT, Lambda vs Kappa architectures, common tools at every stage, and how to handle failures.
AI Engineering / Data EngineeringWhat Does ACID Mean
A comprehensive guide to ACID properties in databases: Atomicity, Consistency, Isolation, and Durability. Explained with real-world scenarios, diagrams, isolation levels, and the ACID vs BASE trade-off.
System Design / DatabasesImplementing Read Through with Redis
A complete guide to implementing the Read Through caching pattern with Redis and Python. Covers TTL strategies, cache invalidation, error handling, and production considerations.
System Design / Caching StrategiesServing LLMs at Scale
Why vLLM and PagedAttention matter for serving Large Language Models at scale. Covers inference engines, the KV cache problem, and how paging solves it.
AI Engineering / LLM EngineeringCaching Strategies: Overview
A detailed breakdown of the top 5 caching strategies: Cache Aside, Read Through, Write Around, Write Back, and Write Through. With visual diagrams and real-world analogies.
System Design / Caching Strategies