// tech stacks

Tech Stacks
Deep Dives

The building blocks of modern systems — messaging, storage, infra, and APIs — broken down for interviews.

01
Tech Stacks WebSockets & Realtime Full-duplex real-time, WebSockets vs SSE vs long-polling, and scaling with a pub/sub backplane.
Oct 04, 2023↗
02
Tech Stacks gRPC & Protobuf Contract-first RPC, Protocol Buffers, HTTP/2, streaming, and gRPC vs REST vs GraphQL.
Oct 02, 2023↗
03
Tech Stacks API Gateway & Service Mesh Cross-cutting concerns, north-south vs east-west, the BFF pattern, and the sidecar mesh.
Sep 30, 2023↗
04
Tech Stacks DNS Resolution flow, record types, caching and TTL, GeoDNS and anycast, and reliability.
Sep 28, 2023↗
05
Tech Stacks Observability The three pillars (metrics, logs, traces), distributed tracing, SLOs, and alerting.
Sep 26, 2023↗
06
Tech Stacks CI/CD CI vs delivery vs deployment, pipeline stages, immutable artifacts, and rollout strategies.
Sep 24, 2023↗
07
Tech Stacks Docker & Containers Containers vs VMs, namespaces and cgroups, image layers, the Dockerfile, and registries.
Sep 22, 2023↗
08
Tech Stacks CDN Edge caching, PoPs and anycast, cache-control and TTLs, invalidation, and dynamic acceleration.
Sep 20, 2023↗
09
Tech Stacks Vector Databases Embeddings, approximate nearest neighbor (HNSW/IVF), RAG, and hybrid search.
Sep 18, 2023↗
10
Tech Stacks Database Indexing B-tree vs LSM-tree, clustered vs secondary, composite and covering indexes.
Sep 16, 2023↗
11
Tech Stacks Elasticsearch The inverted index, analyzers, BM25 relevance, shards and replicas, and queries vs filters.
Sep 14, 2023↗
12
Tech Stacks Object Storage & S3 Object vs block/file, the flat namespace, erasure-coded durability, presigned URLs, and tiers.
Sep 12, 2023↗
13
Tech Stacks Redis In-memory data structure store — data types, persistence, eviction, replication, and Cluster.
Sep 10, 2023↗
14
Tech Stacks GraphQL & REST Comparison A deep technical comparison — resources, API design, resolvers, and tradeoffs.
Sep 08, 2023 ↗
15
Tech Stacks Spark Join Strategy Broadcast, shuffle hash, and sort-merge joins — picking the right strategy at scale.
Jul 15, 2023 ↗
16
Tech Stacks OAuth 2.0 Authorization flows, tokens, scopes, and the four grant types demystified.
Jun 17, 2023 ↗
17
Tech Stacks NoSQL Key-value, document, column-family, and graph stores — when SQL isn't enough.
Apr 02, 2023 ↗
18
Tech Stacks Message Queue Async decoupling, delivery guarantees, and queue vs commit-log semantics.
Apr 02, 2023 ↗
19
Tech Stacks Sharding Horizontal partitioning — hash vs range, resharding, and the hot-key problem.
Apr 02, 2023 ↗
20
Tech Stacks Caching Cache strategies, eviction policies, write-through vs write-back, and avoiding stampedes.
Apr 02, 2023 ↗
21
Tech Stacks Load Balancing L4 vs L7, balancing algorithms, health checks, and how traffic spreads across servers.
Apr 02, 2023 ↗
22
Tech Stacks Kubernetes (k8s) Container orchestration — pods, deployments, services, and the control plane explained.
Apr 01, 2023 ↗
23
Tech Stacks Apache Kafka Distributed event streaming — pub/sub, partitions, replicas, acks, and exactly-once delivery.
Mar 31, 2023 ↗