Backend Fundamental Components

2026/05/22

Each doc covers one fundamental backend-component category with the same structure: what problem it solves, why frameworks solve it differently, a hands-on example, FAQs for L5/L6/L7 technical interviews, staff engineer prep notes, and gaps worth covering.

Databases
Transactional (OLTP) and analytical (OLAP/columnar) databases — what they are, how they work at the byte level, when to pick which.2026/05/22 OLAP / Analytical Data Stores
How to build an OLAP system — Snowflake, BigQuery, ClickHouse, Pinot, Druid, Iceberg lakehouses.2026/05/22 Object Storage
S3, GCS, Azure Blob — blob storage as a foundation for lakehouses and archives.2026/05/22 Distributed Cache
Redis, Memcached — in-memory key-value caching.2026/05/22 Vector Database
Pinecone, Milvus, pgvector — embedding similarity search.2026/05/22 Time-Series Database
Prometheus, InfluxDB, TimescaleDB — timestamp-keyed data.2026/05/22 Search
Elasticsearch, OpenSearch, Solr, inverted index, BM25.2026/05/22 Message Queue & Streaming
Kafka, Pulsar, RabbitMQ, SQS, NATS.2026/05/22 Stream Processing
Flink, Samza, Kafka Streams, Spark Streaming.2026/05/22 Workflow Engine
Temporal, Cadence, Airflow, Step Functions.2026/05/22 Coordination Service
ZooKeeper, etcd, Consul, Raft, Paxos.2026/05/22 RPC
gRPC, Thrift, REST, schema evolution.2026/05/22 Load Balancer
L4, L7, NGINX, Envoy, API gateway.2026/05/22 CDN
CloudFront, Akamai, Fastly, edge caching.2026/05/22 Observability
Prometheus, Jaeger, OpenTelemetry, ELK.2026/05/22 Auth & Identity
OAuth 2.0, OIDC, JWT, secrets.2026/05/22