Search

Lessons (20)

• Docker & Containers

  … postgres:17 environment: { POSTGRES USER: app, POSTGRES PASSWORD: secret, POSTGRES DB: shop } volumes: [pgdata:/var/lib/postgresql/data …

• ConfigMaps, Secrets & Storage

  … 50Gi } } mermaid flowchart LR db0[postgres-0] -- d0[(data-postgres-0)] db1[postgres-1] -- d1[(data-postgres-1 …

• Clean Architecture

  … translate between the outside world and the use case js // adapters/PostgresUserRepository.js export class PostgresUserRepository { constructor(pool …

• Clean Architecture in Depth

  … ports How can a use case save an order without knowing about Postgres? It depends on an interface …

• Hexagonal Architecture (Ports & Adapters)

  … the ways out ts // adapters/driven/PostgresLoanRepository.ts export class PostgresLoanRepository implements LoanRepository { constructor(private readonly db: Pool …

• Deployments, ReplicaSets & Rollouts

  … postgres"] db0["postgres-0<br/ 💾 pvc-0"] -- db1["postgres-1<br/ 💾 pvc-1"] -- db2["postgres-2<br/ 💾 pvc …

• Kafka vs RabbitMQ & the Kafka Ecosystem

  … Elasticsearch, S3, Snowflake, BigQuery, MongoDB, Postgres. json { "name": "orders-cdc", "config": { "connector.class": "io.debezium.connector.postgresql.PostgresConnector …

• D — Dependency Inversion Principle

  … new PostgresOrderRepository(pool), mailer: new SesMailer(awsConfig), }); // Tests: plain fakes, no network const sent = []; const testService = new OrderService …

• Database Indexing & Transactions

  … prefer atomic UPDATE … WHERE , then optimistic or pessimistic locking. - Know the isolation levels; Postgres defaults to Read Committed.

• SQL vs NoSQL Databases

  … during a network partition, choose consistency or availability. - Start with Postgres; add specialised stores for specific needs.

• What Is Software Architecture?

  … Use PostgreSQL for the orders service Status Accepted (2026-09-28) Context Orders need multi-row transactions (order …

• Layered (N-Tier) Architecture

  … database server"] DB[(PostgreSQL)] end UI -- API -- DB The classic 3-tier web app has three layers of …

• CQRS & Event Sourcing

  … fraud detection] Tools: EventStoreDB, Axon, Marten (Postgres), or Kafka as the event log. CQRS + event sourcing together They …

• KISS: Keep It Simple, Stupid

  … day one"] direction LR App[One app] -- DB[(Postgres)] end Start with the simplest architecture that works, like …

• Pods

  … busybox:1.36 command: ["sh", "-c", "until nc -z postgres 5432; do echo waiting for db; sleep 2 …

• Serverless Architecture

  … concurrent functions × 1 DB connection each can overwhelm Postgres; use RDS Proxy, Data API, or serverless-friendly DBs …

• Onion Architecture & Clean vs Hexagonal vs Onion

  … cases, Hexagonal ports) └── adapters/ driving: http, cli · driven: postgres, stripe (Hexagonal adapters) How these relate to Layered architecture …

• Scaling, Load Balancing & Rate Limiting

  … Hundreds to thousands of simple requests/second One Postgres primary Thousands of simple writes/second, many more reads …

• Choosing an Architecture

  … Hexagonal + tactical DDD"] oa[HTTP adapter] -- oc((core)) -- ob[(Postgres adapter)] end subgraph Cat["📦 Catalog: vertical slices (mostly …

• Domain-Driven Design: Tactical Patterns

  … application/ │ └── PlaceOrderHandler.ts application services / use cases └── infrastructure/ └── PostgresOrderRepository.ts repository implementation (adapter) Key takeaways - Entities have identity …