Engineering Topics
Everything about one topic in one place — lessons, decision guides, recipes and interview questions, across stacks.
Logging & Observability
Structured logs, metrics, traces, SLOs and alerting that let you understand production.
Authentication
Passwords, sessions, JWTs, OAuth 2.0/OIDC, MFA and passkeys: proving who a user is.
Authorization
RBAC, ABAC, ReBAC, scopes, multi-tenancy and object-level checks: deciding what a user may do.
Caching
Cache-aside, invalidation, HTTP caching, CDNs and Redis, plus each framework's caching layers.
Web Security & WAF
OWASP Top 10, XSS, CSRF, injection, SSRF, security headers, WAFs, rate limiting and bot protection.
API Design
REST, GraphQL and gRPC, pagination, idempotency, versioning, errors and webhooks.
Databases & Transactions
Transactions and isolation, indexing, N+1, locking, replication, sharding and migrations.
Messaging & Queues
Queues vs streams, delivery guarantees, idempotent consumers, outbox, sagas and background jobs.
Performance & Scalability
Profiling, latency vs throughput, load balancing, autoscaling, resilience and capacity planning.
Testing
Unit, integration and E2E tests, test doubles, flaky tests, contract and property-based testing.
CI/CD & Deployment
Pipelines, Docker, Kubernetes, zero-downtime deploys, migrations, feature flags and rollbacks.
System Design Problems
Worked designs: URL shortener, rate limiter, chat, news feed, payments, ticketing and more.
Engineering Leadership
Tech lead, team lead and engineering (development) manager: technical direction, 1:1s and feedback, delivery and flow, hiring, performance, team design — with interview questions for each role.
Design Patterns
SOLID, the 23 classic design patterns and the modern ones frameworks are built on, explained simply with runnable Python, TypeScript, Java and PHP examples, plus the interview questions and a quiz.
ETL and Data Pipelines
Moving data reliably from production systems to warehouses: ETL vs ELT, change data capture, idempotent loads, late data, dimensional modelling, dbt, orchestration, data quality and cost, with interview questions and a quiz.
Request Lifecycle in Web Frameworks
What happens between the socket and the response in Laravel, Symfony, Django, Flask, FastAPI, Express, NestJS, Next.js, Spring and the browser: middleware, routing, guards, filters, error handling and post-response work, with interview questions and a quiz.