Free Programming & Engineering Courses

Structured courses with explanations, comparison tables and code in several stacks — from REST API design and GraphQL to idempotency, event sourcing, distributed systems, payments and LLM integration.

Engineering Fundamentals

API Architecture and Integration Design REST, GraphQL, gRPC, events and webhooks; contract-first OpenAPI; pagination, errors, idempotency and versioning; gateways, BFFs… API Design · 10 lessons API Platform & Lifecycle Run APIs as products: contract-first OpenAPI 3.1 and AsyncAPI 3, mocks, Spectral governance, breaking-change CI, contract… API Design · 20 lessons API Security in Depth The OWASP API Security Top 10 (2023) in practice: BOLA, BOPLA, BFLA, OAuth 2.1 and RFC 9700, token validation, fine-grained… Web Security & WAF · 20 lessons Authentication & Authorization Architecture Design identity for modern systems: passwords and sessions, OAuth 2.0 and OIDC, tokens, MFA and passkeys, SSO, authorization… Authentication · 10 lessons Caching and Performance Engineering Caching layers, cache patterns and invalidation, HTTP caching and CDNs, Redis, measuring performance, database tuning, scaling… Caching · 10 lessons Database Caching at Scale Caching for high-traffic systems without stale or leaked data: cache-aside done right, the stale-set race, versioned keys, TTLs… Caching · 20 lessons Design Patterns, Explained Simply SOLID and all 23 classic design patterns, plus the patterns modern frameworks are built on, explained in plain language with… Design Patterns · 36 lessons Distributed Systems for Backend Engineers The theory behind modern backends: clocks and ordering, consistency models, CAP/PACELC, replication, partitioning, consensus,… Distributed Systems · 20 lessons ETL and Data Pipelines Build data pipelines that are correct, re-runnable and cheap to operate, through real production problems: ETL vs ELT, batch vs… Data Engineering · 22 lessons Event Sourcing & CQRS Model domains as events: event modeling, aggregates, event stores, CQRS and projections, eventual consistency in the UI,… Messaging & Queues · 20 lessons GraphQL in Production Design, secure and operate GraphQL APIs: schema design and nullability, mutations and errors, DataLoader and cost limits,… API Design · 20 lessons Idempotency & Retry-Safe Systems Make every operation safe to retry: idempotent design, Idempotency-Key implementation, timeouts and deadlines, backoff with… Reliability · 20 lessons Integrating LLM APIs Ship LLM features like any other production dependency: models and tokens, prompts as code, streaming, structured outputs, tool… AI Integration · 20 lessons Messaging, Events and Email Systems Queues, streams and background jobs, delivery guarantees, outbox and CDC, event design, sagas, Kafka in practice, notification… Messaging & Queues · 10 lessons Mobile API Best Practices Design backends for iOS and Android: screen-shaped responses, payload and battery efficiency, offline-first and delta sync,… Mobile · 20 lessons Observability and Operations Logs, metrics and traces with OpenTelemetry, SLOs and burn-rate alerting, incident response, runbooks, telemetry pipelines, safe… Logging & Observability · 10 lessons Payments & Money APIs Build correct money systems: representing money, how card payments work, PSP integration models and PCI scope, SCA, payment… Payments · 20 lessons Queues & Background Processing in Depth Messaging models, message design, ordering, acknowledgements, broker choice, job frameworks by stack, retries and DLQs, poison… Messaging & Queues · 20 lessons Rate Limiting, Quotas & Abuse Protection Protect APIs with the right algorithms (windows, token bucket, GCRA), distributed limiters, RateLimit headers, quotas and plans,… Reliability · 20 lessons Real-Time APIs WebSockets, SSE, long polling and WebTransport; designing, receiving and securing webhooks; fan-out, presence, connection… Messaging & Queues · 20 lessons Request Lifecycle: How Web Frameworks Handle a Request Follow a request from the socket to the response in the frameworks you use: the proxy and server chain, PHP-FPM, WSGI, ASGI and… Web Framework Internals · 17 lessons Resilience Patterns Design systems that survive failure: failure modes and metastability, timeout budgets, circuit breakers, bulkheads, load… Reliability · 20 lessons REST APIs in Depth Industry-standard REST API design for any stack: resource modeling, HTTP semantics, status codes, JSON conventions, pagination,… API Design · 20 lessons Scaling Databases & Data Consistency Scale relational databases the way high-traffic products do: find the queries that matter, index for real workloads, fix N+1 and… Databases & Transactions · 20 lessons Software Architecture Foundations Modern architecture practices for scalable systems: event-driven design, microservices, DDD, consistency, and resilience patterns. System Design Problems · 5 lessons Transactions, Locking & Concurrency in Code Real production bugs and their fixes: transaction boundaries, framework pitfalls, long transactions, pool exhaustion, isolation… Databases & Transactions · 20 lessons Web Security and WAF The OWASP Top 10 in practice: injection, XSS and CSP, CSRF and CORS, access control and SSRF, plus TLS and headers, WAFs and… Web Security & WAF · 10 lessons

Engineering Leadership

The Engineering Manager Handbook (Development Manager) A practical course for engineering managers and development managers: the manager operating system, the first 90 days with a new… Engineering Management · 20 lessons The Team Lead Handbook A practical course for team leads: the move from engineer to lead, team charters and working agreements, effective 1:1s,… Team Lead · 20 lessons The Tech Lead Handbook A practical course for new and experienced tech leads: what the role owns, the first 90 days, balancing code and leadership,… Tech Lead · 20 lessons

Programming

FastAPI: From Basics to Production Build production-ready Python APIs with FastAPI: Pydantic v2, dependency injection, async SQLAlchemy and Alembic, JWT auth,… FastAPI · 35 lessons Flask API Fundamentals Build lightweight Python APIs with Flask routing, request handling, JSON responses, and blueprints. Flask · 4 lessons Go Programming Fundamentals A hands-on path through Go syntax, tooling, and concurrency, built from the official Go documentation and tour. Backend · 6 lessons Modern HTML5 in Production Fix the real-world problems HTML is responsible for: pages screen-reader users can't navigate, controls keyboards can't reach,… HTML & CSS · 15 lessons PHP 7: Maintaining and Upgrading Legacy Apps Work confidently in PHP 7 codebases: language features, testing and refactoring legacy code, security hardening, and a safe path… PHP 7 · 35 lessons PHP 8: Modern PHP Development From PHP 8 syntax and types to enums, property hooks, Composer, PDO, security, testing and production deployment with OPcache,… PHP 8 · 37 lessons Python Programming Deep Dive A structured path from Python syntax to practical software habits, based on the official Python tutorial. Python · 6 lessons React: From Components to Production Modern React 19 with TypeScript: components, state and effects, forms and Actions, TanStack Query, React Router, performance and… React Developer · 36 lessons Spring Boot: From Basics to Production Build and run Java 21 services with Spring Boot: dependency injection, REST APIs, validation, Spring Data JPA, Spring Security… Java Developer · 35 lessons

Cloud

Java Serverless on AWS Lambda Run production Java on AWS Lambda through real failures: event deserialization, where JVM cold-start time goes, SnapStart… Java Serverless · 14 lessons Node.js Serverless on AWS Lambda Build and run production Node.js and TypeScript services on AWS Lambda through real production problems: async handlers and cold… Node.js Serverless · 25 lessons Python Serverless on AWS Lambda Run production Python on AWS Lambda through real failures: leaking module state, native wheels that will not load, slow… Python Serverless · 14 lessons Terraform in Production Running Terraform safely with a team: locked remote state on AWS, Azure and GCP, secrets kept out of state, drift detection,… Infrastructure as Code · 11 lessons

AI

Native AI Engineering: LLMs, RAG & Agents A practical introduction to building applications with large language models, retrieval, and agents, drawing on widely used open… Native AI Engineering · 6 lessons

Other

Career Growth Foundations A practical starter course covering job search planning, learning habits, and career confidence. 6 lessons