Backend Course

Lesson 1 • How the Web Works

Covers DNS resolution, TCP/IP, and HTTP/HTTPS fundamentals. Provides the network context every backend decision depends on.

Lesson 2 • Backend Roles and Responsibilities

Defines what backend engineers own: data, logic, security, and performance. Sets professional expectations for the entire course.

Lesson 3 • Development Environment Setup

Configures a local backend workspace with runtime, package manager, and version control. Ensures every learner starts from a consistent baseline.

Lesson 1 • ORM Usage and Pitfalls

Maps database tables to application models using an ORM and identifies N+1 query problems. Balances developer productivity with query efficiency.

Lesson 2 • SQL Query Writing

Covers SELECT, INSERT, UPDATE, DELETE, and JOIN operations. Connects query syntax to real data retrieval and mutation tasks.

Lesson 3 • NoSQL and Document Stores

Contrasts document, key-value, and column-family models with relational databases. Guides appropriate database selection per use case.

Lesson 4 • Schema Migrations and Versioning

Manages schema changes through versioned migration files and rollback strategies. Ensures safe schema evolution in production environments.

Lesson 1 • Routing and Controllers

Maps URL patterns to handler functions and organises controllers by resource. Establishes the structural pattern used throughout the course.

Lesson 2 • API Versioning Strategies

Compares URI, header, and query-param versioning approaches. Enables backward-compatible API evolution over time.

Lesson 3 • REST Architectural Principles

Explains the six REST constraints and resource naming conventions. Grounds API design decisions in architectural reasoning.

Lesson 4 • Error Handling and HTTP Semantics

Implements centralised error handling and maps exceptions to correct HTTP status codes. Produces consistent, client-friendly error responses.

Lesson 1 • JSON Web Tokens in Depth

Constructs, signs, and validates JWTs and manages token expiry and refresh. Enables stateless authentication across distributed services.

Lesson 2 • Authentication Concepts and Flows

Distinguishes authentication from authorisation and maps common identity flows. Establishes vocabulary for all security decisions in this chapter.

Lesson 3 • Password Security and Hashing

Applies adaptive hashing algorithms and salting to protect stored credentials. Prevents credential exposure from database breaches.

Lesson 4 • Securing API Endpoints

Applies authentication guards, rate limiting, and CORS policies to API routes. Hardens the API surface against common attack vectors.

Lesson 1 • HTTP Caching and ETags

Configures Cache-Control headers, ETags, and conditional requests to reduce server load. Uses the HTTP layer for zero-cost response delivery.

Lesson 2 • Caching Concepts and Layers

Maps caching opportunities across in-process, distributed, and CDN layers. Establishes a framework for choosing the right cache per scenario.

Lesson 3 • Database Query Optimisation

Uses query plans, indexes, and denormalisation to speed up slow queries. Directly reduces the most common backend performance bottleneck.

Lesson 4 • Profiling and Benchmarking APIs

Measures API throughput, latency percentiles, and memory usage under load. Provides data-driven evidence for optimisation decisions.

Lesson 1 • Synchronous vs. Asynchronous Patterns

Contrasts blocking request handling with deferred processing and event-driven models. Motivates queue adoption for latency-sensitive APIs.

Lesson 2 • Error Handling in Async Pipelines

Manages failures across worker processes with dead-letter queues and alerting. Ensures no job is silently lost in production.

Lesson 3 • Scheduled and Recurring Jobs

Configures cron-style schedules for periodic tasks and handles missed-run recovery. Automates maintenance and reporting workflows.

Lesson 4 • Message Queue Fundamentals

Explains producers, consumers, exchanges, and queues in a message broker. Provides the mental model for all queue-based implementations.

Lesson 1 • GraphQL API Design

Defines schemas, resolvers, and mutations in GraphQL and compares it to REST. Enables flexible, client-driven data fetching.

Lesson 2 • API Documentation and Contracts

Generates OpenAPI specifications and enforces contract testing between services. Aligns frontend and backend teams on shared API expectations.

Lesson 3 • Microservices Communication Patterns

Compares synchronous and asynchronous inter-service communication and handles partial failures. Builds resilient service meshes.

Lesson 4 • gRPC and Protocol Buffers

Defines service contracts in Protocol Buffers and implements gRPC server and client. Delivers high-performance binary communication between services.

Lesson 1 • Containerisation with Docker

Packages backend services into Docker images and orchestrates multi-container environments. Eliminates environment inconsistency between development and production.

Lesson 2 • Metrics, Alerts, and Dashboards

Instruments services with RED metrics and configures actionable alerts. Provides real-time visibility into service health and SLO compliance.

Lesson 3 • Structured Logging and Tracing

Emits structured logs and distributed traces to correlate events across services. Enables rapid root-cause analysis in production incidents.

Lesson 4 • CI/CD Pipeline Construction

Automates build, test, and deployment stages in a continuous delivery pipeline. Reduces manual release risk and accelerates delivery frequency.