Building a GraphQL Endpoint with Deno Course Syllabus

Overview: This hands-on course guides you through building a production-ready GraphQL API using Deno and TypeScript. You'll progress from setting up your environment to deploying a secure, containerized service with support for both PostgreSQL and MongoDB. The course blends core concepts with practical implementation, featuring real-world tools like Docker, GraphQL Playground, and automated testing. With approximately 4 hours of content, you’ll gain confidence in modern backend development using Deno’s secure runtime and type-safe ecosystem.

Module 1: Introduction to Deno, TypeScript & GraphQL

Estimated time: 0.5 hours

• Understand Deno’s secure, modern runtime and its advantages over Node.js
• Explore built-in TypeScript support in Deno
• Learn GraphQL fundamentals: types, queries, mutations, and resolvers
• Run a "Hello, GraphQL" example and interact with GraphQL Playground

Module 2: Setting Up Your Deno GraphQL Server

Estimated time: 0.75 hours

• Use the oak framework to create an HTTP server in Deno
• Integrate GraphQL middleware using oak-graphql or gql
• Create a functional /graphql endpoint
• Test basic query responses using GraphQL Playground

Module 3: Schema Design & Resolver Implementation

Estimated time: 1 hour

• Define GraphQL type definitions using Schema Definition Language
• Design query and mutation structures
• Implement resolver functions for user operations
• Build createUser, getUser, and listUsers resolvers

Module 4: Integrating PostgreSQL with Deno

Estimated time: 0.75 hours

• Set up a PostgreSQL client in Deno
• Perform schema migrations and define database tables
• Connect GraphQL resolvers to PostgreSQL for CRUD operations
• Understand SQL vs. NoSQL tradeoffs in API design

Module 5: Integrating MongoDB with Deno

Estimated time: 0.75 hours

• Configure the MongoDB driver for Deno
• Model document structures and manage collections
• Implement resolvers for a Post collection
• Compare table-based and document-based data persistence

Module 6: Testing & Tooling

Estimated time: 0.5 hours

• Write unit tests for resolver logic
• Validate schema correctness using testing tools
• Use GraphQL Playground to test queries and mutations
• Apply linting and formatting for code quality

Module 7: Deployment & Dockerization

Estimated time: 0.5 hours

• Create a Dockerfile for a Deno application
• Use multi-stage builds for efficient containers
• Configure environment variables for different deployments
• Run the GraphQL service with Docker Compose and linked databases

Module 8: Capstone – Feature Extension & Best Practices

Estimated time: 0.5 hours

• Add authentication using JWT and implement a login mutation
• Apply security best practices to protect the GraphQL endpoint
• Implement pagination, batching, error handling, and rate limiting

Prerequisites

• Familiarity with TypeScript syntax and basics
• Understanding of GraphQL concepts (types, queries, mutations)
• Basic knowledge of databases (SQL or NoSQL)

What You'll Be Able to Do After

• Build a full-featured GraphQL API using Deno and TypeScript
• Connect and persist data using both PostgreSQL and MongoDB
• Test and validate resolver logic and schema integrity
• Containerize and deploy a Deno GraphQL service using Docker
• Apply security and performance best practices in API design