Software Development
Building Production APIs with Python and FastAPI
Python developers often ship an API that works in development and then meets real traffic, real clients, and real error cases. This course covers async request handling, Pydantic validation, dependency injection, authentication, versioned OpenAPI contracts, structured errors, automated testing, and containerized deployment.
Overview
Practical learning for workplace transfer.
The gap between a working FastAPI endpoint and a production API is filled with the things tutorials skip: what happens when a downstream call blocks the event loop, how a client learns that a field changed, where authentication tokens are verified, and what an error body must contain for an integration partner to debug without calling support. Participants build one service across the course, adding typed request and response models, injected dependencies and database sessions, token-based authorization, a published OpenAPI contract, a test suite that runs without a live database, and a container image ready for deployment.
Prerequisites
Working Python knowledge including functions, classes, and package management. Familiarity with HTTP and relational databases is helpful but not required.
Objectives
- Build asynchronous FastAPI endpoints without blocking the event loop.
- Model request and response payloads with Pydantic validation and typed schemas.
- Manage database sessions, configuration, and clients through dependency injection.
- Implement token-based authentication and per-route authorization rules.
- Publish and version an OpenAPI contract that integration partners can build against.
- Test, containerize, and deploy the service with health checks and structured logging.
Target audience
- Python developers building or maintaining backend services
- Backend engineers migrating from Flask or Django REST Framework
- Data and machine learning engineers exposing models as services
- Integration developers publishing APIs to partners and internal teams
- Full-stack developers responsible for their own service layer
- Technical leads setting API standards across Python teams
Program outline
A clear structure for the learning journey.
Program outline
Outline points are grouped in one designed block instead of being treated as separate module cards.
Module 1: FastAPI Fundamentals and Async Request Handling
Routing, path and query parameters, and the request lifecycle
Async and synchronous endpoints and what actually blocks the event loop
Background tasks, concurrency limits, and long-running operations
Project structure for a service that will grow beyond one file
Module 2: Data Validation and Schema Design with Pydantic
Request and response models, field constraints, and custom validators
Separating internal domain models from public API schemas
Serialization, aliases, and handling optional and nullable fields
Validation errors that tell the caller exactly what to correct
Module 3: Dependency Injection, Persistence, and Configuration
The dependency system: scopes, overrides, and shared resources
Database sessions, connection pooling, and transaction boundaries
Settings, secrets, and environment configuration without hard-coding
Injecting HTTP clients, caches, and third-party services for testability
Module 4: Authentication, Authorization, and API Protection
OAuth2 password and bearer flows, token issuance, and verification
Route-level and resource-level authorization rules
CORS, rate limiting, and request size and timeout controls
Credential handling, key rotation, and audit-relevant request logging
Module 5: Contracts, Errors, and API Versioning
Generated OpenAPI documentation and keeping it accurate as code changes
Consistent error envelopes, status codes, and problem details
Versioning strategies and deprecating an endpoint without breaking clients
Pagination, filtering, and idempotency for write operations
Module 6: Testing, Packaging, and Production Deployment
Testing endpoints with pytest, test clients, and dependency overrides
Fixtures and fakes that remove the need for a live database
Containerizing the service with Uvicorn and a production process manager
Health checks, structured logging, and metrics for a deployed service
Materials provided
- Course workbook, annotated code samples, and reference notes
- Hands-on lab environment and starter repositories
- Exercises, checklists, and reusable code templates
- 4D Certificate of Completion
- Post-course technical guidance
Training Options
Programs can be delivered in-house, online, or in a blended format depending on your team's schedule, location, and learning objectives. When an external certificate or exam is included, certification rules and fees remain under the relevant awarding body's policies, while 4D provides the training and preparation support.
Why choose 4D
4D shapes this course around the integrations your service must actually support, whether internal consumers, partner systems, or model-serving endpoints. Participants finish with a running FastAPI service, a published OpenAPI contract reviewed against your integration requirements, and a test and deployment setup their team can extend immediately.
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