Training course · OpenAI Codex · Node.js Back End

OpenAI Codex for Node.js Back-End Developers

Delegate development work with OpenAI Codex: CLI and cloud agent, AGENTS.md, sandboxing, approvals and team PR workflows.

Duration
2 days (14 hrs)
Format
Online or on-site
Language
German or English
Participants
open dates or exclusive for your team
Certificate
Certificate of attendance

Overview

This course connects OpenAI Codex with the everyday processes of Node.js Back End. Participants work on realistic scenarios and leave with prompts, workflows and checklists they can use straight away.

OpenAI Codex is a coding agent that runs both locally, as a command-line tool and IDE extension, and as a cloud agent. Locally, Codex reads your repository, proposes changes and runs commands inside a sandboxed environment. In the cloud, it works on delegated tasks in parallel inside isolated containers and returns results as traceable diffs or pull requests. Over two days you will learn how to combine both modes effectively and how to scope tasks so that the agent can complete them reliably and with minimal back-and-forth.

Control and security sit at the heart of the course. With AGENTS.md you hand Codex project knowledge, build and test commands, and conventions. You configure approval modes and sandboxing so that the agent only does what you permit, and you set up cloud environments with suitable setup scripts. You will also integrate Codex into your pull request workflows, use automated code review, and define team rules on which tasks are delegated and how results are checked before they are merged into the main branch.

For many teams, Node.js is the backbone of REST and GraphQL APIs, real-time services, serverless functions and integration layers. Typical back-end work follows recurring patterns: routes and validation, database access with Prisma, Drizzle or TypeORM, authentication, error handling, logging and tests against real dependencies. AI coding assistants and agents handle these patterns reliably once they understand the project architecture. They generate endpoints from OpenAPI specifications, migrate Express applications to modular structures, write integration tests with Testcontainers and analyse memory leaks or event-loop-blocking operations. This course teaches you to use agents in a way that keeps security, observability and maintainability firmly intact.

The course is delivered live – either online in a virtual classroom or on-site in our training rooms in Munich, Salzburg, Berlin, Augsburg, Hanover, Bremen, Stuttgart and Kaiserslautern. We can also run it exclusively for your team.

Who is this course for?

  • Back-end developers using Express, Fastify or NestJS
  • Full-stack developers responsible for API layers
  • Developers building serverless functions and integration services
  • Software architects designing Node.js-based microservices

Typical challenges we address

  • Organically grown Express apps with no clear layering and scattered error handling
  • Insufficient input validation and weaknesses in authentication and authorisation
  • Performance issues caused by blocking code or memory leaks that are hard to diagnose
  • Missing integration tests against databases, queues and external APIs

What you will be able to do

  • You use Codex locally and in the cloud for the development tasks each mode suits best.
  • You write an AGENTS.md that guides the agent reliably through your project.
  • You configure approval modes and sandboxing to match your security requirements.
  • You delegate tasks to the cloud agent and review the results systematically.
  • Have AI agents build endpoints, data layers and integration tests that fit your Node.js architecture.
  • Use AI to analyse performance problems, memory leaks and security weaknesses in the back end.
  • Define guardrails so that generated back-end code meets your standards for validation, logging and error handling.

Course outline

Day 1

Module 1 Codex at a glance: CLI, IDE and cloud
  • Comparing how Codex works locally and in the cloud
  • Installing the Codex CLI, signing in and starting it in a repository
  • Interactive sessions, non-interactive execution and model choice
  • Distinguishing tasks that suit a coding agent from those that do not
Module 2 Project knowledge with AGENTS.md
  • Building an AGENTS.md with build, test and lint commands
  • Stating conventions, architectural notes and prohibitions precisely
  • Using nested AGENTS.md files for monorepos and sub-projects
  • Checking effectiveness and refining instructions iteratively
Module 3 Sandboxing, approvals and security
  • Choosing approval modes deliberately, from read-only to largely autonomous
  • Understanding sandbox boundaries for file system and network access
  • Handling secrets, dependencies from the internet and prompt injection
  • Configuration files for team standards and safe defaults
Module 4 Delegating tasks to the cloud agent
  • Configuring cloud environments with setup scripts and dependencies
  • Writing tasks with a clear goal, context and acceptance criteria
  • Launching several tasks in parallel and comparing the results
  • Using logs and test output to understand the proposed solutions

Day 2

Module 5 PR workflows and code review in the team
  • Turning results into pull requests and requesting follow-up changes
  • Using automated Codex code review on GitHub
  • Embedding Codex in scripts and CI pipelines
  • Setting team rules for delegation, review duties and accountability
Module 6 Practice lab: Node.js Back End
  • API endpoints from specifications
  • Database access and migrations
  • Integration tests with Testcontainers
  • Restructuring Express applications
  • Analysing performance and memory leaks
  • Security hardening
Module 7 Data protection, quality & transfer to daily work
  • Back ends often process personal data: production data, logs and database dumps should never go into prompts unfiltered, and credentials from environment variables must stay excluded. Vet new npm dependencies for supply-chain risk and licensing, and for critical services take the security requirements of NIS2 into account.
  • Ground rules for safe AI use in your team
  • Checking results: facts, sources, tests and the four-eyes principle
  • Personal action plan for the next 30 days
  • Open questions, outlook and resources for further learning

Practical scenarios from your field

API endpoints from specifications

From an OpenAPI or GraphQL schema, the agent generates routes or resolvers, validation with Zod or class-validator, service layers and consistent error responses – all matching your existing project structure.

Database access and migrations

The AI models schemas for Prisma, Drizzle or TypeORM, writes migrations, optimises queries with indexes and transactions and explains the impact on existing data before rollout.

Integration tests with Testcontainers

The assistant writes tests that spin up real databases, Redis or message brokers in containers, seed data and exercise API endpoints end to end with Supertest against realistic dependencies.

Restructuring Express applications

Monolithic Express projects are split into modules with controllers, services and repositories, middleware is standardised and callback code moved to async/await – backed by existing and new tests.

Analysing performance and memory leaks

The AI interprets heap snapshots, profiler output and logs, identifies operations blocking the event loop and proposes fixes such as streams, worker threads or caching.

Security hardening

The agent reviews authentication flows using JWTs or sessions, adds rate limiting, secure HTTP headers and input validation and checks the code against the OWASP API security risks.

Possible hands-on projects

Webhook relay service

A Fastify service that receives webhooks from various SaaS providers, verifies signatures, queues events and forwards them to internal systems with retry logic.

Job queue with dashboard

A background-processing service built on BullMQ and Redis, with retry strategies, a monitoring UI and integration tests. Failed jobs can be inspected and retried directly from the UI.

API gateway prototype

A lean gateway service with authentication, rate limiting, request logging and routing to several back-end services, developed entirely by an AI agent.

Prerequisites

You have hands-on programming experience, are comfortable with Git and the command line, and know pull-request-based workflows. Back-end development experience with Node.js and JavaScript or TypeScript, plus a working knowledge of databases, HTTP and Git.

Technical requirements

Your own laptop with a terminal, Git and a Node.js runtime; a ChatGPT plan with Codex access or an OpenAI API key, plus a GitHub account for the cloud exercises.

Data protection & compliance

Back ends often process personal data: production data, logs and database dumps should never go into prompts unfiltered, and credentials from environment variables must stay excluded. Vet new npm dependencies for supply-chain risk and licensing, and for critical services take the security requirements of NIS2 into account.

Suggested dates

All dates are suggestions – your preferred date is always possible.

  • Tue, 24 November 2026 – Wed, 25 November 2026 Online Request
  • Wed, 2 December 2026 – Thu, 3 December 2026 Munich Request
  • Tue, 8 December 2026 – Wed, 9 December 2026 Online Request
  • Thu, 21 January 2027 – Fri, 22 January 2027 Online Request
  • Wed, 3 February 2027 – Thu, 4 February 2027 Berlin Request
  • Tue, 9 February 2027 – Wed, 10 February 2027 Online Request

Frequently asked questions

When should I use Codex locally and when in the cloud?

Locally you work interactively and close to the code, for example when debugging or making exploratory changes where you want to follow every step. The cloud agent suits well-defined tasks that can run independently, such as adding tests or fixing smaller bugs. You can start several of these in parallel and review each one as a pull request.

What belongs in a good AGENTS.md?

A good AGENTS.md explains how the project is built, tested and checked, which conventions apply and which areas must not be touched. It is concise, concrete and kept up to date. Notes on architecture and common pitfalls also help. During the course you write an AGENTS.md for a project of your own and test how it changes the agent’s behaviour.

How safe is it to let Codex run commands?

By default Codex works inside a sandbox with restricted file and network access and asks for approval before risky steps. You decide how much autonomy to grant through approval modes and configuration. In the course you learn to choose these settings deliberately and to limit risks such as prompt injection or running unfamiliar dependencies.

Is the course suitable for both NestJS and Express?

Yes. We work with framework-neutral principles such as layering, validation and testability, and show with examples how to capture the conventions of Express, Fastify or NestJS in instruction files. That way the assistant generates code that fits your framework and your project structure rather than generic boilerplate.

How do I stop the AI from producing insecure back-end code?

Through clear rules, automated checks and critical review. On the course you define security rules for validation, authentication and data access, plug in static analysis and dependency scanning, and learn to spot typical weaknesses in generated code, such as missing authorisation checks or unsafe queries.

How much does “OpenAI Codex for Node.js Back-End Developers” cost?

The course costs a flat €949 plus VAT per participant – whether online or on-site. This includes 2 training day(s) with a live trainer, course materials, a lab environment and a certificate of attendance.

Can I suggest my own date?

Yes. Our suggested dates are just a guide. In the request form you can always describe your preferred date or period in free text – we check availability and confirm within one working day.

Is the course online or on-site?

Both are possible: live online in a virtual classroom or on-site in Munich, Salzburg, Berlin, Augsburg, Hanover, Bremen, Stuttgart or Kaiserslautern. We can also run the course exclusively for your team.

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