Why Dev Environments Still Suck in 2025

Spinning up a dev environment should take seconds. But for most developers, it still involves:

• Cloning repos

• Installing language runtimes

• Fixing broken dependencies

• Matching the team’s tooling

• Configuring Docker, linting, secrets, test scripts...

I wanted to see if that entire setup process could be done by just prompting an LLM agent.

So I gave it a public repo, typed one sentence, and let it build everything.

What I Asked the LLM

"Set up a full GitHub Codespaces devcontainer for this repo. It uses Node.js, MongoDB, and needs Postman CLI for testing."

The repo had only a basic package.json and a README.md with instructions.

What the LLM Agent Generated

1. devcontainer.json

{
  "name": "node-mongo-api",
  "image": "mcr.microsoft.com/devcontainers/javascript-node",
  "features": {
    "ghcr.io/devcontainers/features/mongodb:1": {},
    "ghcr.io/devcontainers/features/github-cli:1": {},
    "ghcr.io/devcontainers/features/postman-cli:1": {}
  },
  "postCreateCommand": "npm install && echo 'Ready to go!'",
  "customizations": {
    "vscode": {
      "extensions": [
        "dbaeumer.vscode-eslint",
        "ms-azuretools.vscode-docker"
      ]

2. Dockerfile

FROM node:18
WORKDIR /app
COPY . .
RUN npm install -g postman
RUN npm install
CMD ["npm", "run", "dev"]

3. .devcontainer Folder Structure

Everything worked out of the box in GitHub Codespaces, no changes needed.

Onboarding Time: Human vs AI

Onboarding new devs now feels like magic:

“Clone, click Codespace, code.”

Lessons Learned

LLMs Are Great At:

• Reading README/setup instructions

• Detecting language + dependencies

• Generating Dockerfiles + devcontainer.json from context

• Pre-installing tools and extensions

LLMs Still Struggle With:

• Advanced shell scripting in postCreateCommand

• Auth setup (e.g., injecting API keys securely)

• Picking the right linter or formatter without clear repo hints

• Handling polyglot repos with mixed language tooling

Final Takeaway

LLMs can take you from "zero to coding" in under 2 minutes. That makes them not just helpful — but revolutionary for:

• Bootcamps

• Open-source projects

• Onboarding new engineers

• Testing ideas in isolated sandboxes

We’re entering a world where your dev environment is just a prompt away.

If your team still takes hours to onboard, you're probably doing it wrong.