Set Up Complete Development Environments from Scratch

Environment Setup Guide organizes developer setup into requirements, inspection, installation, configuration, and verification. It identifies the programming language and version, package manager, database, development tools, environment variables, and configuration files a project needs. Before adding software, it checks what is already installed and then provides platform-specific installation guidance.

Supported environments include Node.js projects, Python applications with virtual environments, and a Docker Compose development stack. The goal is a setup that can be checked with version commands, basic tool operations, database connections, and application startup rather than an installation sequence with no evidence that it worked.

Use it when starting a project, onboarding a teammate, moving to another machine or operating system, troubleshooting environment problems, or writing setup instructions. Document prerequisites, common errors, and verification steps, and test the instructions on a clean system.

Historical version examples are not current support recommendations. Select versions using project lockfiles, runtime constraints, and official support matrices, and do not assume a newer major release is compatible. Dependency installation can execute lifecycle scripts. Protect secret environment files and exclude them from version control. Confirm a disposable or local database target before applying the example's project-specific migrations.

Inputs include the operating system, project requirements, installed-tool inventory, dependency files, and required configuration. Outputs include installation instructions, environment-file guidance, shell and IDE configuration, and steps for confirming that the project starts correctly. An initial inventory example is:

node --version
python --version
git --version
docker --version

Node.js guidance covers dependencies, environment variables, development startup, and npm permission problems. Python guidance creates and activates a virtual environment, installs requirements, configures application variables, and starts a Flask example. Prefer project-local dependencies or virtual environments over unnecessary global installation, and use nvm or pyenv where appropriate.

Troubleshooting addresses missing commands through PATH and shell configuration, permission errors without defaulting to sudo, occupied ports through an alternate port or a verified owned process, and failed database connections through service, connection-string, and credential checks. Setup scripts can automate prerequisite checks, dependency installation, safe environment-file creation, and verification.

Platform examples use Homebrew on macOS, Linux package managers, and Windows installers or package tools. Git, IDE settings, shell files, and npm configuration are included. The Docker example connects an application to PostgreSQL with persistent data. It is for local development: use unique credentials, loopback-bound published ports, and readiness checks because depends_on alone does not establish database readiness. Docker group membership grants root-equivalent host control; rootless Docker may be appropriate.