Monolith

What is a Monolith in Ruby on Rails?

In a monolithic Rails application, all parts of the system such as user management, business logic, background jobs, and APIs are developed within one Rails project.

These components share the same codebase, database, and deployment pipeline. Changes to any feature are released as part of the same application, rather than as independent services.

This architecture emphasizes simplicity and tight integration, making it easy to build, test, and reason about the application as a whole.

Why is a Monolith Useful?

Monolithic architecture is often the default and preferred choice for many Rails applications, especially in the early and mid stages.

A monolith is useful because it:

• Is easier to develop and understand

• Has a simpler deployment process

• Avoids network overhead between services

• Makes debugging and testing easier

• Allows faster iteration for small to medium teams

Rails is designed to work exceptionally well as a monolith, with strong conventions that keep the codebase organized as it grows.

How a Monolith Works?

In a monolithic Rails app, all parts of the system live together and communicate through direct method calls instead of network requests.

Key characteristics:

• Single codebase – One Rails application repository

• Shared database – All features use the same database

• Unified deployment – The entire app is deployed at once

• Tightly integrated components – Models, controllers, jobs, and services interact directly

Example

Scenario: A Rails e-commerce application.

Features inside one Rails app:

• User authentication

• Product catalog

• Orders and payments

• Admin dashboard

• Background jobs for emails

All of these features exist within the same Rails project and are deployed together as one application.

Where to Use a Monolith?

A monolithic architecture works best when:

• Building MVPs or early-stage products

• Working with small to mid-sized development teams

• Rapid iteration and simplicity are priorities

• Domain complexity is still manageable

• Infrastructure and operational overhead should be minimal

Many successful Rails applications start as monoliths and evolve only when scale or complexity demands it.

In Summary

A monolith in Ruby on Rails is a single, unified application where all components live in one codebase and are deployed together. It offers simplicity, speed, and ease of maintenance, making it an ideal architecture for many Rails applications before more complex approaches are needed.