Ruby on Rails Q & A


How to implement multi-tenancy in Rails?

Multi-tenancy is a software architecture pattern that allows multiple customers or “tenants” to use a single instance of an application while ensuring that each tenant’s data remains isolated. This is particularly valuable for SaaS (Software as a Service) applications. In the Rails ecosystem, there are several approaches to implement multi-tenancy:


  1. Schema-Based Multi-Tenancy:


   – In this approach, each tenant gets their own schema within the same database. PostgreSQL, with its support for schemas, is a popular choice for this.

   – The `Apartment` gem facilitates schema-based multi-tenancy. After adding the gem to your Gemfile and running `bundle install`, you can configure it to switch between schemas based on subdomains or domains.


  1. Database-Based Multi-Tenancy:


   – Each tenant gets its own database. This approach might be overkill for small applications, but it provides the highest level of data isolation.

   – The downside is the overhead of managing multiple databases, making backups, and migrations more complex.


  1. Scoped Data Multi-Tenancy:


   – Here, all data resides in the same database and schema. Every table that contains tenant-specific data has a `tenant_id` column (or equivalent), ensuring data isolation at the application level.

   – Implementing this manually requires diligence, ensuring every query scopes data by the current tenant. Frameworks like `ActsAsTenant` gem can make this easier.


  1. Subdomain-Based Tenant Identification:


   – One common pattern is to identify tenants by subdomains. For instance, `` and `` might represent different tenants. This can be achieved using Rails’ routing constraints.


  1. Middleware for Tenant Context:


   – Using middleware ensures that the tenant context is set up early in the request lifecycle and available throughout the application.


When implementing multi-tenancy, consider security implications. Ensure data leakage doesn’t occur between tenants. Testing plays a pivotal role in this, so make sure to have thorough tests covering multi-tenant scenarios. Depending on the nature and scale of your application, choose an approach that aligns with your requirements and infrastructure capabilities.

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Senior Software Engineer with a focus on remote work. Proficient in Ruby on Rails. Expertise spans y6ears in Ruby on Rails development, contributing to B2C financial solutions and data engineering.