Salesforce works on a multi-tenant architecture. In Salesforce, multi-tenancy means that many customers or tenants share the same computing resources in Salesforce (infrastructure, database, application services and network).

Each customer’s data is logically isolated for security and integrity but it is stored on the same servers and database.

Key Components of Multi-Tenant Architecture

1. Shared Infrastructure
   • Salesforce operates on a single cloud platform.
   • Customers (tenants) in Salesforce share hardware resources (servers, database storage and network) and the core platform software.
2. Single Code Base
   • All customers use the same version of the Salesforce application.
   • Salesforce provides three update releases per year (Spring, Summer and Winter).
   • Since there’s a single code base, updates take place automatically, with zero downtime, without needing users to intervene.
   • The customizations made by each tenant (apps, triggers, fields, workflows, etc) are preserved because they are stored as metadata.
3. Metadata-driven Architecture
   • The most important component of Salesforce’s multitenancy is the metadata.
   • The application consists of the Code, which is the standard platform and the Metadata, which are the customizations made by the users.
   • Metadata includes :
     • Custom Objects and Fields
     • Page Layouts
     • Validation Rules
     • Apex Classes and Triggers
     • Lightning Components
   • The Salesforce engine interprets the metadata at runtime to give each customer a personalized version of the shared platform.
4. Logical Data Separation
   • Even though every customer’s data is stored in a single relational database, a unique OrgID and tenant identifiers keep their data isolated.
   • Salesforce maintains strict security boundary so that one org is not able to access another org’s data.
   • This ensures privacy, security and integrity of each tenant’s data.
5. SecuritySalesforce implements multi-layered security.
   • Data Isolation: Org-level identifiers separate each tenant’s data.
   • User Authentication and Profiles: Only authorized users in an org can access its data.
   • Field-level and Record-level security: Allows even more intricate access control.
   • Encryption at rest and in transit: Protects sensitive data.
6. Scalability and Performance
   • Customers don’t need to worry about scaling their own servers, Salesforce does it for them.
   • Salesforce performs load balancing and resource pooling to dynamically allocate CPU, memory and storage to meet the demands of the tenants.
7. Cost Efficiency
   • Salesforce uses cloud resources that is shared by multiple tenants, which makes it more cost-effective.
   • Businesses can pay a subscription fee for their share of Salesforce resources instead of buying dedicated servers and resources.

Benefits of Multi-Tenant Architecture

• Cost Efficiency:
  • Since resources are shared, customers don’t need to buy expensive hardware or software.
  • The costs of maintenance, security and upgrades are distributed among all the tenants; hence no single tenant has to pay the full cost.
• Seamless Upgrades:

All tenants use the same code base, so updates take place automatically. Therefore, customers always get to use the latest version without any downtime.

• Scalability:

Salesforce allocates resources (CPU, memory and storage) dynamically according to customer needs. Therefore, customers don’t need to worry about scaling their infrastructure as their business grows.

• Security and Data Isolation:

Each organization’s data remains logically separated and securely isolated even though many organisations share the same infrastructure and database. Tenants can enjoy enterprise-level security without managing it themselves.

• High Reliability and Availability:

Salesforce efficiently handles redundancy, failover and backups. Tenants benefit from 99.9% uptime without running their own data centers. Service interruptions are handled at platform level.

• Customization without Complexity:

Each tenant can extensively customize their orgs (custom objects and fields, workflows, Apex code, Lightning components), which are stored as metadata in Salesforce. This lets companies get a personalized experience even while sharing the platform.

• Better Resource Utilization:

Resources are optimized across thousands of tenants, which facilitates the efficient use of servers, storage and network. This facilitates performance and avoids waste of dedicated servers.

• Faster Innovation: Since tenants use the same code base, Salesforce can deliver new features to all tenants at once.