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Full Software as a Service (SaaS) entry
How-to guide

Evaluate a SaaS vendor as a buyer

Use the standard SaaS evaluation playbook to compare two vendors on security, scalability, customization, integration, and total cost of ownership.

By Dipojjal Chakrabarti · Founder & Editor, Salesforce DictionaryLast updated May 26, 2026

Use the standard SaaS evaluation playbook to compare two vendors on security, scalability, customization, integration, and total cost of ownership.

  1. Confirm tenancy model and isolation

    Ask the vendor whether the platform is multi-tenant, single-tenant, or hybrid. Request the architecture diagram showing how customer data is logically separated. Confirm encryption at rest and in transit.

  2. Review security and compliance certifications

    Request SOC 2 Type II, ISO 27001, HIPAA, FedRAMP, GDPR, CCPA, and any industry-specific certifications relevant to your business. Review the latest audit report.

  3. Test the customization model

    Stand up a trial or sandbox. Customize a custom object, a custom field, a workflow, and a report. Confirm the customization persists across upgrades and that you do not modify any vendor code.

  4. Validate API and integration capability

    Pull the vendor REST and SOAP API docs. Confirm the endpoints you need (CRUD on every object, bulk operations, webhooks, OAuth 2.0). Test rate limits with a realistic load.

  5. Model total cost over five years

    Project license growth, storage growth, API call growth, integration costs, and professional services. Compare to the equivalent on-prem build cost across the same horizon.

  6. Plan the exit

    Confirm data export tooling. Request a sample export of every object you will store. Verify the export format is parseable and complete. A SaaS contract without a clean exit is a lock-in trap.

Key options
SaaSremember

Vendor-hosted finished application. Customer accesses via browser and API.

PaaSremember

Vendor-hosted runtime for customer-built apps. Salesforce Platform, Heroku.

IaaSremember

Vendor-hosted compute, storage, and network. AWS EC2, Azure VMs.

On-Prem / Self-Hostedremember

Customer installs and operates the software in their own data center.

Gotchas
  • SaaS upgrades are mandatory. Customers cannot pin to an old version. Plan a release-readiness program to validate each new release against your critical flows.
  • Data residency varies by SaaS region. A US-hosted SaaS contract may not satisfy EU residency rules; confirm the data center geography in writing before signing.
  • API rate limits and storage tiers are part of the entitlement. Heavy integration use can push you into a higher tier mid-contract; model usage growth into the budget.
  • Exiting a SaaS contract requires data export and reintegration somewhere else. Negotiate clean export tooling and historical retention before the renewal conversation.

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