When recommending a streaming solution, the architect must evaluate how each event type handles Record-Level Security (Sharing). Change Data Capture (CDC) is unique because it ignores sharing settings for record change events. This means all records of an enabled object generate change events, regardless of whether a particular user has access to those records in the Salesforce UI.
While CDC disregards record-level sharing, it does respect Field-Level Security (FLS). Delivered events only include the fields that the subscribing user is permitted to access. This is a critical consideration for integrations: if a system requires a "Master" view of all record changes across the enterprise (such as a data warehouse sync), CDC is the appropriate tool because it ensures no data is missed due to user-specific sharing constraints.
In contrast, PushTopic Events (Option A) provide a fixed payload based on a SOQL query and do not allow a "custom" payload in the same sense as Platform Events. Platform Events (Option C) are published from Apex or external APIs, but CDC is a platform-native feature that broadcasts automatically when a database record is modified, rather than being "published from Apex" by a developer.

When an enterprise architect identifies infrastructure-level requirements such as caching, queuing, and complex event handling, it signals a need for a dedicated integration layer. Salesforce is an engagement platform, not a dedicated message broker or Enterprise Service Bus (ESB). For complex event handling in a publish/subscribe scenario, the architect should recommend leveraging middleware to act as the central nervous system of the integration landscape.
The middleware provides a robust environment to manage the lifecycle of a message. It can receive a single event from a publisher (like Salesforce via Platform Events) and then route that message to multiple active subscribers. This decoupling ensures that Salesforce doesn't need to manage the connection state or retry logic for every downstream system. Middleware tools are specifically designed to handle "Quality of Service" (QoS) requirements like guaranteed delivery, message sequencing, and dead-letter queuing, which are difficult to manage natively at scale within Salesforce limits.
Option A is incorrect because shifting from Fire-and-Forget to Request-Reply generally decreases performance and scalability due to the synchronous nature of the wait time. Option C is also incorrect; protocol translation (e.g., SOAP to REST) and heavy message transformation are exactly what middleware tools are built for. By performing these tasks in middleware, you conserve Salesforce's Apex CPU limits and maintain a cleaner, more maintainable CRM environment. Therefore, using middleware for routing and event handling is the standard architectural recommendation for a mature enterprise program.

To provide "instant access" and a seamless experience for Community (Experience Cloud) users, the architect must choose an authentication and provisioning strategy that handles user creation on-the-fly. While both SAML and OpenID Connect (OIDC) are viable for SSO, OpenID Connect is the modern standard for consumer-facing "Social" or external identity integrations because it is built on OAuth 2.0.
The critical component for "self-service" is the Registration Handler. When an OpenID Connect Authentication Provider is configured in Salesforce, you must associate it with an Apex class that implements the Auth.RegistrationHandler interface. This handler is executed during the SSO flow if the user does not already exist. It provides the architect with full programmatic control to:
Match the incoming identity to an existing Contact or Account.
Create a new Contact record if one doesn't exist.
Provision a new User record with the correct Profile, Permission Sets, and Locale settings.
Link the User to the correct Account hierarchy, which is vital for Community security models.
Option A suggests Just-in-Time (JIT) provisioning, which is a declarative way to create users. However, JIT is often too rigid for Experience Cloud requirements, as it has limited ability to perform complex data lookups or handle the specific linking of Contacts to Accounts required for external users. Option C is technically mismatched in common Salesforce terminology; while SAML uses JIT, the Registration Handler is the native, specific mechanism designed to work with Authentication Providers (like OIDC). By using B, the company ensures that a subscriber logging in for the first time via the IAM system is instantly and accurately provisioned in Salesforce, eliminating the need for multiple accounts.

For a unified service experience between Salesforce Service Cloud and B2C Commerce (formerly Demandware), Salesforce provides a purpose-built, cross-cloud solution known as the Salesforce B2C Commerce to Service Cloud Connector.
This connector is part of the Salesforce B2C Solution Architecture and is designed to provide "out-of-the-box" synchronization of data between the two platforms. By implementing this connector, service agents gain several high-value capabilities within the Service Console:
Customer Profile Sync: Ensures that customer data (name, address, etc.) is consistent across both systems.
Order History View: Allows agents to see real-time order data from the Commerce system directly within the Case record page.
Order on Behalf Of: Enables agents to place orders for customers without leaving Salesforce.
While you could build a custom integration using the Commerce REST API (Option B) or MuleSoft (Option C), these would require significant development, testing, and maintenance effort. The Salesforce B2C Connector is the recommended "path of least resistance" because it leverages Salesforce's own pre-built logic for cross-cloud interoperability, reducing technical debt and time-to-value. For an architect, choosing the standard1 connector ensures better supportability and future-proofing 2as Salesforce continues to enhance its multi-cloud features.