Streaming API is the best option for sending real-time notifications of changes to Salesforce data. Streaming API uses a publish-subscribe model to push relevant data to subscribers without polling. Streaming API supports PushTopic events, whichare based on SOQL queries that define the data changes to listen for. The affiliate company can subscribe to a PushTopic event on the NTO Salesforce org and receive notifications whenever the data that matches the query changes. This way, the affiliate company can be informed of any updates to the opportunities in the NTO Salesforce instance.

The Connect REST API is designed to access Chatter feeds and social data such asusers, groups, followers, and files. By using this API, the integration can query the Chatter posts that include the #thanksNTO hashtag and post them to Twitter using another API. The REST API, Streaming API, and Apex REST are not specific to Chatter and do not provide the same level of functionality and ease ofuse as the Connect REST API2

 Both Platform Events and Outbound Message offer declarative means for asynchronous near-real time needs. They aren’t best suited for real-time integrations (A). In both Platform Events and Outbound Messages, the event messages are retried by and delivered in sequence, and only once. Salesforce ensures there is no duplicate message delivery (B). Message sequence is possible in Outbound Message but not guaranteed with PlatformEvents. Both offer very high reliability. Fault handling and recovery are fully handled by Salesforce ©. Number of concurrent subscribers to Platform Events is capped at 2,000. An Outbound Message configuration can pass only 100 notifications in a single message to a SOAP end point (D). Both Platform Events and Outbound Message are highly scalable. However, unlike Outbound Message, only Platform Events have Event Delivery and Event Publishing limits to be considered (E). Reference: Salesforce Integration Architecture Designer Resource Guide, page 23

Therequirements that the integration architect should evaluate while designing the integration needs of this project are:

Assess security requirements for internal systems and decide Integration methods that support the requirements.

Evaluate the build of acustom authentication mechanism for users in each country and support for customers and partners.

Evaluate Salesforce native authentication mechanism for all users including customers and partners.

The integration architect should assess the security requirements for internal systems, such as the ERP system and other systems that will be integrated with Salesforce for Sales and Support business processes. The security requirements may include authentication protocols, encryption standards, data access policies, and compliance regulations. The integration architect should then decide on the integration methods that support these requirements, such as SOAP or REST APIs, middleware solutions, or connectors. The integration architect should also evaluate the build of a custom authentication mechanism for users in each country and support for customers and partners. A custom authentication mechanism may be necessary to integrate with the local active directory of each country and provide a seamless user experience. The integration architect should also consider how to support customers and partners who have different authentication options, such as self-registration or Google login. The integration architect should also evaluate Salesforce native authentication mechanism for all users including customers and partners. Salesforce native authentication mechanism is a built-in feature that allows users to log in to Salesforce with their username and password. Salesforce native authentication mechanism may be simpler and easier to implement than a custom or third-party solution, but it may not meet all the security requirements or user preferences. The integration architect should compare the pros and cons of each option and choose the best one for the project. Evaluating Salesforce solution for customers and for partners, using third party solution for internal users is not a valid requirement because it does not address the need to authenticate internal users with their local active directory. Considering third party Single Sign On solution supporting all user authentication including customer and partner is not a valid requirement because it does not address the need to integrate with internal systems and their security requirements.

SObject Collections is a REST API composite resource that allows you to create, update, or delete up to 200 records in one API call. You can specify the type of operation (create, update, or delete) for eachrecord in the request body, andthe response body will contain the status and IDs of each record. SObject Collections is suitable for bulk operations on records that are not related to each other1.

SObject Tree is another REST API composite resource that allows you to create up to 200 records in one API call. However, unlike SObject Collections, SObject Tree requires the records to be related to each other in a hierarchy. You can specify the parent and child records in a JSON tree structure, and the response body will contain the reference IDs and URLs of each record. SObject Tree is suitable forcreating nesteddata in one request2.

Batch is a REST API composite resource that allows you to combine up to 25 requests in one API call. Each request can be a different type of operation (query, create, update, delete, etc.) on different objects. The response body will contain the status and results of each request. Batch is suitable for grouping multiple requests into one transaction3.

Composite is a REST API composite resource that allows you to execute aseries of REST API requests in one API call. You can use the output of one request as the input of another request using a reference ID. The response body will contain the status and results of each request. Composite is suitable for chaining requests that depend on each other.

Therefore, the correct answer is A, because SObject Collections is the only REST API composite resource that allows bulk updates on records that are not related to each other.

Using middleware queuing and buffering is a solution that can handle errors during service outages by storing the messages in a queue until the service is available again. This way, Salesforce does not loseany data or encounter any failures when the service is down. Using @future jobld and custom scheduled apex process to retry failed service calls is not a good solution because it can consume a lot of governor limits and create a lot of duplicate records. Using Outbound Messaging to automatically retry failed service calls is also not a good solution because it has a limited number of retries and a fixed retry interval, which may not be sufficient for long service outages. Using Platform Event replayld and custom scheduled Apex process to retrieve missed events is not applicable for this scenario because Platform Events are used for event-driven integration, not for web-service integration. Reference: Salesforce Integration Architecture Designer Resource Guide, page 29-30

The recommendations that the Salesforce integration architect should make to fulfill the requirements around caching, queuing, error handling, alerts, retries, event handling, etc. arebased on the best practices and capabilities of the middleware tools. The recommendation B is valid because middleware tools can provide true message queueing for integration scenarios that require asynchronous processing, guaranteed delivery, load balancing, etc. The recommendation D is valid because middleware tools can handle various events that may occur during the integration process, such as logging errors, sending notifications, triggering recovery actions, etc. The recommendation E is valid becausemiddleware tools can support the publish/subscribe pattern for event-driven integration, where the middleware can route messages from publishers to subscribers based on topics or filters. The recommendation A is not valid because transforming a fire-and-forget mechanism to request-reply does not improve performance, but rather increases the latency and complexity of the integration. The recommendation C is not valid because message transformation and protocol translation are tasks that are better suited for middleware tools than Salesforce, as they can handle different formats and protocols more efficiently and flexibly23

1: Integration Architecture Designer Resource Guide 2: Integration Patterns and Practices 3: Salesforce Integration Architecture Designer Certification Exam Guide