IBM Cloud Kubernetes Service (IKS) is the most suitable platform for managing microservices at scale. It provides built-in orchestration for service discovery (via DNS and services), configuration management (via ConfigMaps and Secrets), and robust networking for inter-service communication. While other services can run applications, IKS is specifically designed to handle the operational complexity of a distributed microservices architecture.

Block Storage is an ideal choice for low-latency, high-throughput workloads like financial transaction processing and logging. It provides persistent, high-performance storage that can be attached to virtual servers with very low latency, similar to a local disk. Cloud Object Storage is optimized for durability and scalability but has higher latency, making it less suitable for this real-time requirement.

In IBM Cloud Code Engine, the concurrency setting defines how many requests a single application instance can process simultaneously. If this number is set too low (e.g., to 1), incoming requests will be queued while the instance is busy waiting for a slow external API response. This queueing can lead to client timeouts, even if the application and API are functionally correct. Adjusting the concurrency limit is a key tuning parameter for I/O-bound applications.

IBM Cloud Direct Link is the service designed for creating a private, dedicated network connection between an on-premises data center and IBM Cloud. It establishes a layer 3 connection that bypasses the public internet, providing consistent, secure, and high-bandwidth network extension. While VPN offers encryption over the public internet, Direct Link provides the true private network extension required for a seamless hybrid model.

IBM Cloud Continuous Delivery (part of the IBM Cloud Toolchain) is a managed service specifically designed for creating automated DevOps pipelines. It integrates natively with Git repositories, can trigger on Git events, includes built-in stages for building container images (using IBM Cloud Container Registry), running scans, and deploying to IBM Cloud Kubernetes Service (IKS) via a Kubernetes deployment job. It provides the integrated, low-overhead orchestration needed for this CI/CD scenario.

For a virtual server instance on IBM Cloud, the most direct action for vertical scaling (increasing CPU/RAM) is to resize the instance to a larger profile. This operation can often be done with a reboot, which is significantly faster than provisioning a new server and manually migrating data. While adding a cache or replica are valid architectural improvements for specific bottlenecks, the question asks for the quickest way to increase the capacity of the *existing* server, which is resizing.

IBM Cloud Internet Services’ Global Load Balancing (GLB) feature is designed for this exact purpose. It uses the CIS global network to perform health checks on your application endpoints in different regions (or clouds). Based on the health status and the user’s geographic location, GLB’s DNS responds with the IP address of the closest healthy endpoint, ensuring high availability and performance.

The most efficient and reliable method is to include the tagging requirement directly in the provisioning command. The IBM Cloud CLI for VPC infrastructure services (like block storage) supports a `–tag` parameter (e.g., `–tag cost-center:prod-123`). This ensures the tag is applied at creation, is consistent, and requires no post-provisioning steps, which is crucial for automation at scale.

IBM Cloud Event Streams, a managed Apache Kafka service, is ideal for event-driven architectures. Cloud Functions can be configured with a trigger that listens to a specific Kafka topic in Event Streams. When a new message (event) arrives on that topic, it automatically invokes the associated serverless function. This provides the desired event-driven, cost-efficient execution model, as the function only runs in response to work.

IBM Cloud Kubernetes Service (IKS) is the most suitable platform for managing microservices at scale. It provides built-in orchestration for service discovery (via DNS and services), configuration management (via ConfigMaps and Secrets), and robust networking for inter-service communication. While other services can run applications, IKS is specifically designed to handle the operational complexity of a distributed microservices architecture.0