If you are looking for Transport Layer Security (TLS) protocol termination ("SSL offload") or per-HTTP/HTTPS request, application-layer processing, review Application Gateway.
Application Gateway is a layer 7 load balancer, which means it works only with web traffic (HTTP, HTTPS, WebSocket, and HTTP/2). It supports capabilities such as SSL termination, cookie-based session affinity, and round robin for load-balancing traffic. Load Balancer load-balances traffic at layer 4 (TCP or UDP).
Reference:
https://docs.microsoft.com/en-us/azure/application-gateway/application-gateway-faq

Azure SQL Database elastic pools are a simple, cost-effective solution for managing and scaling multiple databases that have varying and unpredictable usage demands. The databases in an elastic pool are on a single server and share a set number of resources at a set price. Elastic pools in Azure SQL Database enable SaaS developers to optimize the price performance for a group of databases within a prescribed budget while delivering performance elasticity for each database.
Guaranteed 99.995 percent uptime for SQL Database
Reference:
https://docs.microsoft.com/en-us/azure/azure-sql/database/elastic-pool-overview
https://azure.microsoft.com/en-us/pricing/details/sql-database/elastic/
https://www.azure.cn/en-us/support/sla/virtual-machines/
https://techcommunity.microsoft.com/t5/azure-sql/optimize-price-performance-with-compute-auto-scaling-in-azure/ba-p/966149

(https://docs.microsoft.com/en-us/dotnet/azure/migration/app-service#com-and-com-components) Azure App Service does not allow the registration of COM components on the platform. If your app makes use of any COM components, these need to be rewritten in managed code and deployed with the site or application. https://docs.microsoft.com/en-us/dotnet/azure/migration/app-service
"Azure App Service with Windows Containers If your app cannot be migrated directly to App Service, consider App Service using Windows Containers, which enables usage of the GAC, COM components, MSIs, full access to .NET FX APIs, DirectX, and more."

Reference:
https://azure.microsoft.com/en-us/pricing/tco/
https://azure.microsoft.com/en-us/pricing/hybrid-benefit/
Topic 3, Contoso
Existing Environment
Technical Environment
The on-premises network contains a single Active Directory domain named contoso.com.
Contoso has a single Azure subscription.
Existing Environment: Business Partnerships
Contoso has a business partnership with Fabrikam, Inc. Fabrikam users access some Contoso applications over the internet by using Azure Active Directory (Azure AD) guest accounts.
Requirements: Planned Changes
Contoso plans to deploy two applications named App1 and App2 to Azure.
Requirements: App1
App1 will be a Python web app hosted in Azure App Service that requires a Linux runtime. Users from Contoso and Fabrikam will access App1.
App1 will access several services that require third-party credentials and access strings. The credentials and access strings are stored in Azure Key Vault.
App1 will have six instances: three in the East US Azure region and three in the West Europe Azure region.
App1 has the following data requirements:
Each instance will write data to a data store in the same availability zone as the instance.
Data written by any App1 instance must be visible to all App1 instances.
App1 will only be accessible from the internet. App1 has the following connection requirements:
Connections to App1 must pass through a web application firewall (WAF).
Connections to App1 must be active-active load balanced between instances.
All connections to App1 from North America must be directed to the East US region. All other connections must be directed to the West Europe region.
Every hour, you will run a maintenance task by invoking a PowerShell script that copies files from all the App1 instances. The PowerShell script will run from a central location.
Requirements: App2
App2 will be a NET app hosted in App Service that requires a Windows runtime. App2 has the following file storage requirements:
Save files to an Azure Storage account.
Replicate files to an on-premises location.
Ensure that on-premises clients can read the files over the LAN by using the SMB protocol.
You need to monitor App2 to analyze how long it takes to perform different transactions within the application. The solution must not require changes to the application code.
Application Development Requirements
Application developers will constantly develop new versions of App1 and App2. The development process must meet the following requirements:
A staging instance of a new application version must be deployed to the application host before the new version is used in production.
After testing the new version, the staging version of the application will replace the production version.
The switch to the new application version from staging to production must occur without any downtime of the application.
Identity Requirements
Contoso identifies the following requirements for managing Fabrikam access to resources:
Every month, an account manager at Fabrikam must review which Fabrikam users have access permissions to App1. Accounts that no longer need permissions must be removed as guests.
The solution must minimize development effort.
Security Requirement
All secrets used by Azure services must be stored in Azure Key Vault.
Services that require credentials must have the credentials tied to the service instance. The credentials must NOT be shared between services.