Back-end architecture is designed with horizontal scalability in mind. We will use lightweight microservices, which can be scaled up on the fly during times of heavy traffic. To provide a singular API calling endpoint, we will use an Application load balancer, which will also be responsible for delegating network requests across microservices. We will regulate the workload of microservices with the help of Amazon’s Auto scaling groups, which will be hosted in more than one geographical location to prevent system downtime. For database solutions, we will be using Amazon Aurora, which provides the fastest transfer speeds possible for cloud solutions. Using Amazon Aurora also ensures 24/7 availability because there is no single point of failure. The database will be hosted in more than one of Amazon’s availability zones, providing the service's availability in the event of natural disasters or similar circumstances. Amazon Aurora is also horizontally scalable by default.