What are AWS Spot Instances? Guide to lower cloud costs and avoid downtime

AWS Spot Instances offer a cost-effective solution for running workloads by leveraging unused EC2 capacity at discounts of up to 90% compared to On-Demand Instances, but they come with the caveat of potential interruptions with minimal notice. These instances are suitable for flexible, non-critical tasks such as machine learning training, CI/CD pipelines, batch processing, and rendering, where interruptions can be tolerated. However, they are not ideal for stateful applications or critical services that require guaranteed uptime. Platforms like Northflank enhance the usability of Spot Instances by providing automated fallback strategies to On-Demand Instances, ensuring the continuity of workloads without the need for custom failover logic. This capacity management technique allows businesses to optimize cloud costs while maintaining operational reliability, particularly for workloads that can absorb the risk of sudden instance reclamation by providers like AWS, GCP, and Azure.