Datadog is a modern cloud-based SaaS solution that provides real-time monitoring and analytics for DevOps teams. It offers features such as infrastructure monitoring, application performance monitoring, real-user monitoring, network performance monitoring, synthetic monitoring, and alert management. Datadog's key features include its simplicity, excellent support, rich reporting and monitoring capabilities, and scalability. However, it has a host-based pricing structure and limited agentless mode. On the other hand, Splunk is an observability and security platform that provides log management, IT operations, and security analytics. It offers features such as application performance monitoring, infrastructure monitoring, real-user monitoring, synthetic monitoring, security information and event management, on-call, and Splunk Log Observer. Splunk's key features include its extensive data collection capabilities, powerful search features, customizable alerts, and scalability. However, it has a cost-based pricing structure and a steep learning curve. While both tools offer similar features, they cater to different use cases and target audiences, with Datadog focusing on cloud-native environments and Splunk targeting larger enterprises. Other alternatives worth considering include Dynatrace, Sumo Logic, New Relic, Graylog, and the Elastic Stack (ELK Stack). Spacelift is a platform that enables powerful CI/CD workflows for OpenTofu, Terraform, Pulumi, Kubernetes, and more, including integrations with Datadog.