Sentry.io - From error tracking to performance monitoring, developers can see what actually matters, solve quicker, and learn continuously about their applications - from the frontend to the backend.
log4net - log4net is a tool to help the programmer output log statements to a variety of output targets.
Grafana - Data visualization & Monitoring with support for Graphite, InfluxDB, Prometheus, Elasticsearch and many more databases
AWS CloudTrail - AWS CloudTrail is a web service that records AWS API calls for your account and delivers log files to you.
Datadog - See metrics from all of your apps, tools & services in one place with Datadog's cloud monitoring as a service solution. Try it for free.
Logary - Professional logging metrics and analytics for your apps