Raygun - Raygun gives developers meaningful insights into problems affecting their applications. Discover issues - Understand the problem - Fix things faster.

strace - Trace system calls and signals. A diagnostic, debugging and instructional userspace utility.

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.

ftrace - A function tracer for the Linux kernel.

Kafka - Apache Kafka is publish-subscribe messaging rethought as a distributed commit log.

Valgrind - Valgrind is an instrumentation framework for building dynamic analysis tools.