Sentry

Sentry is a software company that builds application monitoring tools, describing its product as considered "not bad" by millions of developers. Its platform combines error tracking with performance monitoring, helping developers diagnose, fix and optimize the performance of their code. Application monitoring tools of this kind sit in the observability category, where engineering teams instrument their software so that crashes, slowdowns and failed requests surface quickly after code reaches production.

Sentry connects errors, logs, replays, spans, profiles and metrics through a shared trace, and it is installed by adding an SDK rather than running separate agents. Sentry supports more than 100 programming languages and integrates with tools such as GitHub, Slack, Jira and Linear, as well as coding agents through an MCP server. The product line also includes Seer, an AI debugging agent and code reviewer that uses logs, commits, traces and stack traces to find root causes, along with agent tracing for monitoring the output, tool calls and spend of AI agents. Taken together, these features extend the product beyond classic crash reporting toward teams that build software with or around AI tools.

Sentry counts 200K organizations across 146 countries among its users, and its customers include Disney, Atlassian, Microsoft, Instacart and Anthropic. Sentry began as an open-source project created by its founders to fix their own mistakes, and it has grown to more than 200 employees, with offices in San Francisco, Vienna and Toronto. Its open-source roots fit a pattern common among developer tools, which are often adopted bottom-up by engineers before spreading across an organization.