Sentry Performance Tracing

Overview

Sentry performance monitoring captures distributed traces across your application stack, measuring latency, identifying bottlenecks, and tracking Web Vitals. The v8 SDK uses a span-based API where Sentry.startSpan() replaces the deprecated startTransaction(). Auto-instrumentation covers HTTP, database queries, and framework routes out of the box. Manual spans let you measure business-critical operations. Combined with profiling (profilesSampleRate), you get function-level flamegraphs attached to traces.

Prerequisites

• Sentry SDK v8+ installed (@sentry/node >= 8.0.0 or sentry-sdk >= 2.0.0)
• tracesSampleRate > 0 set in Sentry.init() — performance data is not collected at zero
• Performance monitoring enabled in your Sentry project settings (Settings > Performance)
• For distributed tracing: all participating services must have Sentry SDK initialized

Instructions

Step 1 — Configure Tracing and Profiling in SDK Init

Set tracesSampleRate to control what percentage of requests generate traces. Use tracesSampler for dynamic, per-endpoint sampling. Add profilesSampleRate to attach function-level flamegraphs to sampled transactions.

TypeScript (@sentry/node):