# Cal.com v5.4.19 — Release & Upgrade Intelligence
- **Product:** Cal.com (https://cal.com)
- **Version:** v5.4.19
- **Released:** Jul 11, 2025
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/calcom/updates/v5.4.19/

## Executive Summary (TL;DR)
Cal.com v5.4.19. Source highlight: chore: Add High-Load warning for availability checks with many users

## New Features
- chore: Add High-Load warning for availability checks with many users
- feat: remove unused x-cal-timezone header and middleware matcher
- Revert "feat: add race condition test for calendar-cache-serve booking flow"

## Improvements
- perf: Remove Redundant Key in common.json for english
- refactor: enhance UI spacing and text styling in Locations component …

## Bug Fixes
- fix: use domain errors instead of trpc
- fix: Move pbac to prisma from kysley
- fix: Add new route to create team routing-form response
- fix: Always return `cancellationReason` and `cancelledByEmail` for cancelled bookings
- fix: improve layout in copy times popup by @devin-ai-integration[bot] in https://github.com/calcom/cal.com/pull/22368
- revert: "fix: Add new route to create team routing-form response (#22…