# Why Rider and ReSharper Were Slow to Start, and How Microsoft Helped Fix the Problem

DevFeed: [Why Rider and ReSharper Were Slow to Start, and How Microsoft Helped Fix the Problem](<https://devfeed.tech/articles/why-rider-and-resharper-were-slow-to-start-and-how-microsoft-helped-fix-the-problem-8801.md>)

Original publisher: [Read original article](<https://blog.jetbrains.com/dotnet/2026/09/09/why-rider-and-resharper-were-slow-to-start-and-how-microsoft-helped-fix-the-problem/>)

Author: Alexander Ulitin

Published: 2026-09-09T16:45:27Z

Content type: article

Language: en

Sources: [The JetBrains Blog](<https://devfeed.tech/sources/the-jetbrains-blog.md>)

Topics: [resharper](<https://devfeed.tech/topics/resharper.md>), [out-of-process](<https://devfeed.tech/topics/out-of-process.md>), [Latency](<https://devfeed.tech/topics/latency.md>), [Microsoft](<https://devfeed.tech/topics/microsoft.md>), [telemetry](<https://devfeed.tech/topics/telemetry.md>)

Tags: [defender](<https://devfeed.tech/tags/defender.md>), [logs](<https://devfeed.tech/tags/logs.md>), [microsoft](<https://devfeed.tech/tags/microsoft.md>), [net-tools](<https://devfeed.tech/tags/net-tools.md>), [oop](<https://devfeed.tech/tags/oop.md>), [out-of-process](<https://devfeed.tech/tags/out-of-process.md>), [performance](<https://devfeed.tech/tags/performance.md>), [resharper](<https://devfeed.tech/tags/resharper.md>), [resharper-oop](<https://devfeed.tech/tags/resharper-oop.md>), [rider](<https://devfeed.tech/tags/rider.md>), [telemetry](<https://devfeed.tech/tags/telemetry.md>)

## AI overview

The article investigates slow ReSharper startup after its out-of-process architecture was introduced. Profiling identified Microsoft Defender scanning as the source of substantial first-launch latency, and describes a repeatable investigation tool built with input from Microsoft.

## Source excerpt

When we launched ReSharper's out-of-process (OOP) architecture, users reported slower startup times for IDEs using ReSharper on Windows. After profiling, the cause surprised us: Microsoft Defender was scanning our process for longer than we expected. This post is about what we found, what we learned working with Microsoft, and a tool we built that allows [...]