# The Illusion of Perfect LLM Code

DevFeed: [The Illusion of Perfect LLM Code](<https://devfeed.tech/articles/the-illusion-of-perfect-llm-code-27461.md>)

Original publisher: [Read original article](<https://ariya.io/2026/05/the-illusion-of-perfect-llm-code/>)

Published: 2026-06-01T00:59:21Z

Content type: opinion

Language: en

Sources: [Ariya Hidayat](<https://devfeed.tech/sources/ariya-hidayat.md>)

Topics: [Large Language Model](<https://devfeed.tech/topics/llm.md>), [Security](<https://devfeed.tech/topics/security.md>), [Web app](<https://devfeed.tech/topics/webapp.md>), [Authentication](<https://devfeed.tech/topics/authentication.md>), [Testing](<https://devfeed.tech/topics/testing.md>)

Tags: [authentication](<https://devfeed.tech/tags/authentication.md>), [developers](<https://devfeed.tech/tags/developers.md>), [llm](<https://devfeed.tech/tags/llm.md>), [security](<https://devfeed.tech/tags/security.md>), [testing](<https://devfeed.tech/tags/testing.md>), [vulnerabilities](<https://devfeed.tech/tags/vulnerabilities.md>), [web-app](<https://devfeed.tech/tags/web-app.md>)

## AI overview

The author compares several LLMs on implementing authentication for a web app and finds that they generally follow structured instructions well, while their ability to identify security flaws varies. The article argues that developers should independently review LLM-generated code and test its security before production deployment.

## Source excerpt

I recently tested several different LLMs by tasking them with implementing a simple authentication feature for a web app. It is clear that almost all modern LLMs are now excellent at following a structured blueprint. However, the real differences appeared when looking under the hood at the security of the generated code.