---
title: "Adrien Wald (@mrlowlevel) | Hashnode"
description: "Adrien Wald (@mrlowlevel) writes on Hashnode. Read their latest articles and follow their work."
url: "https://hashnode.com/@mrlowlevel"
---

@mrlowlevel

# Adrien Wald

@mrlowlevel · Joined August 2025

### [React Slots: Dynamic Sidebars and Headers Without the Mess](https://eng.coloop.ai/react-slots-dynamic-sidebars-and-headers-without-the-mess?utm_source=hashnode&utm_medium=feed)

The Problem You have a layout with a sidebar. Different pages need different sidebar content. The obvious solutions all have tradeoffs: Prop drilling: Pass sidebar content up through every layer. Verbose, brittle. Global state: Store sidebar config i...

3 min read · [eng.coloop.ai](https://eng.coloop.ai/react-slots-dynamic-sidebars-and-headers-without-the-mess?utm_source=hashnode&utm_medium=feed)

[Jan 28](https://hashnode.com/posts/react-slots-dynamic-sidebars-and-headers-without-the-mess/697a1a36fac17ac5852ae2c7)

### [State is a Record of the Past, Not a Claim About the Present](https://eng.coloop.ai/state-is-a-record-of-the-past-not-a-claim-about-the-present?utm_source=hashnode&utm_medium=feed)

One of the most common React mistakes I see is using useEffect to keep two pieces of state in sync. It seems intuitive, but it introduces a subtle bug — and more importantly, it reveals a misunderstanding about what state actually represents. The Pro...

3 min read · [eng.coloop.ai](https://eng.coloop.ai/state-is-a-record-of-the-past-not-a-claim-about-the-present?utm_source=hashnode&utm_medium=feed)

[Jan 23](https://hashnode.com/posts/state-is-a-record-of-the-past-not-a-claim-about-the-present/6973d9730995fe230ece9492)