R and Shiny Consultancy

You might have seen The Shiny Side of LLMs pop up on the Shiny blog, which is my latest three-part blog series written for anyone who wants to understand what large language models (LLMs) actually do, and how to use them in a Shiny app. It’s a complete (mini?) guide on how to work with LLMs in both Python and R. Why I wrote this series Before we jump into the summaries, here’s a bit of background on why I wrote it. When I started exploring LLMs, I found the online explanations either too high level or way too complicated. Often they were full of mysterious jargon and missing the “why”. As I wrote on LinkedIn: I don’t like things to be boring or overly complicated. And in the fast-moving world of LLMs it’s easy to get lost in all the mysterious jargon. I prefer plain English, a bit of

Select inputs, aka dropdowns or pickers, show up on nearly every web page or app, but their default look is pretty… basic. Or to put it differently: it’s sometimes even downright ugly. That’s because browsers handle most of their styling, using the system’s native styles, which makes customization tricky. Your normal CSS styling becomes pretty much useless. The usual fix is turning to JavaScript libraries like selectize.js, which Shiny also uses by default. It makes select inputs look nice again! But wouldn’t it be nice if you can also style select inputs entirely with CSS? With Chrome 135 (April 2025), you finally can. A feature that has been long awaited! Styling icons, checkmarks, dropdown lists: all possible. You just need to know which properties you can style. In this article, I’ll walk you through how to switch off selectize.js in Shiny and start taking advantage of this new customizable select

Shiny’s reactive system has a few key players, and one of them is observers. The idea is pretty straightforward: whenever there’s a change in a reactive value or input, you want to do something. Shiny observers make that happen. But there’s more than meets the eye: observers have their little secrets! Before we can uncover any secrets, it’s good to take a step back first and focus on what observers actually are. Which functions are we talking about, and what characteristics do Shiny observers have? After that, it’s time to get into Shiny’s Source Code to see how observers actually work under the hood. What hidden methods exist, and how can you use them in your next Shiny app? All that (and more) in this edition of “Shiny Source Code Explained”!  Table of Contents Observers: what do they do? Observers, such as observe(), observeEvent(), and the more recent combination with bindEvent(),