So you’ve followed SSO with Spring Security in Kotlin and your service nicely redirects users to your SSO provider when needed, giving you details of who they are. You can debug locally and deploy. Nice. 🎉 However, when you increase your number of compute nodes to 2+ then users often…

Neat little trick: allow your web app’s users to passively notice that they can zoom in on a picture by clicking, with no instructions. .magnify { cursor: zoom-in; /* magnifying glass with a + */ transition: transform .25s; /* don't snap */ } .magnify:active { cursor: zoom-out; /* magnifying glass with a - */ transform: scale(2); /* a lot larger */ } You might also want to highlight the temporarily enlarged image by giving it an opaque background and perhaps a border or box-shadow in the .magnify:active rule.

It’s a smally but a goody. I wanted to show a small message in my web app, perfectly centred, with dynamic content. It took me a while to figure it out, reading lots of CSS rules, but the solution is quite simple in the end. The catch is that it’s…

I’m writing an internal productivity tool in which users can change shared data in a database, so therefore I want to authenticate and identify them. It should also be a painless process for users: quick and with no added steps. Getting there wasn’t straightforward and the details will be useful…

I really feel like this podcast episode from researcher Rob Cross (embedded at the bottom) is relevant to my life and to the lives of many people I have worked with. We’re doing more collaborative work than ever before, and the problem is that it’s overloading us. There are times…

I recently resumed (exhumed?) a project that I started waaaaaaay back during the first covid lockdown, to raise it up to minimum viable product status, and that meant adding the ability to take payments for its services. I chose to do that via Stripe. Along the way I learned how…

UUIDs are great for identifying users, requests, transactions, tenants etc etc. They are unlikely to collide, their predictable format reduces cognitive load, rules on their content avoid compatibility issues (ever try putting random strings into URLs and hoping for the best?), their ubiquity means you don’t have to explain them…

This was something that appeared quite mysterious and occasional at first, but seems to have a very simple explanation in the end. (This is a software engineering story.) I had a REST API that very occasionally returned results to the wrong user. Logging confirmed that this never happened inside my…

As the climate heats, climate scientists predict that the effects will not be smoothly spread out over time nor space. It will be lumpy. Some times and some places will see particularly increased temperatures. Apparently, Western Europe is predicted to especially get heatwaves: more than other comparable parts of the northern hemisphere. Temporarily sweltering in unusually high temperatures during the northern summer is going to be usual.