Archives 2026/10

Our platform team provides services underpinning the work of something in the order of 1,000 people spread across different roles - developers, architects, support engineers and so on. Each month, there are hundreds of thousands of interactions with our tools - almost all of which are automated through CI. As the Product Lead, I am often asked how i know what to prioritise next in delivery and the answer is simple - we measure Developer Happiness. now don’t get me wrong, i want our developers to be happy, but it’s not that i specifically care about developer happiness in itself. happy developers are great, but in this case what i’m looking for is things that are annoying them - i’m using Developer Happiness as a proxy for all the things which we’re not measuring (or simply can’t measure) but which annoy the teams on the ground as they try to get their job done.

I’m sure we’ve all been there - coat on, shoes on, just about to lock the door and - “did i leave the back window open?”

I wanted something which shows me, at a glance, which windows are open, or confirms they’re all closed.

goals

• low maintenance - dont need to charge it every week
• automatically updates in a few seconds
• our windows can be “closed” or “latched closed” (with a ventilation space around), so support both
• easy to glance at - no complex dashboards
• small and unobtrusive.

What i used

• Home Assistant Yellow
• SNZB-04P/PR1 sensors
• 2.6" Hanshow Polaris Pro 280 Electronic Shelf Label
• LilyGo T-Panel S3
• OpenEPaperLink HA integration

Window sensors

I wanted sensors with long battery life. I have a Home Assistant Yellow at home, which has Zigbee support. I already have several Zigbee plugs around the house. Most permanently powered Zigbee devices act as “routers” so there’s a strong network around the house. I decided to buy Sonoff SNZB-04P: