Here's the test I run on every product I build. It isn't a user research methodology. It isn't a framework with an acronym. It's a single question: would I use this on a Sunday?
Not a Monday, when I'm in work mode and willing to engage with tools because they're productive. Not a Wednesday, when the week has momentum and I'm clicking through things out of habit. A Sunday. When my son has been fed and the house is reasonably tidy and there's nothing I have to do and I'm sitting on the sofa with my phone in one hand and a hot chocolate in the other. In that moment - the laziest, most voluntary moment of my week - would I open this product? Would I choose to spend my leisure time with it?
If the answer is no, the product isn't good enough.
Why Sunday matters
Sunday is the purest test of personal utility because Sunday is when obligation disappears. During the week, we use products because we need to. We check email because work requires it. We open spreadsheets because deadlines demand it. We use tools because they're tools and tools exist to serve a function that someone else has decided is necessary. Sunday strips all of that away. On Sunday, the only reason you use anything is because you want to.
This distinction - need versus want - is the most important distinction in product building, and it's the one most builders ignore. Most products are built around need. They solve a problem that exists during working hours, in professional contexts, under conditions of obligation. And there's nothing wrong with that. Those products are valuable. But they aren't the products I'm building.
I'm building products that have to earn their place in someone's leisure time. Products that compete not with other software but with watching football, reading a book, going for a walk, or doing absolutely nothing. That's the hardest competition in the world. And it's the only competition that matters for the kind of products I want to make.
Which products pass
Let me be honest about which of my own products pass the Sunday test and which don't. CultureTerminal passes. On a lazy Sunday, I'll open it and scroll through what's happening in culture, advertising, and design. It's the equivalent of browsing a magazine - a pleasant, unhurried way to stay connected to the things I care about. The fact that I built it and still want to use it on Sunday tells me something important about the product.
The London Pub Guide passes, but only conditionally. I use it on a Sunday when I'm planning where to go for a drink. It serves a specific Sunday purpose - the "where shall we go?" conversation that happens in millions of London households every weekend. It doesn't demand my attention unprompted, but when the moment arrives, it's the first thing I reach for. That's a different kind of Sunday pass, but it still counts.
First Out doesn't pass the Sunday test, and it doesn't need to. Nobody uses a tube exit guide on a Sunday. It's a weekday product that solves a weekday problem. That is fine. Not every product needs to pass the Sunday test. But knowing which products are Sunday products and which are Tuesday products helps you understand what you're really building and who you are really building it for.
The difference between tolerate and love
Most software is tolerated. Think about how many apps you have on your phone that you use regularly but wouldn't miss if they disappeared. The ones you use because they're the default, or because switching would be annoying, or because your company requires it. You don't love those products. You tolerate them. And the moment something better comes along, you'll leave without looking back.
Sunday products are loved. They earn their place through genuine value in moments of genuine choice. Instagram is a Sunday product for a lot of people - whatever you think of it, people voluntarily open it in their leisure time because they want to see what is there. Spotify is a Sunday product. A really good game is a Sunday product. The best newsletters are Sunday products - people look forward to them arriving.
The Sunday test isn't really about Sundays. It's about building products that people choose rather than products people settle for. Products that add something to your life rather than products that manage something in your life. Products that make you feel something - curiosity, delight, satisfaction, inspiration - rather than products that help you complete a task.
How to design for Sunday
Designing for Sunday is different from designing for Monday. Monday design is about efficiency - how quickly can the user accomplish their task and get back to work? Sunday design is about enjoyment - how pleasant is the experience of being here? Monday design removes friction. Sunday design adds texture.
This is why the design of my products matters so much to me. If CultureTerminal looked like a corporate dashboard, nobody would open it on a Sunday. The visual experience of using it - the typography, the layout, the colour palette, the way information is presented - isn't decoration. It is the product. The aesthetic is what makes it a Sunday product rather than a Monday one.
Think about the difference between reading the news on a corporate intranet and reading it in a beautifully designed magazine. The information might be identical. The experience is completely different. The magazine invites you to linger. The intranet invites you to finish and leave. Sunday products are magazines, not intranets.
Your own bar
The Sunday test is ultimately a test of honesty. It asks: have you built something you actually enjoy, or have you built something you're proud of having built? Those are different things. I can be proud of a product that solves a problem cleverly without actually enjoying the experience of using it. Pride is about the building. Enjoyment is about the using. And the using is what matters to the person on the other end.
I apply this test ruthlessly, and sometimes the answer is uncomfortable. Sometimes I have to admit that a product I spent weeks building doesn't pass. That it's technically sound, strategically smart, and aesthetically decent, but it isn't something I would reach for on a lazy Sunday afternoon. When that happens, I either make it better or I accept what it's - a useful tool rather than a beloved product. Both have value. But I know which one I would rather build.
So here's my challenge, to myself and to anyone else building things: forget the metrics for a moment. Forget the strategy. Forget the market opportunity. Just ask yourself, honestly, with your Sunday hat on and your hot chocolate in hand - would you use this? Would you choose this over the sofa and a good book?
If the answer is yes, you've built something worth building. If the answer is no, you know what needs to change.
