Designing websites has never been as difficult as it is at the moment, and it’s only going to get harder.

Think about this for a moment – people born since about the year 2000 are unlikely to have ever walked into a travel agent or mobile phone shop. They’re unlikely to have been inside a bank more than a couple of times in their lives. Couple this with more than 10% of the UK still haven’t used the Internet.

In Q2 2013, AOL earned a staggering $166m from dial up modems. It’s fair to take a decent chunk of that revenue and claim it’s from ‘forgotten direct debits’ (now here’s an irony: a quick search for forgotten direct debits produces some interesting reading from AOL which claims over 2.5m Britons are paying for services they no longer need!).

So we have this strange anomaly where the Internet is being used by teenagers who have grown up using web browsers before they could read and over 75 year olds who are just starting to use the Internet for the first time.

And then they’re the range of screens: from a small Blackberry screen to iOS and Android (my S4 feels closer in size to an iPad Mini than an iPhone) to tablets. These screens demand large contact areas for fingers to select rather than small target areas easy to access with a mouse. Then on to desktops, which have a wider array of sizes than ever before. At work I use a square monitor with a relatively small resolution but when I work from home I have a large widescreen monitor where some sites look really nice and some look like a size zero.

Responsive design isn’t always the answer. I spend time battling against the marketing wave which convinces clients into believing every website needs to be responsive, to fit large and small browsers, touchscreen and mouse driven.

But responsive isn’t the only option. Fire up the BBC website on a smartphone and you’ll see the mobile site which is a quicker and easier to use than a responsive design. And it really comes into its own when you have a weak signal and want the latest cricket or football scores. A responsive design would be slower to download and use than the excellent mobile site. For high traffic websites it also reduces the cost of bandwidth delivery.

As well as fighting the responsive design marketing wave, I’m also swimming against the tide with mobile first initiatives. Yes mobile is increasing, however there are still very significant numbers of users using desktops. And what happens when wearable technology takes off? Or if TV apps really become mainstream?

The answer to many of these questions is to make sure that any digital platform has a complete API to support all these output devices. This can help multiple teams develop user interfaces in parallel. It also helps store the ‘state’ where users switch devices.

The best in class example of this is Facebook. Open the Facebook app on your phone and you’ll see the number of notifications in your activity feed. Click on some of them. Then look at Facebook on a desktop and you’ll see the new number of notifications. It’s the way it should be, but still so many sites struggle with these concepts.

So while it’s currently the hardest it’s ever been to design user interfaces, there are some great examples out there of how to do this properly, just don’t get too sucked into all the marketing hype.