Most web design advice is written for people on fibre in a quiet office. Your customers are on a phone, on mobile data, possibly during an outage, with the battery at 12%. Designing for those conditions is not a compromise. It makes the site better for everyone.

Design for the worst connection, not the best

A heavy page on fibre feels fine, which is exactly why heavy pages survive. Build with a data budget instead: aim for a page that weighs under a megabyte in total. That rules out enormous hero videos and twenty uncompressed photos, and it forces the useful decisions.

Data costs money here. A visitor who burns 8MB loading your home page has paid to read it, whether or not they consciously notice.

Put the important thing first in the code

On a slow connection, pages arrive in pieces. What loads first should be your name, what you do, and how to reach you. Sliders, animations and embedded maps can arrive later or not at all; the page must still work if they never do.

Outages change the browsing pattern

During an outage people switch to mobile data, tower load goes up, and speeds drop for everyone in the area. It is also when many home-office workers do their admin and start looking for suppliers. In other words, your site gets a spike in traffic exactly when conditions are worst.

It also affects you, not only visitors. If your site runs on a server in Johannesburg with proper backup power and your email lives with the same host, an outage at your house does not take the business offline.

Practical rules I build by

• Compress every image and serve WebP
• One or two font families, never four
• Click-to-call and WhatsApp buttons always visible on mobile
• Text that is readable in daylight, with real contrast, not grey on grey
• Tap targets big enough for a thumb
• Forms short enough to finish on a bad connection, with a WhatsApp fallback if the send fails
• Local hosting so the round trip is short

The side effect

Everything on that list also improves your Core Web Vitals, which Google uses as a ranking signal. Building for the customer standing in a parking lot with one bar happens to be the same work as building for search.