Back in my happy days in Al-Khobar the only reliable way of being sure you had found the right address was the Domino's Pizza sticker (complete with unique number) at the entrance.
In a more remote part of the Kingdom, another deliver guy told me that they used the water meter number! There's always a way.
Meanwhile, when I came back to Blighty some years ago, and the "dot.com" boom had happened during my lengthy absence, I realised straight away that reliable (secure)
delivery of stuff bought on line was were the money was to be made. Pity that I never found anyone else willing to have a go.

But, there again, I guess that market is already pretty well sewn up by the various courier companies whose massive vans can be seen
Sprinting by everywhere you go. Not to mention the home delivery vans of the all the leading supermarket chains. Now
there's a business model that would do well in Jeddah and Riyadh!

Things are a bit more organised in the UK, of course, with the house number, Post Code, and a Sat-Nav being all you really need.
But (back to deliveries) I'm told that in other parts of the world (
eg, the US) folk have secure containers (the size of industrial garbage bins) where deliveries can be left when no-one is at home. There's another business opportunity, then. Just as long as the thing didn't end up getting confused withe the
Biffa* bin (or vice versa).

The Bottom Line here is:- if you want to make money, stick to everyday things that the population in general need. The basics, like food for example. Or even car mechanics. In the UK, property maintenance and its associates ("garden services") always seems in demand. Forget all about
esoteric stuff like biomedical engineering.
In fact, it may not be wise for a young person in UK to consider engineering at all. Certainly not manufacturing, anyway. Britain's so-called "economy" (now, there's a laugh) has been "service based" for many years. I know blokes around here who make their money exercising (other people's) dogs! Twenty-odd years ago I had the chance to buy a grass-cutting round for £ 4,000. I wish now that I had gone for it!
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Other private waste disposal companies may be available!