Why's that company so big? I could do that in a weekend
I often hear this logic from inexperienced engineers. 
My answer to them is: Then why don&#x27;t you do it? &lt;grin&gt;<p>Recently a junior engineer said this to me about Uber, and I helped him to understand - His logic was &quot;it&#x27;s just a taxi app&quot;.<p>There were loads of Taxi apps before Uber and loads of them after Uber. Yet none of them were uber?<p>Sure that a medium complexity CRUD app can do the pickup and scheduling, and spit out some json to the app.<p>But what if you have 100,000 journeys taking place simultaneously, and you must track their positions so that you can render the journey map on the invoice?<p>Can you do live traffic planning and re-route around the busy traffic on the fly?<p>Does your weekend include the full billing system? This is a mandatory requirement for a business.<p>Can you spot busy periods and increase the fares according to the laws of supply and demand? All online in realtime? Can you continuously A&#x2F;B test this to optimise profits?<p>Can you deal with the fact that maps and roads are always changing?<p>All of these and more are the things that make Uber, Uber, otherwise you&#x27;re just one of those shitty taxi apps that failed.<p>Still think you can build it in a weekend?