&gt;<i>There are not 10,000 other WhatsApps, FWIW</i><p>No 10,000 other WhatsApps. 10,000 success stories of programs doing what they need to do with a small team behind them and reliability.<p>It&#x27;s about the technical&#x2F;project success aspects, not about the monetary side of the equation -- not even about user count. After all Yahoo (back in the day) and Facebook had a much higher user count while being written in PHP.