Telegram

Telegram was founded in 2013 by the brothers Pavel and Nikolai Durov, who had earlier built the Russian social network VK. Pavel Durov is CEO and Nikolai developed the MTProto protocol. The company is registered in the British Virgin Islands, and its development team has been based in Dubai since 2017.

It builds the Telegram messenger with chats, channels, groups, bots, calls and mini apps, plus the paid Telegram Premium subscription launched in 2022. Its own FAQ says it has over 1 billion active users, and clients are open source for most platforms.

Telegram does not publish its team size, and Wikipedia lists only 30 employees without a year, so the figure is unreliable. The company does not disclose where it rents offices; its jobs page lists openings such as C/C++ Software Engineer and Site Reliability Engineer, applied for through a Telegram bot.