Why is Russia on top of programming contests and what about tech companies?

First of all, there are some tech companies, and some of the are known outside of Russia, such as:

Kaspersky Lab and [nowadays a bit less popular] Dr. Web - are quite famous Russian anti-virus solutions.
Yandex - Russian version of Google with its Search, Maps, Mail, Translate, Taxi (not Uber, but something), Video, Photo, Market aggregator, Money (Paypal rival?), set of business suit (including DNS tools, corp email and other stuff), etc., etc.
Jet Brains - the company which produced well known IDEs like IntelliJ IDEA, PyCharm, PHPStorm, etc.; ReSharper plugin; new programming language - Kotlin, etc. This company is like Apple for programmers. Its tools are costly, but they are much better than the competition, their attention to details is amazing.
ZeptoLab - you know it, “Cut the rope” makers.
MCST - Russian version of Intel and ARM together :)
Nginx - known by geeks
ABBYY - OCR and PDF tools
1C Company - almost all companies in Russia use SW of this company for their book keeping, and a bunch of IT guys get super rich by supporting/writing programs in its custom “1C” programming language.

Those are the most visible ones. If you have never heard of any of them, then you’re either IT-ignorant person or just forgot them. But there are certainly quite a few more IT companies in Russia, which power government website, utilities, B2B sector, retail, B2C, edu, med, military, research, etc., etc. Not that many companies as in the Valley, but at least not a complete vacuum.

Now, why Russians are good at competitions. It’s easy: schools, economy and number of people:

- some schools are really good and they actually have ACM preparations as hobby “out-of-the-class” activities.
- most of other schools are not so good (or, rather, quite bad), so students with some IT knowledge prefer to study on their own to outperform the teachers and show off in front of the class.
- the worse the economy is, the more things people have to repair rather replace/buy new, hence there should be those “tech service providers” or “fixers” who fix you the PC, pirate Windows, help create personal website, etc., etc. So, students are attracted by high demand and quickly learn how to do those things to provide the supply.
- the more people country has, the more technically literate pupils it provides (same happens with China and India, but they have even higher numbers).

And lastly, why there are not that many well-known international Russian IT companies? Mainly because of the long delay Russia had before entering market economy. There are still quite a few people disliking capitalism, or in general being not capable or not ready to start their own business. Just by looking at the number of businesses created in the US vs Russia you may grasp the gap (also consider that not all of those businesses are pure Russian (they may be just Russian branches), and a big amount of companies are short-living tax-evasion cover-companies; so real numbers are even lower in Russia):

But even if Russians are brilliant at IT, and want to open the company - it’s not always possible (they may not have the courage, guts, resources, energy or knowledge to start an IT company).

As an example, look at Qik startup which was created by a Russian brilliant IT guy Nikolay Abkairov, but he wouldn’t have been able to do so without a help for foreign friends who secured funds and business contracts. As a result, headquarters of Qik was located in CA, USA, but main development center was in Zelenograd (Moscow), Russia. In 2011 Skype acquired Qik for $150M and Russian office was disintegrated, and most of developers relocated to Europe or the U.S.

Recently Alibaba acquired Mail.ru, let’s see what will happen with developers.

UPDATE: As correctly pointed out by Ivan, Alibaba + Mail.ru only agreed on a partnership about mobile games, it wasn’t an acquisition. Not all news are trustworthy.