1, CS: Go uses the source code engine developed by Valve, which is a very popular and highly customized game engine for developing various Valve games.
2. The Road to Survival 2 was developed by Valve's development studio TurtleRockStudios, using another engine of Valve, namely the improved version of the Source engine, which is commonly known as the Source2 engine. So csgo and Road to Survival 2 are not an engine.