Hi, when do you think is a good age for kids to start coding?

IMO, it depends on what you want your kid to become. If it intends towards becoming a programmer or on a similar path, then you can start as early as 8-9 years of age. Before that, focus on their math and calculation skills. You can opt for some abacus classes. The more smart your kid is mentally, the faster can he/she grab things. But if that's not the case, then avoid providing computer usage atleast until 7th-8th grade. Computers/mobiles are addictive and keeps kids away from real touch of life, friends and families.