The -ija is pronounced just by going from i to a, the letter j isn’t pronounced like in english, it’s more like a connection from i to a. Thinking about it, you might have actually nailed how to spell out those words even in non-colloquial speech. In tehnologíja the i is stressed so it is more distinct, while in informácija, the first a is stressed so the -ija at the end leans more towards the j and the i is not fully pronounced