When edtech company Preply became a unicorn earlier this year, employees in its Kyiv office celebrated with cake — because that’s what you do, even in the middle of a war. In the four years since Russia’s full-scale invasion of their country, Ukrainian startups have done more than survive: They are still building and growing. Preply, for instance, will use the proceeds of its latest round to hire some 100 engineers across its global teams — including in Ukraine, where one-third of its engineering staff is based. Preply is one example among many. Defense tech has grabbed the most attention , especially for the speed at which innovations reach the battlefield. But the same engineering talent and ingenuity are emerging as common denominators across sectors that also contribute to strengthening Ukraine. With Ukraine facing a far larger attacker, the country takes a dim view of efforts to escape mobilization.…