Standing next to her company's stand, Olga Shapovalova, who works at education technology company Headway, said Russia's invasion on Feb 24 changed everything. Working from a bomb shelter became normal. Some of the startup's employees fled.

But even as Russian missiles rained down, Headway grew its business. It hired dozens of workers, opened an office in neighbouring Poland, and used its learning app to combat the invader's propaganda.

"This is how we show that Ukrainians are so strong and we can get business done," said the 31-year-old. "We are trying to grow - it's how we fight, in our own way, to help Ukraine and our economy."

Alexander Sobolenko, the chief executive of Releaf Paper, which is headquartered in Kyiv and transforms biowaste into sustainable paper, struck a similar chord.