They are a company during the high-growth phase of their business, with a proven business model where the cost of revenue is less than the revenue gained. See their accounts on the link you posted.
They are a "loss making venture" because they are investing in growth. That's why the cash-at-hand is important - if it's low then one can question if they can cut expenses quickly enough. That's the difference between WeWork (unprofitable, not much cash, unclear what they could cut to make profits) and Amazon 10 years ago (unprofitable, lots of cash, easy to see places to cut to make profits)
Shopify have over 2 years of expenses as cash just sitting there, and they can cut the marketing by 10% at any point and become profitable. That's why investors have confidence in them, and it's why customers can have confidence too.
This isn't a hard balance sheet to read - it's a rapidly growing business with plenty of resources they are investing in growth. That's the same situation Amazon was in for years - "unprofitable" because all their revenue was going into the business.
