Parsing the stock exchange notice [1], the three founders seem to have received 42 Million USD. If they had the same amount of shares, they received around 14 Million each.
> The three founders of Memfault - CEO Francois Baldassari, CTO Chris Coleman and VP Developer Experience Tyler Hoffman – will reinvest 30% of their share sale proceeds in Nordic Semiconductor shares, totalling approximately USD 13 million.