Samsonov is a former 2015 first round pick (22nd overall) of the Washington Capitals. After developing in the KHL for a few seasons, Samsonov spent the last three years with the Capitals.
After posting an underwhelming .896 save percentage in 44 games last season, the Capitals decided not to offer Samsonov a qualifying offer. This allowed him to walk into unrestricted free agency, where the Maple Leafs signed him to a one year, $1.8 million dollar contract.
Samsonov is expected to backup Matt Murray this season, and even push for the number one spot. It is still early, of course, but if he continues to play as he did in his debut, don't be surprised if we see a lot more of Samsonov this season.