He was selected for the Scotland football team (represented by North Lanarkshire school pupils) at the 2014 International Children's Games alongside Well colleague David Turnbull,[2] who had already been a teammate for several years during their youth careers.

[3] On 27 April 2016, Hastie was part of the Motherwell team that won the Scottish Youth Cup, beating Heart of Midlothian 5–2.

[8] On his first league start for Motherwell on 23 January 2019, with a "slick move", Hastie provided David Turnbull with an assist for the only goal of a win over Hibernian.

[12] As his good form drew increasing attention from supporters and the media, he commented that he was an admirer of Gareth Bale and had been studying the Welsh player's moves to improve his game.

[13] In March 2019 he won the Scottish Premiership Player of the Month award for February, and was linked with a transfer to a bigger club.

[14] Hastie was nominated for the 2018–19 PFA Scotland Young Player of the Year, along with David Turnbull; the award was won by Ryan Kent.