[1][3] She later studied computer science at Curtin University for one semester, before dropping out after she found the course content outdated.

[4] In 2014, Johnstone and Roy Sugarman founded Transhuman Inc., a mental health and emotion AI technology company.

[5] Johnstone's work saw Transhuman awarded second place in the Top Startups in Delaware list by The Tech Tribune in 2019.

[6] One of Transhuman's technologies with which Johnstone has been involved in is "Be A Looper", a free mental health daily check-in app available in 87 countries.

[13][14] Johnstone has been recognised in a number of business and technology awards and publications, including: Johnstone has been featured by Time,[1] Thrive Global, 2GB,[7] France 24,[2] The Tech Tribune,[6] Anthill, Veja[18] The Examiner,[19][3] The CEO Magazine,[5] Billboard, The Irish News,[20] Opovo, The Daily Telegraph,[21] Radar Amazonico,[22] Stigma Podcast,[23] Cosmopolitan, Startup Daily,[10] The Online Mom,[24] Menzies Law,[25] Singularity University,[12] Fala, The Modern Woman Podcast,[4] Belfast Telegraph, Gazeta de Buenos Ayres,[26] The Farmer,[27] Momentum,[28] IWeek,[29] ICworld, Yahoo!