32. Mark Holt

Holt has overseen significant changes since joining Trainline in 2014, including a massive migration to AWS from its former on-prem infrastructure.

His technology background is extensive, with positions at FT.com, Avis Europe and CPA Global to his name.

Holt's next step is to go for peoples' pockets - or more accurately, their mobiles, with continued development of the Trainline mobile app.