Prior to entering academia, Joost worked for independent video games developer Two Tribes as strategic manager. Joost aided the firm in its transition from a work-for-hire boxed games developer to an independent digital publishing firm. To do so, the team set up a separate publishing entity for which Joost wrote the business plan and helped raise substantive working capital. Joost furtther helped bringing to market several games and has been involved in partnerships with Electronic Arts and Chillingo among others.

When Joost moved to London in 2010, he founded Strategy Guide, an industry analysis and consultancy outfit dedicated to the video games industry. Former clients include international digital production agency Media Monks, advergaming studio Sticky Game Studios, and the United Kingdom trade association for Interactive Entertainment (Ukie). Industry coverage included renowne trade publications Emerce, Gaming Business Review, and Gamasutra. Joost has given invited presentations at various practitioner shows including Digital Shoreditch (London, UK), Festival of Games (Utrecht, NL) and Game in the City (Amersfoort, NL). Most recently, Joost wrote a series of short articles introducing the members of the international pets industry to video games for PETS International. See the blog for some recent articles.

To this date, Joost keeps close ties with the industry. In 2014, Joost gave invited presentations at the Entertainment Software Association (ESA) and published a whitepaper based on his academic research on business models in collaboration with SuperData Research. Joost also played an active role at the 6th Annual Games and Learning Summit at the 2015 Electronic Entertainment Exposition (E3) in Los Angeles (CA).