Sintering of supported cobalt catalysts is an important deactivation mechanism at play during realistic Fischer-Tropsch synthesis conditions. The traditional ways of studying the mechanism of sintering by looking at cobalt particle size distributions derived from transmission electron microscope images on porous supported catalysts, does have its drawbacks. In this mini-review, we show collaborative work between Sasol and its academic partners at the University of Cape Town and Eindhoven University of Technology, in which a two-pronged approach was used to study the topic of sintering. This included the use of model systems (model catalysts and theory) as well as in-situ monitoring of real (industrial) systems for understanding this practical problem in industry. We also show with new data, that the understanding generated, can be used in the mitigation of sintering by using either process conditions, catalyst design or catalyst regeneration.