Update 2 result: Have gone through one sprint with the mentioned actions, the results have significantly improved. Having engaged Tom with more frequent short design discussions ensure that he is bought into and undestand the reasons for certain requirements. This together with more detailed acceptance criteria helped to reduce deviations / better focus of Tom's work to improve delivery. The new problem that we identified through the meeting is that Tom is very insistent on designing the software in his way (at the Business requirements level), so he somehow becomes the 'product owner', sidelining the real BA/PO.
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