Complex sentence: James took the position as an interim measure whilst a permanent candidate was looked for, he ended up staying with "The Next Generation" as lead production designer for the rest of the series, and afterwards joined' in the same role.
Split into simpler sentences: James took the position as an interim measure while a permanent candidate was looked for. He ended up staying with "The Next Generation" as lead production designer for the rest of the series, and afterwards joined' in the same role.