The utilisation of engineered therapeutic proteins for basic research, clinical diagnostics, and therapy continues to expand. Consequently, the efficient expression and production of these valuable biomolecules face challenges in improving their quantity and quality while minimizing time and cost. To meet these demands, an increasing variety of recombinant production platforms called cell factories are being developed. Unfortunately, there is no universal production system which can guarantee high yields, particularly as every protein itself causes its own issues in terms of expression and production. Through case studies, the Optimising Expression Platforms conference offers comparisons, evaluations, and solutions that enable protein expression researchers to efficiently express the therapeutic protein of their choice.