The EU has set ambitious goals to reduce greenhouse gas emissions to combat climate change. The transport sector is a major contributor to these emissions, but the targets for this sector cannot be met with currently available materials technology. Due to the direct link between weight and energy consumption, EU investment in advancing lightweight technologies is crucial. Therefore, fibre-reinforced composites are a key technology, but they are not yet widely used due (1) to their high price, (2) overdesign due to a lack of toughness and (3) difficulties with recycling. Addressing these challenges through fibre-hybridisation requires a highly interdisciplinary team of researchers with a strong background in both modelling and experimentation. Since such combined expertise is scarce, HyFiSyn aims to train 13 early stage researchers to become interdisciplinary, multi-talented experts. The 8 universities, 5 industrial partners and 2 professional training organisations offer the researchers a unique opportunity to be trained by world-leading experts in cutting-edge technologies, where they are supported by a strong network and industry participation. The training programme strongly emphasises entrepreneurship and innovation skills to maximise the impact of the project, thereby increasing the EU’s innovation capacity. Simultaneously, the researchers will be trained through research by developing and experimentally validating advanced simulation tools to predict optimal microstructures for fibre-hybrid composites. These microstructures will then be manufactured and verified in industrial applications. To further increase its impact, HyFiSyn also designs hybrids with smart and functional properties, and will investigate strategies for more efficient usage of recycled fibres through fibre-hybridisation. The overall goal is to fundamentally understand synergetic effects, so that they can be maximally exploited and unprecedented composite performance can be achieved.