  Multi-loop scattering amplitudes constitute a serious bottleneck in current
high-energy physics computations. Obtaining new integrand level representations
with smooth behaviour is crucial for solving this issue, and surpassing the
precision frontier. In this talk, we describe a new technology to rewrite
multi-loop Feynman integrands in such a way that non-physical singularities are
avoided. The method is inspired by the Loop-Tree Duality (LTD) theorem, and
uses geometrical concepts to derive the causal structure of any multi-loop
multi-leg scattering amplitude. This representation makes the integrand much
more stable, allowing faster numerical simulations, and opens the path for
novel re-interpretations of higher-order corrections in QFT.
