The paper discusses the constraints on massive particles during inflation, using the BOSS (Baryonic Online Spectroscopic Survey) redshift-space galaxy power spectrum and bispectrum multipoles, as well as *Planck* CMB non-Gaussianity data. The authors demonstrate that some Cosmological Collider models can be well approximated by the standard equilateral and orthogonal parametrization, allowing them to translate *Planck* non-Gaussianity constraints into bounds on Collider models. They also show that many models have signatures that are not degenerate with equilateral and orthogonal non-Gaussianity, requiring dedicated searches. The study focuses on spin-zero particles in the principal series and constrains their couplings to the inflaton at varying speeds and masses, marginalizing over unknown inflaton self-interactions. This is achieved through improved Cosmological Bootstrap techniques and the combination of perturbation theory and halo occupation distribution models for galaxy clustering. The work sets a standard for inflationary spectroscopy with cosmological observations, providing a link between physics on the largest and smallest scales.The paper discusses the constraints on massive particles during inflation, using the BOSS (Baryonic Online Spectroscopic Survey) redshift-space galaxy power spectrum and bispectrum multipoles, as well as *Planck* CMB non-Gaussianity data. The authors demonstrate that some Cosmological Collider models can be well approximated by the standard equilateral and orthogonal parametrization, allowing them to translate *Planck* non-Gaussianity constraints into bounds on Collider models. They also show that many models have signatures that are not degenerate with equilateral and orthogonal non-Gaussianity, requiring dedicated searches. The study focuses on spin-zero particles in the principal series and constrains their couplings to the inflaton at varying speeds and masses, marginalizing over unknown inflaton self-interactions. This is achieved through improved Cosmological Bootstrap techniques and the combination of perturbation theory and halo occupation distribution models for galaxy clustering. The work sets a standard for inflationary spectroscopy with cosmological observations, providing a link between physics on the largest and smallest scales.