  In protoplanetary disks, sufficiently massive planets excite pressure bumps,
which can then be preferred locations for forming new planet cores. We discuss
how this loop may affect the architecture of multi-planet systems, and compare
our predictions with observation. Our main prediction is that low-mass planets
and giant planets can each be divided into two subpopulations with different
levels of mass uniformity. Low-mass planets that can and cannot reach the
pebble isolation mass (the minimum mass required to produce a pressure bump)
develop into intra-similar "Super-Earths" and more diverse "Earths",
respectively. Gas giants that do and do not accrete envelope quickly develop
into intra-similar "Jupiters" and more diverse "Saturns", respectively.
Super-Earths prefer to form long chains via repeated pressure-bump planet
formation, while Jupiter formation is usually terminated at pairs or triplets
due to dynamical instability. These predictions are broadly consistent with
observations. In particular, we discover a previously overlooked mass
uniformity dichotomy among the observed populations of both low-mass planets
(Earths vs. Super-Earths) and gas giants (Saturns vs. Jupiters). For low-mass
planets, planets well below the pebble isolation mass ($\lesssim 3M_\oplus$ or
$\lesssim 1.5 R_\oplus$ for sun-like stars) show significantly higher
intra-system pairwise mass difference than planets around the pebble isolation
mass. For gas giants, the period ratios of intra-system pairs show a bimodal
distribution, which can be interpreted as two subpopulations with different
levels of mass uniformity. These findings suggest that pressure-bump planet
formation could be an important ingredient in shaping planetary architectures.
