  The collection of planetary system properties derived from large surveys such
as Kepler provides critical constraints on planet formation and evolution.
These constraints can only be applied to planet formation models, however, if
the observational biases and selection effects are properly accounted for. Here
we show how epos, the Exoplanet Population Observation Simulator, can be used
to constrain planet formation models by comparing the Bern planet population
synthesis models to the Kepler exoplanetary systems. We compile a series of
diagnostics, based on occurrence rates of different classes of planets and the
architectures of multi-planet systems, that can be used as benchmarks for
future and current modeling efforts. Overall, we find that a model with 100
seed planetary cores per protoplanetary disk provides a reasonable match to
most diagnostics. Based on these diagnostics we identify physical properties
and processes that would result in the Bern model more closely matching the
known planetary systems. These are: moving the planet trap at the inner disk
edge outward; increasing the formation efficiency of mini-Neptunes; and
reducing the fraction of stars that form observable planets. We conclude with
an outlook on the composition of planets in the habitable zone, and highlight
that the majority of simulated planets smaller than 1.7 Earth radii have
substantial hydrogen atmospheres.
  The software used in this paper is available online for public scrutiny at
https://github.com/GijsMulders/epos
