  We study how non-Markovianity of an open two-level system can be detected
when continuously monitoring a part of its bosonic environment. Considering a
physical scenario of an atom in a lossy cavity, we demonstrate that the
properties of the time-dependent flux of the photons from the cavity allows the
detection of memory effects in the atomic dynamics, without requiring state nor
process tomography. This framework overlaps with effective descriptions for the
memory part of the environment using pseudomode methods. Our central results
show how the Markovian measurement record on the environment of an enlarged
open system allows to draw conclusions on the non- Markovianity of the original
system of interest.
