  GRB 190829A at z=0.0785 is the fourth closest long GRB ever detected by the
Neil Gehrels Swift observatory, and the third confirmed case with a very high
energy component. We present our multi-wavelength analysis of this rare event,
focusing on its early stages of evolution, and including data from Swift, the
MASTER global network of optical telescopes, ALMA, and ATCA. We report
sensitive limits on the linear polarization of the optical emission,
disfavouring models of off-axis jets to explain the delayed afterglow peak. The
study of the multi-wavelength light curves and broadband spectra supports a
model with at least two emission components: a bright reverse shock emission,
visible at early times in the optical and X-rays and, later, in the radio band;
and a forward shock component dominating at later times and lower radio
frequencies. A combined study of the prompt and afterglow properties shows many
similarities with cosmological long GRBs, suggesting that GRB 190829A is an
example of classical GRBs in the nearby universe.
