We report on the zero-field-cooled exchange bias (EB) and domain wall dynamics in IrMn (111)/Fe2CoSi bilayers. Essentially, a room temperature exchange bias without field cooling in the bilayers is evidenced and the same is attributed to (111) crystal plane orientation of IrMn layer. The crystal plane orientation of IrMn is confirmed with GI–XRD and selected area electron diffraction (SAED) pattern using transmission electron microscope (TEM). Evolution of exchange bias is evidenced with the thicknesses of Fe2CoSi layer. Indeed, there is perfect correlation between the bulk magnetization measurements and microscopic data obtained from longitudinal magneto-optical Kerr effect (L-MOKE). L-MOKE measurements infer the single-layer Fe2CoSi films are isotropic in nature; however, bilayers of IrMn/Fe2CoSi are anisotropic and unidirectional in nature. Our micro-magnetic simulations infer pinning of the spins at the interface and support aforementioned results and lead to new idea about the exchange mechanism. Present results would indeed be helpful for future spintronic device applications. © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.