Feature assignment differs significantly from featural agreement as it involves aspects that are not directly manifested in the linguistic input to the speaker (like the Accusative feature of the transitive verb) but are accessible from the knowledge component only. This work is an overview of a research program that aims to explore key aspects of syntactic encoding in the structural realm of feature assignment from an experimental perspective. The project is innovative because we pit the existing models of encoding syntactic agreement against new experimental data pertaining to feature assignment effects, exploring, in particular, the role of working memory in real time computation of featural assignment. We focus on feature assignment phenomena in two Slavic languages, Bulgarian and Russian, which possess rich morphological repertoires, thus providing an excellent testing ground from an experimental perspective.