Technology-mediated task settings are rich interactional domains in which second language (L2) learners manage a multitude of interactional resources for task accomplishment. The affordances of these settings have been repeatedly addressed in computer-assisted language learning (CALL) literature mainly based on theory-informed task design principles oriented to the elicitation of structured learning outcomes. However, such focus on design and outcome has left unexplored the great diversity of emergent interactional resources that learners deploy in situ. With this in mind, and using conversation analysis (CA) as the research methodology, this study sets out to describe the task engagement processes of L2 learners who collaboratively engage in online tasks. A close look into screen-recorded interactions of geographically dispersed participants shows that they orient to numerous context-specific interactional resources, which also locates a process-oriented interactional development site for further examination. To this end, the study presents a longitudinal conversation analytic treatment of a focal participant's context-specific interactional behaviors. The findings explicate the emergence and diversification of interactional resources, thus evidencing task-induced development of L2 interactional competence (IC). By providing participant-oriented, situated, qualitative insights into interactional development in and through online task-oriented L2 interactions, the study contributes to CALL, task design, and L2 IC based on methodological underpinnings of CA.