During the coronavirus disease 2019 (COVID-19) outbreak, physical distancing restrictions led to the cancellation of live, large group events worldwide. These included weekly educational conferences required of emergency medicine (EM) residency programmes in the USA. Specifically, the Residency Review Committee in EM under the Accreditation Council for Graduate Medical Education has mandated that there be at least 4 hours per week of synchronous conference didactics.1 Increased clinical and administrative demands during the COVID-19 pandemic have challenged programmes to transition traditional curricula to online platforms. In an effort to mirror a traditional in-person conference experience, we at Academic Life in Emergency Medicine (ALiEM) launched ALiEM Connect (ALiEM, San Francisco, CA, USA), incorporating a livestream video of presentations with concurrent backchannel (informal, non-public, secondary conversation) discussions. Although several teleconferencing applications exist, the distribution of an interactive conference to 1080 learners on 64 United States residency programmes necessitated a novel, scalable approach, which no existing platform offered with standard plans. Six nationally known speakers taught during the 2-hour event, in which 20 minutes were allotted to each speaker. We utilised Zoom™ (Zoom Video Communications Inc., San Jose, CA, USA) to host speakers in view of its capability to stream on to YouTube Live (YouTube, San Bruno, CA, USA). Participants watched the stream via YouTube, and synchronous backchannel discussion with learners, educators and speakers was facilitated through a closed Slack (Slack Technologies, San Francisco, CA, USA) messaging platform restricted to registered residency programmes. Learners engaged in large group channels dedicated to each speaker and in their own small group, programme-specific channels. This structure provided an organised approach to engaging in multiple simultaneous discussions. Moderators relayed questions from learners on Slack to speakers on Zoom during live question-and-answer segments. The adoption of any new digital platform is often challenging for both first-time and seasoned users. Preliminary survey data suggest that most residents were unfamiliar with Slack and may have felt reserved about navigating the platform during discussion; we note that it is challenging in this context to establish the psychological safety some residents need to empower them to comment and pose questions. From the ALiEM Connect team’s perspective, the live format required in-the-moment adaptability to unanticipated obstacles, such as unpredictable initial linkages between Zoom and YouTube, the crashing of the website caused by the initial surge of traffic, and the inability of speakers to screenshare presentation slides. Nonetheless, our event highlighted a successful, scalable and engaged way to host a live online conference. It allowed for engagement within and across multiple programmes spanning the country and real-time access to national experts, effectively creating a virtual community of practice in a ‘mega-grand rounds’ format. An unexpected benefit of the Slack backchannel was that trainees seemed especially engaged in their programme’s small group channel, on which they discussed the lecture topic, told stories of their hospital experiences, shared literature and even added humour to the conversation, thereby mimicking behaviours common to in-person conferences. Overall, resident feedback was overwhelmingly positive. In comparison with prior in-person conference experiences, 84% of residents felt that ALiEM Connect was the same or better in quality and 93% enjoyed the event overall. Thus, although learners must remain physically distant during the COVID-19 pandemic, we offer a model for massive, online, interactive conferencing that allows for social connection and academic engagement amongst residents.