The unprecedented racial justice movements of 2020, intensified by George Floyd's tragic murder, catalyzed a global mobilization. This dissertation investigates the intersection of these movements with sociotechnical tools that shaped the movement, focusing on the youth deeply engaged with socioalgorithmic systems and their developmental experiences. Article 1 introduces a theoretical framework to understand modern developmental ecologies through a socioalgorithmic lens. It argues for a pivot in the field of developmental science toward studying the technical facets of digital environments, recognizing algorithms shape not just social interactions and political awareness, but also broader psychological and biological processes. Amid 2020's racial justice uprisings, the article underscores the urgency to investigate how algorithmic mediation influences developmental processes like socio-political identity development, moving beyond the discourse on screen time to scrutinize the roles of technological structures in shaping development. Article 2 presents an empirical study examining the impact of algorithmic bias on Black youth during 2020's tumultuous events. Investigating whether ethnic-racial identity exploration activities buffer against the detrimental mental health effects of algorithmic bias in AI selfie filters, the research integrates racial identity development theories with the psychology of systemic racism. Findings illuminate the complex interactions between socioalgorithmic systems and mental health outcomes in racially marginalized youth, highlighting the non-neutrality of algorithms and their potential to reinforce societal biases. The third article conducts an algorithmic audit of YouTube's search engine regarding Black Lives Matter movement content. This audit critically assesses the digital spaces that youth interact with, analyzing the biases embedded in such search algorithms. The findings suggest although many aspects of the Black Lives Matter movement were represented to be in alignment of the organizer's values, the more radical black liberatory ideas associated with "abolition" are represented more negatively in the content curated by YouTube search. By examining the confluence of algorithmic systems and racial justice activism in 2020, my dissertation advocates for a developmental science paradigm that integrates socioalgorithmic context. It aims to enrich understanding of the digital age's impact on the developmental trajectories of racially marginalized youth and calls for incorporating algorithmic systems analysis into the broader understanding of human development. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]