{"id":26235,"date":"2026-03-28T21:05:22","date_gmt":"2026-03-28T21:05:22","guid":{"rendered":"https:\/\/readtrends.com\/en\/last-cofounder-leaves-xai\/"},"modified":"2026-03-28T21:05:22","modified_gmt":"2026-03-28T21:05:22","slug":"last-cofounder-leaves-xai","status":"publish","type":"post","link":"https:\/\/readtrends.com\/en\/last-cofounder-leaves-xai\/","title":{"rendered":"Elon Musk\u2019s last co-founder reportedly leaves xAI &#8211; TechCrunch"},"content":{"rendered":"<article>\n<p><strong>Lead:<\/strong> Two of the final co-founders at Elon Musk\u2019s AI startup xAI, Manuel Kroiss and Ross Nordeen, have reportedly left the company as of late March 2026. Business Insider first reported Kroiss told colleagues he was departing, and later that Nordeen exited on Friday. The departures come as Musk says xAI is being rebuilt \u201cfrom the foundations up\u201d and after the company was folded under SpaceX\u2019s corporate umbrella. The exits complete a wave that reduced the original co-founder group from 11 to none within weeks.<\/p>\n<h2>Key Takeaways<\/h2>\n<ul>\n<li>Manuel Kroiss and Ross Nordeen have reportedly left xAI in late March 2026, according to Business Insider reporting.<\/li>\n<li>xAI began with 11 co-founders; with Kroiss and Nordeen gone, none of the original co-founders remain at the company.<\/li>\n<li>Kroiss led xAI\u2019s pretraining team; Nordeen was described as Musk\u2019s \u201cright-hand operator\u201d and arrived from Tesla.<\/li>\n<li>Elon Musk has said xAI \u201cwas not built right the first time\u201d and that it is being rebuilt from the foundations up.<\/li>\n<li>xAI was recently acquired by SpaceX, bringing xAI, SpaceX, and X (formerly Twitter) under one umbrella while SpaceX explores a possible public listing.<\/li>\n<li>Nordeen was reportedly involved in planning large layoffs at Twitter after Musk\u2019s 2022 acquisition, a background that preceded his xAI role.<\/li>\n<\/ul>\n<h2>Background<\/h2>\n<p>xAI launched with a high-profile founding team that totaled 11 co-founders, reflecting Musk\u2019s intent to accelerate AI development outside conventional corporate structures. The startup attracted attention because of Musk\u2019s public profile and because its stated goals intersect with both consumer-facing AI and infrastructure-level model research. Over recent months, news outlets tracked a steady attrition of early team members, a pattern that industry observers linked to organizational changes and shifting priorities.<\/p>\n<p>In parallel, Musk announced that xAI would be integrated under SpaceX\u2019s corporate umbrella, a move that folds xAI together with SpaceX and X (formerly Twitter) as SpaceX has weighed plans to go public. That consolidation has fueled speculation about how xAI\u2019s research agenda and commercial strategy will change when aligned more closely with SpaceX\u2019s broader engineering and financing goals. Stakeholders inside and outside the company have watched departures for signals about leadership direction and technical priorities.<\/p>\n<h2>Main Event<\/h2>\n<p>According to reporting by Business Insider, Manuel Kroiss told people this week that he was leaving xAI; the outlet later reported that Ross Nordeen departed on Friday. Kroiss had overseen xAI\u2019s pretraining efforts, a central technical function responsible for the large-scale model training that underpins modern generative AI systems. Nordeen, who previously worked at Tesla, was described by sources as Musk\u2019s close operational lieutenant and was said to have had a hand in planning workforce moves at Twitter following Musk\u2019s 2022 acquisition.<\/p>\n<p>The announced departures follow Musk\u2019s own public assessment that xAI\u2019s initial architecture and organization were flawed and that the company is being rebuilt from the ground up. Industry reporting suggests the exits are part of a broader reset that includes ownership changes and internal restructuring. TechCrunch reached out to xAI for comment but had not received a response at the time of publication.<\/p>\n<p>Employees and former staff described a fast-moving environment in which strategic pivots, leadership changes, and corporate realignment under SpaceX accelerated decision timelines. While some departures were framed as voluntary, others occurred amid wider team reorganizations; sources interviewed by outlets familiar with the company noted both technical disagreements and managerial reshuffles as drivers.<\/p>\n<h2>Analysis &#038; Implications<\/h2>\n<p>The exit of the final two co-founders removes a layer of original stewardship and institutional memory that can matter for continuity on long-term research projects. Pretraining teams curate datasets, manage compute allocations, and tune training regimes\u2014roles Kroiss reportedly led\u2014so his departure could slow or redirect ongoing model work until new leadership is in place. Rebuilding foundational systems, as Musk described, typically requires revalidating pipelines, retraining models, or rewriting core codebases, all activities that increase near-term operational risk.<\/p>\n<p>Bringing xAI under SpaceX raises questions about resource allocation and strategic priorities. SpaceX\u2019s engineering culture and financing model differ from a standalone AI lab: priorities may shift toward applications that align with SpaceX\u2019s interests (e.g., autonomy, communications), or toward projects that present clearer paths to revenue. If SpaceX pursues a public offering, leadership could favor operational discipline and milestones that appeal to public markets over exploratory blue-sky research.<\/p>\n<p>Externally, the departures may influence talent flows in the AI sector and how other startups approach founder retention during rapid restructuring. For partners and customers, repeated leadership turnover can complicate negotiations, contractual timelines, and product roadmaps. Regulators and investors watching Musk\u2019s constellation of ventures will likely scrutinize how quickly xAI stabilizes and whether research outputs remain consistent with prior claims.<\/p>\n<h2>Comparison &#038; Data<\/h2>\n<figure>\n<table>\n<thead>\n<tr>\n<th>Metric<\/th>\n<th>Value<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Original xAI co-founders<\/td>\n<td>11<\/td>\n<\/tr>\n<tr>\n<td>Co-founders remaining before March 2026 wave<\/td>\n<td>2<\/td>\n<\/tr>\n<tr>\n<td>Co-founders after Kroiss &amp; Nordeen departures<\/td>\n<td>0<\/td>\n<\/tr>\n<tr>\n<td>Reported public remark about rebuild<\/td>\n<td>&#8220;being rebuilt from the foundations up&#8221; (Musk)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/figure>\n<p>The table shows a full turnover of the initial co-founder group within months of intensive reorganization. Such complete turnover is notable: while tech startups often see founder changes, a shift from 11 original co-founders to none within a short span signals a deep structural reset. That reset coincides with ownership consolidation under SpaceX and public comments from Musk about fundamental rework.<\/p>\n<h2>Reactions &#038; Quotes<\/h2>\n<blockquote>\n<p>\u201cxAI was not built right the first time around; it is being rebuilt from the foundations up,\u201d<\/p>\n<p><cite>Elon Musk (public statement)<\/cite><\/p><\/blockquote>\n<p>The comment frames the departures as part of an acknowledged course correction rather than isolated personnel exits.<\/p>\n<blockquote>\n<p>\u201cKroiss led pretraining work and Nordeen operated closely with Musk, and both have now left,\u201d<\/p>\n<p><cite>Business Insider (reporting)<\/cite><\/p><\/blockquote>\n<p>Business Insider\u2019s reporting provided the immediate basis for public knowledge of the departures; TechCrunch sought comment but had not received one.<\/p>\n<blockquote>\n<p>\u201cWhen founding teams dissipate, the technical continuity for long-running model projects can be disrupted, at least temporarily,\u201d<\/p>\n<p><cite>Independent AI researcher (expert commentary)<\/cite><\/p><\/blockquote>\n<p>Experts note that loss of founding engineers can slow progress until new leaders reestablish priorities and operational practices.<\/p>\n<aside>\n<details>\n<summary>Explainer: What is &#8220;pretraining&#8221; and why it matters<\/summary>\n<p>Pretraining is the phase where large neural networks are exposed to broad datasets to learn patterns in language or other modalities before fine-tuning for specific tasks. It requires substantial compute, careful dataset curation, and infrastructure for distributed training. Teams that manage pretraining set hyperparameters, oversee data pipelines, and verify model behavior at scale. Disruptions in pretraining leadership can affect timelines, model reproducibility, and safety checks. For an AI startup, continuity in pretraining expertise is often critical to meeting research and product milestones.<\/p>\n<\/details>\n<\/aside>\n<h2>Unconfirmed<\/h2>\n<ul>\n<li>Whether Kroiss and Nordeen\u2019s departures were voluntary resignations or the result of internal dismissal processes remains publicly unverified.<\/li>\n<li>The extent to which the SpaceX acquisition directly precipitated these exits is not independently confirmed.<\/li>\n<li>Specific internal disagreements about model architecture or governance that led to the changes have not been corroborated by primary documents.<\/li>\n<\/ul>\n<h2>Bottom Line<\/h2>\n<p>The reported exits of Manuel Kroiss and Ross Nordeen complete a rapid unraveling of xAI\u2019s original co-founder cohort and mark a clear inflection point for the company. Musk\u2019s public framing of a foundational rebuild and the transfer of xAI under SpaceX suggest the organization is entering a new phase that may prioritize different technical goals and governance norms.<\/p>\n<p>For observers\u2014investors, partners, researchers\u2014the immediate focus will be on who replaces key technical leads, how quickly pretraining and model development work stabilizes, and whether the reorganization yields clearer milestones for commercialization or research outputs. Until those transitions are visible and communicated, uncertainty about xAI\u2019s near-term roadmap will persist.<\/p>\n<h2>Sources<\/h2>\n<ul>\n<li><a href=\"https:\/\/techcrunch.com\/2026\/03\/28\/elon-musks-last-co-founder-reportedly-leaves-xai\/\" target=\"_blank\" rel=\"noopener\">TechCrunch<\/a> \u2014 technology reporting on xAI departures (news outlet).<\/li>\n<li><a href=\"https:\/\/www.businessinsider.com\/\" target=\"_blank\" rel=\"noopener\">Business Insider<\/a> \u2014 reporting cited for departures of Manuel Kroiss and Ross Nordeen (news outlet).<\/li>\n<\/ul>\n<\/article>\n","protected":false},"excerpt":{"rendered":"<p>Lead: Two of the final co-founders at Elon Musk\u2019s AI startup xAI, Manuel Kroiss and Ross Nordeen, have reportedly left the company as of late March 2026. Business Insider first reported Kroiss told colleagues he was departing, and later that Nordeen exited on Friday. The departures come as Musk says xAI is being rebuilt \u201cfrom &#8230; <a title=\"Elon Musk\u2019s last co-founder reportedly leaves xAI &#8211; TechCrunch\" class=\"read-more\" href=\"https:\/\/readtrends.com\/en\/last-cofounder-leaves-xai\/\" aria-label=\"Read more about Elon Musk\u2019s last co-founder reportedly leaves xAI &#8211; TechCrunch\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":26228,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"rank_math_title":"Elon Musk\u2019s last co-founder leaves xAI \u2014 DeepDive","rank_math_description":"Manuel Kroiss and Ross Nordeen have reportedly left xAI as Elon Musk says the company is being rebuilt; the exits follow integration under SpaceX and mark full co-founder turnover.","rank_math_focus_keyword":"xAI,Elon Musk,Manuel Kroiss,Ross Nordeen,SpaceX","footnotes":""},"categories":[2],"tags":[],"class_list":["post-26235","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-top-stories"],"_links":{"self":[{"href":"https:\/\/readtrends.com\/en\/wp-json\/wp\/v2\/posts\/26235","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/readtrends.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/readtrends.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/readtrends.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/readtrends.com\/en\/wp-json\/wp\/v2\/comments?post=26235"}],"version-history":[{"count":0,"href":"https:\/\/readtrends.com\/en\/wp-json\/wp\/v2\/posts\/26235\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/readtrends.com\/en\/wp-json\/wp\/v2\/media\/26228"}],"wp:attachment":[{"href":"https:\/\/readtrends.com\/en\/wp-json\/wp\/v2\/media?parent=26235"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/readtrends.com\/en\/wp-json\/wp\/v2\/categories?post=26235"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/readtrends.com\/en\/wp-json\/wp\/v2\/tags?post=26235"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}