Peer Richelsen, co-founder of the scheduling platform Cal.com, recently shared his perspective on strategic reversals, emphasizing that "reverting isn't a weakness" but rather an act of "integrity." Richelsen's comments, posted on social media, highlight the importance of swift recovery over initial missteps, stating, "users remember how fast you recovered not how flashy your mistake was." This philosophy emerges shortly after Cal.com's significant decision to transition its commercial codebase from open source to closed source.
The company announced on April 15, 2026, that it would be moving its core commercial offering to a private repository, citing escalating AI-driven security risks. This move marks a substantial strategic shift for Cal.com, which was initially built and gained prominence as an open-source alternative to established scheduling tools like Calendly. The decision has sparked considerable debate within the open-source community.
Cal.com's co-founder, Bailey Pumfleet, explained the rationale, stating that "open source code is basically like handing out the blueprint to a bank vault," and that "now there are 100x more hackers studying the blueprint." Richelsen himself was quoted in earlier reports, noting that "open source security always relied on people to find and fix any problems," but now "AI attackers are flaunting that transparency." The company pointed to advanced AI models capable of rapidly identifying and exploiting vulnerabilities as a primary driver for the change.
While the commercial version moves to a closed model, Cal.com simultaneously launched Cal.diy, a stripped-down, MIT-licensed open-source version intended for personal and non-production use. This dual approach aims to balance security for enterprise clients with continued support for the open-source community. Critics, however, have questioned the security rationale, suggesting the move could also be a strategy to prevent competitors from forking the codebase.
Richelsen's tweet underscores a leadership approach that prioritizes adaptability and user trust, even when it involves challenging established practices. The strategic pivot by Cal.com reflects a broader industry concern regarding the evolving security landscape, particularly with the proliferation of sophisticated AI tools. The company maintains its commitment to open source principles, stating it would reconsider its stance if the security environment improves.
