Life On The Pledge: Eric Byrenius

About Erik

Erik Byrenius, the founder of Mudcake, is an entrepreneur and philanthropist whose career path is rooted in a deep-seated curiosity and a commitment to global impact. While studying engineering, his interests broadened significantly, leading him to become actively involved in human rights issues, specifically focusing on press freedom in East Africa. This exposure was instrumental, serving to highlight stark global inequalities and his own Swedish privilege.

The founding of his startup, Mudcake, was a crucial next step, teaching him that small, focused organizations making bold bets can achieve an outsized impact per dollar that is often unattainable for larger institutions. Today, Byrenius applies this strategic lesson to his current endeavors, seeking to maximize the overall impact of his time and capital through both investing and philanthropy, always employing the same lens to identify and support neglected, high-upside opportunities worldwide.

What first drew you to the Founders Pledge and what motivated you to make the pledge?

Shortly after my first exit, I met David Goldberg, who was expanding Founders Pledge beyond the UK. I already knew I wanted to dedicate a portion of my current and future capital to philanthropy, so joining Founders Pledge was a no-brainer. The pledge gave me access to world-class research, practical expertise in effective giving, and a community of thoughtful peers. By hosting events and helping introduce the idea to founders and investors in the Nordics, I also gained a deeper understanding of how Founders Pledge can create real value.

How has your Founders Pledge experience changed the way you think about impact?

I joined for the research but stayed for the community. The mix of deep expertise in structured philanthropy, a wide network, and people who challenge assumptions with humility is unique.

I used to focus on charities with proven short-term results, but Founders Pledge opened my eyes to the value of high-upside uncertainty. I now approach philanthropy like venture investing: a portfolio of bold, evidence-informed bets where a few successes can change the world. Early, unproven nonprofits often lack funding to test ideas at scale, so even small grants can be catalytic.

What have you most valued about being a Founders Pledge member?

Three things stand out to me. First, the depth and clarity of the research. It’s actionable, not theoretical. Second, the team’s genuine curiosity about my approach and readiness to challenge it. Third, the culture of sharing insights from the frontier of effective giving. Together, that combination makes Founders Pledge uniquely valuable.

What charitable organisation(s) do you support and what motivated you to do so?

My portfolio targets diversification and high expected impact, with room for learning. I support work in global security (CISAC in biosecurity, CHAI in AI), physical health (e.g. Helen Keller Intl, Suvita, Taimaka), mental health (StrongMinds), policy (J-PAL's IGI), climate (both nonprofits and for-profits), and meta giving (FP Opex and the Patient Philanthropy Fund).

Going forward, I plan to expand my early-stage nonprofit portfolio with more bold, high-upside bets, similar to Suvita and Taimaka when I first supported them.

What’s one question you would like to ask a philanthropic expert at Founders Pledge?

What is the most effective way to identify and support a broad pipeline of promising early-stage nonprofits, maximizing learning within the first 12 to 24 months while preserving upside if their thesis proves right?