Life After CEO: Joel Spolsky on Sabbaticals, New Ventures, and Agent-Based Simulations

In this Q&A, Joel Spolsky, the former CEO of Stack Overflow, opens up about his life after stepping down. He now serves as chairman of three companies, including Glitch and HASH, and explains why he calls this period a sabbatical rather than retirement. Let's dive into his insights.

1. What Is Joel Spolsky Doing After Leaving the CEO Role at Stack Overflow?

Joel Spolsky has transitioned from the day-to-day CEO duties at Stack Overflow to a chairman role. He continues to join customer calls and meet weekly with the new CEO, Prashanth Chandrasekar. Meanwhile, he chairs two other companies: Glitch (formerly Fog Creek Software) and HASH. He also spends time with his two-year-old dog, Cooper. Despite being busy, he emphasizes this is a sabbatical, not retirement—a chance to learn and explore new challenges.

2. How Does He Feel About the Handover to Prashanth Chandrasekar?

Spolsky finds deep satisfaction in watching Prashanth transform the company. He admits that he didn't fully grasp the nuances of running a medium-sized business, and seeing Prashanth improve operations is rewarding. For Spolsky, the best possible outcome is that Prashanth excels, proving that he was perhaps not the ideal CEO himself. This humility and openness to learning characterize his current mindset.

3. Why Does He Call This a Sabbatical Instead of Retirement?

Spolsky lives in what he jokingly calls a "Naturally Occurring Retirement Community" in Manhattan, but he insists he isn't retired. He is busier than ever, juggling board duties, strategic guidance, and personal projects. Calling it a sabbatical reflects his desire to keep growing, avoid the stigma of retirement, and maintain a flexible schedule that still allows for significant contributions to the tech world.

4. What Is Glitch and Who Does It Serve?

Glitch, originally Fog Creek Software, is now a friendly community for building the web. Under CEO Anil Dash, it has grown to millions of apps. Spolsky believes every era needs a simplified programming environment for the majority of developers who don't require complex features like git branches or multistep deployments. Glitch fills this gap, letting users write code and run it instantly.

5. What Is HASH and What Problem Does It Solve?

HASH is an open-source platform for building agent-based simulations. It helps model problems where individual behaviors are known but aggregate outcomes are unpredictable—like traffic patterns, epidemiology, or market dynamics. The platform allows users to simulate millions of scenarios, providing insights that traditional formulas can't offer. Spolsky highlights its potential for urban planning, such as testing bus routes to reduce congestion.

6. Can You Walk Through an Example of HASH in Action for Traffic Planning?

Imagine you're a city planner wanting to add a new bus line. You could assume each bus removes 50 cars, but that only works if 50 commuters choose the bus. Real people decide based on time and cost savings. HASH simulates each commuter as an agent, modeling their decision-making. It then tests thousands of potential routes to find which ones actually reduce traffic. This computational approach works even when no simple formula exists.

7. What Other Roles Does He Hold?

Beyond Stack Overflow, Spolsky is chairman of Glitch and HASH. He provides strategic oversight, connects leaders with resources, and helps shape company vision. While he no longer manages daily operations, his experience guides these startups. He also enjoys being a mentor and observer, learning from the new CEOs' approaches.