After stepping down as CEO of Stack Overflow, Joel Spolsky has taken on a new chapter—not as a retiree, but as an active chairman and mentor for multiple companies. He describes this period as a sabbatical, filled with fresh challenges and discoveries. Below, we explore how he's spending his time, from overseeing Glitch (formerly Fog Creek Software) to nurturing HASH, an ambitious open-source simulation platform. Spoiler alert: Cooper the Dog is also on the lookout for a web app mascot gig.
What is Joel Spolsky doing after leaving the CEO role at Stack Overflow?
Joel hasn't slowed down. He now serves as chairman of three companies: Stack Overflow, where he still joins customer calls and meets weekly with new CEO Prashanth Chandrasekar; Glitch (formerly Fog Creek Software), which offers a simplified coding environment; and HASH, a platform for building agent-based simulations. He also spends time with his two-year-old dog Cooper, who, Joel jokes, is available as a mascot for any web app. Rather than retiring, Joel describes this phase as a sabbatical—a chance to explore areas he didn't fully grasp while running a medium-sized company.
Why does Joel call this a sabbatical instead of retirement?
Joel lives in what he calls Manhattan's premier NORC—Naturally Occurring Retirement Community—but he's far from idle. He notes that watching Prashanth restructure Stack Overflow has been eye-opening: Joel realized how little he knew about running a company of that scale. This honest reflection fuels his passion for mentoring and learning. He's been incredibly busy, so he wrote this update to avoid fielding endless questions about his activities. The word 'sabbatical' fits because he's still engaged, learning, and contributing—just not as CEO of a single firm. He enjoys the freedom to explore new ventures while staying deeply involved in tech.
What is Glitch and how does it differ from traditional coding platforms?
Glitch, rebranded from Fog Creek Software, is described as the friendly community for building the web
. Under CEO Anil Dash, it has grown to millions of apps and raised significant funding. The platform targets the quiet majority
of developers who don't need complex features like git branches or multistep deployments. Instead, they want a streamlined environment where they can write code and have it run immediately. Joel believes every era needs such a simplified programming tool, and Glitch fills that niche. It's a space for rapid prototyping, collaboration, and learning—perfect for beginners and experienced coders alike when speed trumps configuration.
What is HASH and what problem does it solve?
HASH is an open-source platform for agent-based simulations, just emerging from stealth mode. It lets modelers define how individual agents behave—for example, a commuter deciding whether to take a bus—and then simulate millions of interactions to see what emerges. This is incredibly useful when there's no simple formula to predict outcomes, such as the traffic impact of a new bus route. Traditional methods assume each bus removes 50 cars, but that fails because not everyone will switch. HASH allows city planners to test thousands of route variations, observe which ones actually reduce congestion, and present data-driven cases. The simulations are computationally heavy but provide real insight into complex systems like traffic, epidemiology, or market dynamics.
How does agent-based modeling work in HASH, using the bus route example?
Imagine a city planner wants to justify a new bus line. They could assume each bus takes 50 cars off the road—but that's unrealistic because commuters only switch if the bus saves them time and money. In HASH, each commuter is an agent with its own decision rules. The planner simulates how agents react to different bus routes: Will taking this bus be faster than driving?
The simulation runs these decisions for thousands of agents, revealing whether traffic actually drops. Then the planner can iterate, testing millions of route variations. This agent-based approach works even when you don't have a closed-form equation for the system. It's like running mini Cities: Skylines
experiments, but with real policy implications. HASH makes this kind of heavy computation accessible to non-programmers, helping turn complex social questions into testable models.
What is Joel's role at Stack Overflow today?
While no longer CEO, Joel remains chairman and stays connected. He still joins some customer calls and has a weekly meeting with new CEO Prashanth Chandrasekar. This transition has freed up significant time for Joel, and he admits it's satisfying to watch Prashanth rearrange the company—proving that the best outcome for Joel is that Prashanth does a much better job running Stack Overflow. Joel finds it humbling to discover how much he didn't know about running medium-sized companies. He describes this as a really satisfying realization
, because it means the company is in capable hands, and Joel can focus on his other ventures without guilt.