What Every Startup Should Learn from Varun Mohan: A Conversation with the CEO of Windsurf

arun Mohan, co-founder and CEO of Windsurf, has navigated a remarkable journey from GPU virtualization to revolutionizing software development with AI-driven coding tools.

In a candid conversation with Y Combinator, Mohan shared insights that every startup founder can learn from. His story is one of bold pivots, relentless realism, and a commitment to staying ahead of the technological curve.

Below, we distill the key lessons from his journey, highlighting pivotal quotes that encapsulate his philosophy.

1. Embrace Bold Pivots as a Badge of Honor

Startups often face moments where their original thesis no longer holds. Mohan’s journey began with ExoFunction, a GPU virtualization company, but in 2022, he and his team made a daring decision to pivot to Codium (later Windsurf) after recognizing the commoditization risk in their original business.

“We did it within a weekend… I don’t think this is going to work, we don’t think we know how to scale this company.”

This rapid pivot, executed with just eight employees and $28 million raised, underscores the importance of acting decisively when the market shifts. Mohan encourages founders to view pivots not as failures but as courageous steps toward success.

Takeaway for Startups: Don’t cling to a failing idea out of pride. Treat pivots as opportunities to realign with market realities and pursue a path with greater potential. Speed is critical—hesitation can cost you your competitive edge.

2. Balance Irrational Optimism with Uncompromising Realism

Mohan’s decision to challenge GitHub Copilot, a seemingly unbeatable incumbent, was fueled by a blend of audacity and pragmatism. He describes this duality as essential for startups.

“Startups require two distinct beliefs… you need this irrational optimism because if you don’t have the optimism, you just won’t do anything… and you need uncompromising realism which is that when the facts change, you actually change your mind.”

This balance allowed Windsurf to take on giants like Microsoft while staying grounded enough to adapt when their initial product lagged behind Copilot.

Takeaway for Startups: Dream big and believe in your potential to disrupt, but stay vigilant about market signals. When evidence suggests a course correction, act swiftly rather than doubling down on a flawed strategy.

3. Move Fast to Ship and Iterate

Windsurf’s ability to ship a VS Code extension just two months after pivoting, despite using an inferior open-source model, demonstrates the power of speed and iteration.

“We built a VS code extension after pivot within I think 2 months, we had shipped the product and given it out to HackerNews.”

This rapid deployment allowed Windsurf to gather feedback, refine their model, and eventually surpass Copilot in key capabilities like code completion in the middle of lines.

Takeaway for Startups: Don’t wait for perfection. Launch a minimum viable product quickly to test your assumptions and learn from real-world usage. Iteration based on user feedback is more valuable than a flawless initial release.

4. Build for Excitement and Alignment

When pivoting to Codium, Mohan prioritized a direction that energized his team.

“We needed to pick something that actually everyone at the company was going to be excited about… if we had picked something that people were not excited about, we would fail immediately.”

This focus on team enthusiasm ensured that Windsurf’s small crew of eight could rally around a shared vision, even in the face of daunting competition.

Takeaway for Startups: Choose projects that ignite passion within your team. A motivated team is more likely to overcome challenges and deliver exceptional results, especially in resource-constrained environments.

5. Recognize That All Insights Depreciate

Mohan emphasizes that technological advantages are fleeting, requiring constant innovation to stay ahead.

“Every single insight that we have is a depreciating insight… the reason why companies win is not like they had a tech insight like one year ago, it’s actually a compounding tech advantage.”

Windsurf’s shift from Codium to a full-fledged IDE (Windsurf) was driven by the realization that agentic coding was the future, a bet made before it became an industry norm.

Takeaway for Startups: Treat your current advantages as temporary. Continuously seek new insights and invest in technologies that position you at the frontier of your industry. Stagnation is a slow death.

6. Leverage Strong Evaluations to Drive Complexity

Windsurf’s sophisticated system for understanding large codebases, which combines keyword search, abstract syntax tree parsing, and GPU-accelerated ranking, was born out of rigorous evaluations rather than arbitrary complexity.

“We strive for what works… we built really good evaluation systems… code you can leverage a property of code which it can be run.”

By using open-source project commits and unit tests, Windsurf created a “hill to climb” that guided their development, ensuring every addition improved performance.

Takeaway for Startups: Build robust evaluation systems to measure progress objectively. This prevents wasteful complexity and ensures your product evolves in ways that deliver real value.

7. Focus on High-Value, Underserved Niches

Mohan sees untapped potential in specific, high-impact areas of software development.

“I’ve not really seen a lot of startups in the space that are just like we do this one thing really really well… like Java migrations… the amount that people spend on this is probably billions if not tens of billions of dollars.”

He highlights opportunities like COBOL-to-Java migrations or automated bug resolution, which are economically significant but underserved by current solutions.

Takeaway for Startups: Look for niche problems with massive economic impact. Solving these well can carve out a defensible market position, even in a crowded AI landscape.

8. Empower Non-Technical Builders

Windsurf’s unexpected success with non-technical users, who use its agent Cascade without touching code, points to a future where software development is democratized.

“There’s actually a non-trivial chunk of our developers that have never opened the editor up and they just live in Cascade… they can click on things and make changes.”

This aligns with Mohan’s vision of a world where everyone is a “builder,” creating custom software tailored to their needs.

Takeaway for Startups: Consider how your product can empower non-technical users. Broadening your addressable market to include domain experts without coding skills can unlock significant growth opportunities.

9. Stay Resilient Against Competitive Noise

Windsurf’s morale remains unaffected by competitors, a resilience forged through turbulent times like their pivot.

“Our company just doesn’t have like morale is not really affected by what other companies do… we needed to pivot at 10 employees and just completely kill our idea.”

Instead of obsessing over rivals like Cursor or GitHub Copilot, Windsurf focuses on its long-term strategy and execution.

Takeaway for Startups: Don’t let competitors distract you from your vision. Focus on your unique value proposition and maintain confidence in your ability to adapt and innovate.

10. Change Your Mind Faster Than You Think

Reflecting on his journey, Mohan’s advice to his younger self is a powerful lesson for all founders.

“The biggest thing I would say is change your mind much much faster than you believe is reasonable… pivot as quickly as possible and treat pivots as a badge of honor.”

This mindset allowed Windsurf to evolve rapidly, from GPU infrastructure to AI coding tools, and ultimately to a full IDE.

Takeaway for Startups: Be willing to abandon ideas that no longer serve your goals. Speedy adaptation is a competitive advantage in fast-moving industries like AI.

Varun Mohan’s journey with Windsurf is a masterclass in startup resilience, adaptability, and foresight. From a weekend pivot to building a tool that supercharges developers and non-technical builders alike, his story offers timeless lessons.

Startups should embrace bold pivots, balance optimism with realism, ship quickly, and focus on compounding advantages.