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Y Combinator | 36 min

Fresh off the launch of Opus 5, Claude Code creator Boris Cherny joins Diana Hu at Startup School 2026 to talk about what the newest models can do, how Claude Code came to be, and what it means to build products when the The central thesis is that current AI models possess significant unrealized capabilities due to restrictive product design and overly specific instructions. The clusters detail how Opus 5's advancements in prompt injection resistance enable safer agent design.

Hobbling prevents AI from realizing its full potential

Many AI products and prompts inadvertently 'hobble' models by providing overly specific, step-by-step instructions, preventing them from utilizing their advanced problem-solving abilities. This creates 'product overhang,' where the model's true capabilities are not realized.

The solution is to give models harder, higher-level tasks, defining the desired outcome and constraints (guardrails and exit criteria) rather than dictating the process. This allows the model to 'cook' and find optimal solutions.

This framework is crucial for founders and builders because it shifts the paradigm from micro-managing AI to empowering it. By understanding and applying 'unhobbling,' they can design products that truly leverage the cutting-edge capabilities of models, leading to more innovative, efficient, and powerful solutions that might otherwise remain undiscovered.

Founders should rethink their prompt engineering strategies, moving away from overly prescriptive instructions towards defining clear objectives, constraints, and success metrics. This allows models to autonomously explore and execute complex tasks, potentially yielding superior and more creative solutions.

Enhanced AI safety enables more robust agent design

Opus 5 has largely overcome prompt injection vulnerabilities, a critical security flaw that previously allowed malicious external instructions to override a model's intended behavior. This enhanced safety means developers can build more reliable and secure AI agents.

Concurrently, models like Opus 5 demonstrate remarkable capabilities, such as rewriting entire codebases between languages in days, a task that previously required years of human effort.

For founders and developers, improved prompt injection resistance drastically reduces security risks, enabling the creation of more trustworthy and scalable AI products. The ability to automate complex engineering tasks like code migration offers immense value, accelerating product development and modernization efforts, and opening doors to previously unfeasible projects.

Developers should prioritize leveraging Opus 5's enhanced security for agent design and explore its capabilities for large-scale code transformation projects. This allows for faster iteration, reduced technical debt, and the ability to tackle ambitious engineering challenges with unprecedented efficiency.

Playful experimentation uncovers AI's hidden talents

Models often possess capabilities that are not immediately obvious or were not explicitly part of their training data. Through creative experimentation and a willingness to 'play' with the model, users can discover these hidden talents.

This 'solicitation gap' highlights that the model's ability to perform a task depends heavily on how it is asked, not just what it was trained on.

For innovators, this means that the potential of AI models extends beyond their documented features. Fostering a culture of playful exploration can lead to groundbreaking discoveries and novel applications, giving early adopters a significant competitive advantage by unlocking unique functionalities.

Organizations should allocate resources and time for 'AI play days' or hackathons, encouraging engineers and product teams to experiment freely with models. This can lead to unexpected product features, efficiency gains, or entirely new business opportunities.

Human expertise shifts to complex systems as AI automates application code

AI's capabilities in coding are advancing rapidly, solving many application-level tasks. However, complex areas like deep systems programming, distributed systems architecture, and precise UI/UX verification still present significant challenges for AI.

This means human developers will shift their focus to these more intricate problems. The most valuable skills for future computer scientists will be the ability to apply technical knowledge to real-world problems, combined with a strong understanding of business, design, and user needs, moving beyond purely theoretical computer science.

This insight is vital for founders, leaders, and educators. It clarifies where human talent remains indispensable and guides the development of future skills.

Investing in interdisciplinary education and fostering problem-solving mindsets will be key to building successful teams and products in an AI-augmented world.

Founders should strategically deploy AI for routine coding tasks, freeing human engineers to focus on complex systems, architectural challenges, and nuanced user experience. Educational institutions should adapt curricula to emphasize practical application, interdisciplinary skills, and problem-solving over rote technical knowledge.

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a16z | 26 min

Recorded live at the New Media Summit, Erik Torenberg sits down with Replit founder and CEO Amjad Masad to discuss founder-led storytelling, building in public, and the role of media in company building. The conversation with Replit CEO Amjad Masad highlights the critical role of storytelling and media engagement for founders. By crafting a compelling narrative, founders can attract talent, capital, and early believers, which are essential for a startup's survival. Authenticity in communication is increasingly valued, and founders should adapt their strategies to engage effectively with their audience.

A startup's story attracts its survival resources

A strong narrative helps founders attract talent, capital, and early believers, which are essential for a startup's survival. By telling a story larger than the company itself, founders can inspire and engage stakeholders.

Without a compelling story, startups may struggle to gain the attention and resources needed to thrive.

Founders should invest time in developing a narrative that resonates with their audience and aligns with their vision.

Authenticity builds trust in founder communication

Audiences today crave authenticity, and founders who communicate genuinely can build stronger, more trusting relationships with their stakeholders. Authenticity can differentiate a founder in a crowded market and foster deeper connections with audiences.

Founders should focus on being authentic in their communications to build trust and engagement.

Align messaging with current conversations

By aligning their messaging with current conversations, founders can increase their visibility and relevance, making it easier to engage with their audience. Effective communication strategies are essential for gaining visibility and engaging with stakeholders.

Founders should stay informed about current trends and conversations to align their messaging accordingly.

Study media dynamics to shape public narrative

By studying how media operates, founders can better navigate interactions with reporters and shape their public narrative. Effective media engagement can enhance a startup's visibility and reputation.

Founders should invest time in understanding media dynamics to improve their media engagement strategies.

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Y Combinator | 31 min

In this conversation from Startup School Paris, Supabase CEO Paul Copplestone explains how a frustrating firebase migration led to an open-source side project that became one of the fastest-growing dev tool companies in Supabase's success story highlights the importance of strategic positioning, community engagement, and operational excellence in the growth of developer tool companies. By positioning itself as an open-source alternative to Firebase and leveraging the strengths of Postgres, Supabase has been able to rapidly grow and gain traction.

Operational excellence beats financial backing

Supabase's experience highlights that financial resources alone are insufficient for success. Instead, achieving product-market fit and maintaining operational excellence are crucial.

This underscores the importance of focusing on core operations and market needs rather than relying solely on financial backing

Founders should prioritize achieving product-market fit and operational excellence over securing large amounts of funding

Open-source positioning drives growth

By branding itself as an open-source alternative to Firebase, Supabase tapped into a market need for open-source solutions, which resonated with developers and helped the company gain significant traction. This strategic positioning allowed Supabase to differentiate itself in a crowded market and attract a dedicated user base

Companies should consider how strategic positioning can differentiate them in the market and attract a specific audience

Community engagement fuels open-source success

The open-source nature of Supabase has fostered a strong community, which has been instrumental in its growth. This community engagement has provided valuable feedback and contributed to the product's development and adoption.

Community engagement can drive product development and adoption, providing a competitive edge in the tech industry

Fostering a strong community around an open-source product can enhance growth and innovation

Adapt to tech trends for growth

Supabase's growth has been driven by its responsiveness to the changing needs of developers and the integration of AI technologies, which has increased user engagement and conversion rates. Adapting to technological trends can significantly enhance a company's growth and relevance in the market

Companies should remain agile and responsive to technological advancements to maintain growth and competitiveness

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a16z | 1 hr 32 min

Travis Kalanick, Ben Horowitz, and Erik Torenberg reunite to reflect on Uber's early days, the investment that almost happened, and why Kalanick believes the next great technology opportunity lies beyond software. Travis Kalanick discusses the evolution from Uber's early days to his current focus on integrating technology with physical industries. He emphasizes the importance of stealth mode in development, the transition from startup to corporate mentality, and the role of exceptional individuals in entrepreneurship.

Integrating tech with logistics halves production costs

By combining software with manufacturing and logistics, industries like food delivery can achieve unprecedented efficiency and cost-effectiveness. This transformation can lead to new business models and opportunities, reshaping how industries operate and compete.

Some may argue that the initial investment in such technologies is too high, but long-term gains could outweigh these costs

Invest in technologies that integrate software with physical processes to stay competitive in evolving markets

Balanced boards prevent startup crises

Kalanick's approach to fundraising and strategic decisions were pivotal in Uber's growth. However, a more balanced board might have prevented some of the company's later issues.

Understanding the impact of leadership and board dynamics can guide founders in making strategic decisions that support sustainable growth

Founders should focus on assembling a board that complements their strengths and addresses potential weaknesses

Exceptional leaders outshine great ideas

The ability to execute and adapt is often more critical than the initial idea, as it determines a company's ability to navigate challenges and scale. For investors, identifying and supporting talented entrepreneurs can lead to more successful outcomes than focusing solely on the idea

Focus on developing leadership skills and building a strong team to enhance execution capabilities

Stealth mode shields innovation from copycats

Operating in stealth mode allows companies to develop their products without external pressures and distractions, potentially leading to more innovative outcomes. This approach can be particularly beneficial in competitive industries where early exposure could lead to copycat strategies from competitors

Consider stealth mode for projects that require significant R&D or are in highly competitive markets

While stealth mode can protect innovation, it may also limit early feedback that could refine the product

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