Why Great Product Managers Must Have a Side Project

Product managers at the world's biggest tech companies are falling behind. While they optimize mobile apps and SaaS dashboards, a new wave of frontier technology — brain-computer interfaces (BCI), spatial computing, and mixed reality (MR) — is quietly reshaping the industry, and most PMs inside big tech have no idea it is happening.

This is not a theoretical warning. It is a pattern emerging across global tech hubs from Sydney to Shenzhen, where seasoned engineers and product leaders from companies like Tencent, Google, and Meta are discovering that their decade-long tenure inside corporate walls has left them blind to the very technologies that will define the next computing era.

Key Takeaways

• Big tech's 'walled garden effect' traps product managers in a narrow view of technology limited to mobile apps and software platforms
• Brain-computer interfaces and spatial computing represent the next iPhone-level paradigm shift, yet AI capabilities in these domains remain extremely primitive
• A 10-year veteran engineer from Tencent recently left the industry entirely, believing AI had replaced her role — a fundamental misunderstanding of where AI actually falls short
• Product managers with active side projects in frontier tech are better positioned to spot industry shifts before they become mainstream
• AI adoption among creative professionals and PMs in Western markets like Australia remains surprisingly low, despite easy access to tools like ChatGPT and Claude
• The window to build expertise in BCI and spatial computing is open now, precisely because these fields are not yet mainstream

The Walled Garden Effect Is Real — and Dangerous

There is a cognitive trap that ensnares product managers who spend years inside large technology companies. Call it the 'walled garden effect' — the assumption that because you work at a leading tech firm, you are automatically at the cutting edge of innovation.

This assumption is dangerously wrong. Big tech companies like Google, Apple, Meta, and Tencent operate within well-defined product categories: social media, messaging, cloud services, mobile operating systems. Their product managers become world-class experts in optimizing these existing paradigms.

But optimization is not innovation. The next computing platform — the successor to the smartphone — will not emerge from an incremental update to WeChat or Instagram. It will come from the convergence of spatial computing, brain-computer interfaces, and AI. And most big tech PMs have zero exposure to these technologies.

A 10-Year Tencent Engineer Walks Away — For the Wrong Reasons

Consider a real case that illustrates this blind spot perfectly. A backend engineer who spent 10 years at Tencent — one of the world's largest technology companies with a market cap exceeding $400 billion — recently left the company and decided to switch careers entirely, moving into insurance.

Her reasoning? 'AI can replace what I do now, so there is no point continuing.' This perspective, while understandable, reveals a fundamental misunderstanding of where AI actually stands in the technology landscape.

Yes, large language models like GPT-4, Claude 3.5, and Gemini can write code, debug software, and automate many traditional engineering tasks. In the narrow domain of conventional software development, AI is indeed becoming remarkably capable.

But step outside that narrow domain and the picture changes dramatically. In mixed reality environments, AI remains primitive. In brain-computer interface applications — interpreting neural signals for tasks like mind-controlled typing or mental image recognition — AI is not just limited, it is often barely functional. These are precisely the areas where human expertise is most valuable and least replaceable.

Spatial Computing and BCI: The Next iPhone Moment

Apple's launch of Vision Pro at $3,499 in early 2024 signaled that spatial computing has entered its commercial phase. Meta continues to push its Quest line with the Quest 3 priced at $499. Meanwhile, companies like Neuralink, Synchron, and NextMind (acquired by Snap for a reported $100+ million) are advancing brain-computer interfaces from laboratory curiosities toward consumer applications.

The convergence of these technologies represents what many industry observers call the 'next iPhone moment' — a platform shift as significant as the transition from desktop to mobile that began in 2007.

Here is what makes this moment unique for product managers:

• AI is not yet dominant in spatial computing, meaning human product thinking and design intuition remain critical
• MR headsets have not achieved mass adoption, creating a greenfield opportunity for PMs who enter now
• BCI technology requires entirely new interaction paradigms that cannot be copy-pasted from mobile app design
• Spatial interfaces demand rethinking everything from navigation to information architecture
• Cross-disciplinary knowledge spanning neuroscience, 3D design, and AI is required — a combination no single AI tool can replicate

Teams are already building practical BCI applications. One group working across international locations — connected through spatial computing tools that enable remote collaboration as if team members were in the same room — has achieved functional prototypes for mind-controlled typing and mental image recognition. These are not science fiction concepts; they are working systems being developed today.

Western Markets Show Surprising AI Adoption Gaps

One counterintuitive finding from cross-market observation is that AI tool adoption among professionals in Western markets remains lower than expected. Despite having unrestricted access to ChatGPT, Claude, Midjourney, and other leading AI platforms, many advertising designers, product managers, and creative professionals in cities like Sydney have minimal AI integration in their workflows.

This is paradoxical. Professionals in markets with the easiest access to AI tools are often the slowest to adopt them deeply. Several factors explain this gap:

• Comfort with existing workflows reduces urgency to experiment with new tools
• Lack of competitive pressure in local markets where peers are equally slow to adopt
• Misunderstanding of AI capabilities — viewing tools as novelties rather than productivity multipliers
• No structured incentive from employers to integrate AI into daily work

Compare this to markets in East Asia, where competitive pressure drives rapid AI adoption even when access requires workarounds. The lesson for product managers is clear: access to technology is not the same as fluency with technology.

Why Side Projects Are the Ultimate Career Insurance

This brings us to the core argument: every serious product manager needs a side project, and ideally one that operates outside their employer's technology stack.

A side project in frontier technology — whether it is building a simple BCI application, experimenting with spatial computing interfaces on Quest 3, or developing AI agents for emerging platforms — accomplishes several things simultaneously:

• Breaks the walled garden effect by forcing exposure to technologies your employer does not prioritize
• Builds transferable skills in areas where demand will surge as platforms mature
• Creates a professional network outside your company's ecosystem, connecting you with founders, researchers, and builders in adjacent fields
• Provides ground truth about where AI is genuinely capable versus where it falls short — knowledge that cannot be obtained from reading blog posts
• Generates career optionality so that when the next platform shift arrives, you are positioned as an early expert rather than a late learner

The product managers who thrived during the mobile revolution were not the ones who waited for their employers to assign them to mobile projects. They were the ones who built apps on nights and weekends in 2008 and 2009, before the App Store became a $100 billion ecosystem.

The same pattern is repeating now with spatial computing and BCI.

The Clock Is Ticking on the Early-Mover Window

The current moment in spatial computing and BCI resembles the smartphone ecosystem around 2008 — the hardware exists but has not reached mass adoption, the software ecosystem is nascent, and the dominant design patterns have not yet been established.

Apple is expected to release a more affordable Vision Pro successor within the next 18-24 months. Meta's Quest platform continues to grow, with an installed base reportedly exceeding 20 million units. Neuralink received FDA approval for human trials in 2023 and continues advancing its implantable BCI technology.

For product managers, the implication is straightforward. The window to build expertise and establish credibility in these domains is open now, but it will not stay open indefinitely. Once spatial computing reaches its 'iPhone 4' moment — the inflection point where mainstream adoption accelerates — the opportunity to be an early expert will have passed.

What This Means for Your Career Strategy

Product managers should take 3 concrete steps immediately:

First, allocate 5-10 hours per week to a side project involving frontier technology. This does not require quitting your job or taking a pay cut. It requires intentional time allocation.

Second, build cross-disciplinary connections. The most valuable PMs in the spatial computing era will be those who can bridge neuroscience, 3D interaction design, AI engineering, and product strategy. Start attending meetups, joining Discord communities, and collaborating with people outside your current professional circle.

Third, resist the narrative that AI replaces everything. The Tencent engineer who left for insurance made a career decision based on an incomplete understanding of the technology landscape. AI is transforming conventional software development, yes. But it is simultaneously creating massive new domains where human judgment, creativity, and product intuition are more important than ever.

The best product managers have always been the ones who see around corners. In 2025, the corner worth seeing around leads to spatial computing, brain-computer interfaces, and the entirely new product categories they will create. Your side project is how you start looking.