Mistake 1: Building a Platform When You Need a Tool
The most expensive mistake executives make is building too much. A CEO with a powerful vision and deep industry knowledge naturally thinks in terms of platforms, ecosystems, and comprehensive solutions. But platforms take years and millions of dollars to build. The executive side project that tries to be a platform on day one almost always runs out of budget, patience, or both before reaching product-market fit.
A CTO at a healthcare analytics company wanted to build a "comprehensive patient engagement platform" as a side project. The initial spec included a patient portal, appointment scheduling, automated follow-ups, satisfaction surveys, telehealth integration, and a provider dashboard. The estimated build cost was $200K and the timeline was nine months. Three months and $80K in, the project had produced a partially functional portal that did none of the six things well. The CTO pulled the plug.
The fix is brutally simple: build a tool, not a platform. Pick the single highest-value feature and build that. If the CTO had launched with only automated post-visit follow-ups—a feature that takes six weeks to build and solves a concrete, measurable problem—he would have had a working product, paying customers, and revenue to fund the next feature. This is why structured development approaches like the MVP Sprint force scope discipline from day one.
Mistake 2: Using Your Internal Engineering Team
It seems logical. You have a talented engineering team. They know your industry. They could probably knock out an MVP in a few sprints. But using your internal team for a side project is one of the fastest ways to damage both the side project and your core business simultaneously.
The problems compound quickly. Your engineers are already committed to a product roadmap with quarterly objectives. Adding a side project—even as a "low priority"—creates invisible context-switching costs. Studies consistently show that engineers lose 20-30% of their productivity when splitting attention between two codebases. Your core product suffers. Your side project gets leftover attention, leading to mediocre execution. And when your board or leadership team discovers that company resources are being used for a personal venture, the conversation is deeply uncomfortable.
The solution is complete separation. Engage an external development partner from the start. Companies like Sizzle exist specifically for this scenario—executives who need high-quality development without touching their internal teams. The external team operates on its own infrastructure, its own sprint cadence, and its own communication channels. Your CTO never needs to know unless you want them to.
Mistake 3: Skipping Validation Because You Are the Expert
Executives are domain experts, and that expertise creates a dangerous blind spot: the assumption that because you understand the problem deeply, you already know the solution people will pay for. This is the expertise trap, and it kills side projects that should have succeeded.
A COO in the logistics industry was certain that fleet managers needed a better route optimization tool. She had heard complaints about existing solutions for years. She invested $60K in a sophisticated algorithm-driven platform, launched it, and discovered that fleet managers did not actually want better route optimization. They wanted simpler driver communication tools. The pain she had been hearing about was a symptom, not the root cause. Two weeks of structured customer interviews would have uncovered this disconnect and redirected the investment toward the actual need.
Validation does not mean you doubt your expertise. It means you verify that your expertise points toward the right solution, not just the right problem. Even the most experienced executives benefit from a disciplined two-week validation sprint before committing to a build. The cost of validation is trivial compared to the cost of building the wrong product.
Mistake 4: Neglecting the Business Model Until After Launch
Technical founders obsess over features. Executive founders often obsess over market positioning. But both sometimes neglect the business model—the specific mechanics of how the product generates revenue—until after the MVP is built. By then, the product architecture may not support the optimal pricing model, and retrofitting is expensive.
A CEO built a beautifully designed project management tool for creative agencies. The product worked well and early users loved it. But the CEO had not thought carefully about pricing until launch week. He defaulted to a per-seat model at $15 per user per month. Creative agencies, with their mix of full-time and freelance staff, hated per-seat pricing. They wanted project-based pricing, but the entire user management and billing infrastructure was built around seats. Restructuring the billing system cost an additional $25K and delayed revenue by two months.
Define your business model before you write a line of code. Pricing strategy, billing frequency, the unit of value (per seat, per project, per transaction, flat rate), free trial structure, and upgrade triggers should all be decided during the scoping phase. When you work with a venture studio like Sizzle Ventures, business model design is part of the upfront strategy work, ensuring the technical architecture supports the revenue model from day one.
Ready to Build Your Side Project?
Executives across every industry are turning side project ideas into real products—without pulling a single engineer off their core team. The key is working with a partner who understands both the technical execution and the strategic context of building alongside a day job.
Sizzle Ventures helps executives go from idea to launched product in as little as 90 days. Our MVP Sprint is built specifically for leaders who need speed without sacrificing quality—and without touching their internal dev team.
Ready to explore what's possible? Start a conversation with Sizzle about bringing your side project to life.