The $7.5 Million Hidden Cost of DIY Internal Developer Platforms

Building a custom internal developer platform (IDP) is often framed as a strategic move toward autonomy, but it frequently evolves into a massive, hidden financial commitment. A recent analysis by The New Stack argues that the true cost of a DIY platform is far higher than most executives realize, potentially draining millions in capital and diverting critical engineering talent away from revenue-generating products.

According to the analysis, a fully functional enterprise-grade IDP typically requires a 60-person engineering organization. This workforce is split across seven distinct product teams covering infrastructure, operations, deployment, runtime/middleware, databases, security, and coaching/enablement. Based on a conservative average salary of $125,000 per engineer, the estimated annual payroll for such a team reaches $7.5 million. The report notes that these costs are often obscured from leadership because they are distributed across various engineering cost centers rather than listed as a single platform line item.

The Comparative Advantage of Buying

The debate over "build vs. buy" in platform engineering hinges on where a company's competitive advantage actually lies. Referencing Simon Wardley’s maps and David Ricardo’s theory of comparative advantage, the analysis suggests that infrastructure is increasingly a commodity. When companies build their own "plumbing," they consume scarce engineering capacity that could otherwise be spent on bespoke business logic—the actual applications that differentiate a company in the market.

Abby Bangser, speaking at KubeCon NA 2025, emphasized this distinction, stating, "It’s not about rebuilding what we can purchase that is available on the market. It’s about making sure we spend our time building the things that are bespoke and important for our organization."

The Velocity Gap and ROI

Beyond the initial payroll, companies face a "velocity gap" where commercial vendors typically outpace internal innovation within 12 to 18 months. The New Stack warns that the return on investment (ROI) often evaporates when internal teams struggle to replicate features that vendors ship rapidly. As the author puts it, "The year-three meeting where someone says ‘we need to add the AI services that Vendor X shipped last quarter’ is the meeting where the ROI quietly evaporates."

This efficiency gap is further highlighted by staffing ratios. While a DIY approach requires dozens of engineers, commercial platforms can be operated with significantly fewer staff. The analysis cites examples of ratios as low as four operations staff for 300 application teams, or 16 operations staff supporting 6,500 developers.

The Long-term Burden

Many enterprises fall into the trap of starting with a "weekend project" platform that eventually becomes a permanent and expensive maintenance burden. The report suggests that engineers may be incentivized to build rather than buy due to "résumé-driven development," where creating a custom platform is viewed as a more impressive achievement for promotion packets than implementing a third-party tool.

Ultimately, the analysis concludes that there are "no personal pan pizzas" when it comes to building a platform; you cannot build a "small" version that avoids the long-term overhead of enterprise maintenance. Companies must decide if their core value is in the platform itself or the software they deliver to their customers.