Build or buy an internal developer platform: build the total-cost comparison.
Compare total cost of ownership like for like. Buying still needs a platform team, building never ends at launch, and a later launch delays benefit. On illustrative figures for 300 engineers over three years, buying costs 1,595k against 2,775k to build, and building wins at steady state only above about 900 engineers.
Answer
Short answer
A total cost of ownership comparison only works when both options deliver the same scope over the same horizon. Buying an internal developer platform still needs people to build golden paths and own the data, and building one never shrinks to zero people after launch. Under the illustrative assumptions below, for 300 engineers over three years, buying costs 1,595k and building 2,775k once delayed benefit is priced. Building only wins at steady state above roughly 900 engineers, so the case for building rests on non-cost factors, not on the spreadsheet.
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Likely follow-ups
- Which single assumption in your table would you test first, and how would you test it in a month?
- The vendor offers a three-year price lock for a larger upfront commitment. How does that change the comparison?
- Headcount is forecast to triple in three years. Redo the break-even and tell me what you would decide now.
- How would you present this table to a CFO who distrusts the time-saved line?
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