Walk Me Through a Build-or-Buy Decision You Drove Where a Large Amount of Money Was at Stake
Behavioral and LeadershipTechnical JudgmentAsked atPrincipalUpdated
They're checking whether you can price a build-or-buy decision over its full life. Strong answers compare total cost of ownership, weigh strategic fit and lock-in, involve finance and procurement, and revisit the call with real numbers.
Rubric by Level
Junior
- Chose between writing a utility and using a library, with a reason.
- Checked the library's license, maintenance, and fit.
- Names what you'd check next time.
Mid
- Evaluated a few open source or paid options for a team need.
- Compared them on cost, integration effort, and maintenance.
- Wrote up a recommendation the team could act on.
Senior
- Led a build-or-buy decision for your team with a cost comparison.
- Counted the engineering time to integrate and operate along with the price.
- Assessed later whether the choice held up.
Principal
- Drove a decision with a large budget impact and company-level strategic weight.
- Framed it by what differentiates the company, and kept engineering focused there.
- Partnered with finance, legal, and executives, and negotiated terms from the analysis.
- Revisited the decision with actual costs and shared the results.
Red Flags
- Chose to build because the team wanted to.
- Counted license cost and ignored the engineering time to integrate and run it.
- Never checked the estimate against what actually happened.
Follow-Ups to Expect
- What would have made you reverse the decision?
- How did you plan for leaving the vendor, if it came to that?
- What did the finance team push back on?
A Story Shape That Holds Up
The Need
The capability, and why the decision was large.
The Analysis
Total cost, strategic fit, and lock-in for each option.
The Decision
Who was involved, what you chose, and the terms you secured.
The Real Numbers
What it actually cost, compared to the estimate.