Describe a situation where you had to make a strategic technical decision (such as choosing between building in-house vs. adopting a third-party service or framework). How did you evaluate trade-offs like cost, time-to-market, technical debt, and long-term scalability, and how did you communicate your recommendation?

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At my last company, I led the decision on whether to build our own feature flag system or adopt a third-party provider. We had a product launch in 3 months and needed safe rollouts across ~5M monthly active users. I pulled together engineering, product, and finance to compare options. Building in-house was 3–4 engineer-months plus ongoing maintenance; the vendor was about $6K/month. I modeled the vendor cost against expected developer time saved and risk reduction, and we estimated we’d break even in ~9 months while shipping the launch 6 weeks faster. The main concern was vendor lock-in, so I designed an abstraction layer to keep our code decoupled. I presented a 2-page tech brief with cost projections, risk analysis, and a 12–18 month roadmap. We went with the vendor and hit the launch date, cutting release-related incidents by about 60%.

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