Kelly Zhang

About

I was CTO at three mobile-first companies: a consumer social app (48M users at peak), a developer tools platform (acquired by GitHub for $110M), and a B2B mobile analytics SaaS. I've been fractional since 2021 and work primarily with companies that have iOS/Android at the core of their product — not as an afterthought. My particular edge is in the technical and organisational patterns that let small mobile teams ship fast without accumulating the kind of platform debt that requires a 6-month rewrite.

Experience highlights

At the developer tools company (acquired by GitHub for $110M), I led the mobile and API platform teams through the acquisition process and the subsequent 18-month integration into GitHub's infrastructure. Managing a technical acquisition integration while simultaneously shipping product is a uniquely demanding context that very few engineers have navigated twice — I have.

Before that, I was CTO at a consumer social app that reached 48M monthly active users. The engineering challenge at that scale is not building features — it's making sure your infrastructure budget doesn't grow faster than your revenue. I reduced our AWS spend by $1.2M annually through a data pipeline and cache architecture redesign that took four engineers 10 weeks.

My fractional practice is almost entirely mobile-native companies. The common problem: founding teams hire great iOS and Android engineers but no one with the architectural experience to avoid the platform fragmentation that accumulates over the first 3 years. I've saved three companies from the "full rewrite" decision by identifying and resolving the 5–10 foundational decisions that were causing the cascade of maintenance problems.

Expertise

Past companies

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