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Brief

Software engineer & engineering leader in Singapore. Senior Staff @ Meta, ex-Googler. Building and writing about AI agents.

I'm Ziwei Peng — online, most people know me as pzw. I'm a software engineer and engineering leader based in Singapore.

By day I work on large-scale systems and the teams that build them. I'm currently a Senior Staff Software Engineer at Meta, after roughly a decade at Google — most recently as a Staff SWE / engineering manager on Google Pay — with stops at ByteDance and Sea along the way. I've spent about equal time as an individual contributor and leading teams, across infrastructure, payments, growth, social, and communications.

In my own time I'm deep in AI agents: building small projects, writing my own skills, agents, and harnesses, and writing up what I learn — the shift from prompt to context to harness engineering, the filesystem as agent infrastructure, spec-driven development with agent swarms, and where this is all heading.

This site is part personal brand, part experiment. The chat is grounded in my writing and a public knowledge base, so you can ask it about my work and ideas — or just read the blog and skim my career.

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