Siddharth Nanda - Microsoft Engineer Reveals how Engineering Will Never be the Same Again

"Software has been solved." Most of the best engineers I know have landed on this exact conclusion. Last week I sat down with Siddharth Nanda, who went from writing every line of code by hand at Microsoft and Atlassian to shipping 30,000 lines a week with 0% of it written by him. He's now at Finch, a startup that's raised $20M+ to automate admin work at personal injury law firms, where 100% of the code he writes comes from agents. He's seen big tech before AI and a startup fully running on it, so he has a pretty unique read on where this all goes. We get into why he hasn't written a line of code in 8 months, why middle management is getting hit hardest by the layoffs, and why the productivity studies saying companies are getting slower are right, but only for companies with the wrong people. We also dig into the tooling itself: Codex vs Claude Code, what harness engineering actually is, running Devin agents in parallel, and why the cost of producing code is approaching zero, and what that means for the kind of engineer who thrives from here. If you're building with agents, this one's full of hard-won takes from someone doing it every day. Chapters 00:00 Intro 01:16 What engineering looked like at Microsoft before ChatGPT 03:08 The first AI tools inside big tech (and how gated they were) 05:17 Shipping 30,000 lines a week, none of it written by hand 06:08 Why teams are flattening 08:26 Why managers need to get back to writing code 11:51 How the management layer actually changes 14:07 What happens to PMs and designers 16:38 Why everyone becomes a builder now 20:07 How to actually learn agentic engineering 22:42 Finding new tools on X before anyone else 23:54 AI adoption is showing up in performance reviews 25:45 Building a culture that shares tools daily 27:40 The AI productivity paradox, explained 29:35 Interviewing with agents instead of against them 31:00 Why LeetCode is dead and fundamentals aren't 34:11 Who wins and who loses from here 35:36 Codex vs Claude Code: what he actually uses 36:06 What harness engineering really means 38:21 Evals and benchmarks that matter 39:59 Desktop apps, Devin, and running agents in parallel 43:30 Remote environments and working in monorepos 44:34 Skills, plugins, and hooks 47:57 Parallel worktrees and staying focused 50:42 Agent teams vs subagents 53:06 The Finch mission and wrap up