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.Chapters00:00 Intro01:16 What engineering looked like at Microsoft before ChatGPT03:08 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 hand06:08 Why teams are flattening08:26 Why managers need to get back to writing code11:51 How the management layer actually changes14:07 What happens to PMs and designers16:38 Why everyone becomes a builder now20:07 How to actually learn agentic engineering22:42 Finding new tools on X before anyone else23:54 AI adoption is showing up in performance reviews25:45 Building a culture that shares tools daily27:40 The AI productivity paradox, explained29:35 Interviewing with agents instead of against them31:00 Why LeetCode is dead and fundamentals aren't34:11 Who wins and who loses from here35:36 Codex vs Claude Code: what he actually uses36:06 What harness engineering really means38:21 Evals and benchmarks that matter39:59 Desktop apps, Devin, and running agents in parallel43:30 Remote environments and working in monorepos44:34 Skills, plugins, and hooks47:57 Parallel worktrees and staying focused50:42 Agent teams vs subagents53:06 The Finch mission and wrap up