Roc & Zig: A Compiler Rewrite Story • Anjana Vakil & Richard Feldman • GOTO 2026

This interview was recorded for GOTO Unscripted. #GOTOcon #GOTOunscripted https://gotopia.tech Richard Feldman - Software Engineer at Zed Industries & Author of “Elm in Action” @rtfeldman Anjana Vakil - Freelance Software Engineer & Developer Educator @vakila Check out more here: https://gotopia.tech/articles/442 RESOURCES Richard https://bsky.app/profile/rtfeldman.bsky.social https://twitter.com/rtfeldman https://www.linkedin.com/in/rtfeldman https://github.com/rtfeldman Anjana https://bsky.app/profile/anjana.dev https://github.com/vakila https://www.linkedin.com/in/anjanavakil https://anjana.dev Links https://zed.dev https://adventofcode.com https://www.roc-lang.org https://youtu.be/X2e_zZa5OnE https://youtu.be/01v_H7PpHXc https://youtu.be/9LoZ4MvAAe8 https://youtu.be/jIZpKpLCOiU https://youtu.be/6EdFiISk22k https://youtu.be/0kI-as3K4Zo https://youtu.be/aWZFRk-w3ng https://youtu.be/Pg3UeB-5FdA https://youtu.be/Tml94je2edk https://youtu.be/YXrb-DqsBNU https://youtu.be/7oIs4kNH65Y https://youtu.be/6mLYZF97oaU DESCRIPTION Richard Feldman and Anjana Vakil trace the Roc programming language's ambitious ground-up compiler rewrite — from Rust to Zig — which happened to coincide almost exactly with the year AI coding assistants went from useful to transformative. Richard describes how AI's role shifted over just 12 months: from mechanical test-porting grunt work, where it was reliable but limited, to genuine architectural collaboration on harder problems. The key insight is that guardrails don't live in prompts ("never do this" gets ignored constantly), they live in the code itself — invariants and automated feedback loops that catch the AI when it strays, rather than instructions it will cheerfully disregard. The conversation widens into what the AI era means for software quality and trust. Both are wary of the coming wave of AI-generated "slop" — buggy, mediocre software produced at scale — but Richard makes the counterintuitive case that competitive pressure might actually force quality up: if everything is slop, the products that aren't will stand out hard. Anjana draws a parallel to consumer electronics brand trust: just like we pay a premium for the USB-C cable we know won't cause a fire, developers and users will increasingly gravitate toward names and communities they can vouch for. The open source contribution model, they agree, needs new systems to navigate this — and Roc v1, due before the end of 2026, will be a test case. TIMECODES 00:00 Intro 01:46 Roc's origins: Elm beyond the browser 02:57 Why rewrite the compiler in Zig? 04:41 AI in March '25 vs. March '26 17:19 The hidden cost of AI coding tools on open source 23:36 Will "slop" make software better? 31:55 Outro RECOMMENDED BOOKS Richard Feldman • Elm in Action • https://amzn.to/387kujI Dean Bocker • Don't Panic! I'm A Professional Zig Programmer • https://amzn.to/3ljKT8d Tim McNamara • Rust in Action • https://amzn.to/3ux2R9u David Drysdal • Effective Rust • https://amzn.to/4dAjbdX Eric Normand • Grokking Simplicity • https://amzn.to/3gz7o3C https://bsky.app/profile/gotocon.com https://twitter.com/GOTOcon https://www.linkedin.com/company/goto- https://www.instagram.com/goto_con https://www.facebook.com/GOTOConferences #Roclang #Ziglang #Rustlang #Elmlang #FunctionalProgramming #SoftwareEngineering #Programming #TodayInTech #AnjanaVakil #RichardFeldman #GOTO CHANNEL MEMBERSHIP BONUS Join this channel to get early access to videos & other perks: https://www.youtube.com/channel/UCs_tLP3AiwYKwdUHpltJPuA/join Looking for a unique learning experience? Attend the next GOTO conference near you! Get your ticket at https://gotopia.tech Sign up for updates and specials at https://gotopia.tech/newsletter SUBSCRIBE TO OUR CHANNEL - new videos posted almost daily. https://www.youtube.com/user/GotoConferences/?sub_confirmation=1