Why start a new company, on Rails and AI, today. SF Ruby Conf 2026, Irina Nazarova

1. WHY START A NEW COMPANY ON RAILS, AND AI, TODAY Irina Nazarova · CEO, Evil Martians SF Ruby 2026 ▶▶ 1 1 PLAYER PLAYER 2 2 PLAYERS PLAYERS
3. SF SF RUBY RUBY X03 X03 Ruby’s best years might be ahead of us. Garry Tan Y Combinator
4. EIGHT BUILDERS ON RAILS SF SF RUBY RUBY WORLD WORLD 1-1 1-1 MEET Carmine Paolino THE Cole Robertson X04 X04 FOUNDERS Avinash Joshi Kieran Klaassen Chat with Work AI assistant for teams Rebulk Rail and bulkmaterial operations Cactus AI answering calls for the trades Cora at Every AI email assistant Miles Woodroffe Brian Reath Paul Cothenet Brian Mascarenhas Mindful Chef Healthy recipe boxes Tern Software for travel advisors Patch Carbon credits and related commodities Reset Earned wage access
5. SF SF RUBY RUBY X05 X05 LOVES: FAST START If you want to start a startup today, I couldn’t recommend anything more than building on Rails. Cole Robertson Rebulk
6. SF SF RUBY RUBY X06 X06 LOVES: FAST START If I started again today: Rails, from scratch. You get so much from it already. Kieran Klaassen Cora at Every
7. SF SF RUBY RUBY X07 X07 LOVES: CONVENTIONS One of my worst nightmares: a room with five senior engineers who all have different opinions, expecting to reach a conclusion. Brian Reath
8. SF SF RUBY RUBY X08 X08 LOVES: WEB PRIMITIVES Rails has the web primitives nailed down in a way no other framework or language has. Cole Robertson Rebulk
9. SF SF RUBY RUBY X09 X09 LOVES: VANILLA STACK Single EC2 instance, Postgres, Kamal, Solid Queue, Solid Cache. As vanilla Rails as it can get. Avinash Joshi Cactus
10. SF SF RUBY RUBY X10 X10 LOVES: RUNS ANYWHERE I have Rails running on a rural farm in Upstate New York, on a tiny Jetson computer, talking through Starlink to the cloud. Cole Robertson Rebulk
11. SF SF RUBY RUBY X11 X11 LOVES: CALM FRONT END I haven’t had a conversation about the front-end stack in four years. I don’t care. I build a JavaScript controller. It works. Paul Cothenet
12. SF SF RUBY RUBY X12 X12 LOVES: HOTWIRE Hotwire is so much easier to handle than React. Carmine Paolino Chat with Work
13. SF SF RUBY RUBY X13 X13 LOVES: HOTWIRE I can’t think of the last time I thought: if only we weren’t using Hotwire, we could do this. Brian Reath
14. SF SF RUBY RUBY X14 X14 LOVES: INERTIA RAILS I now have Inertia and React with a real Rails back end, and I love it. This is not a toy project. If you haven’t tried Inertia with Rails, try it. It’s honestly very good. Kieran Klaassen Cora at Every
15. SF SF RUBY RUBY X15 X15 LOVES: INERTIA RAILS I start the new projects at our company on the Inertia Rails stack. That’s my go-to. Cole Robertson Rebulk
16. SF SF RUBY RUBY X16 X16 SECRET ITEM INERTIA.JS ON RAILS The Official Guide BRIAN KNOLES G COMIN SVYATOSLAV SOON KRYUKOV
17. SF SF RUBY RUBY X17 X17 LOVES: NOTHING MISSING It tells you a lot about Rails and Ruby that I can’t even think of anything that is a problem. Miles Woodroffe
18. SF SF RUBY RUBY X18 X18 LOVES: AI IN RUBY Building AI features, I thought we’d have to use Python. Honestly, we haven’t had to. Paul Cothenet
19. SF SF RUBY RUBY X19 X19 LOVES: AI CHEAT CODE It’s still a cheat code to build AI features on Ruby, and it’s underestimated. Paul Cothenet
20. SF SF RUBY RUBY X20 X20 LOVES: AGENT-FRIENDLY LLMs are so good at Rails codebases. Way fewer footguns, and it knows exactly where to put things. Cole Robertson Rebulk
21. SF SF RUBY RUBY X21 X21 LOVES: AGENT-FRIENDLY Agents write code, agents review code, and because it’s very standard Rails, it just works like a dream. Miles Woodroffe
22. SF SF RUBY RUBY X22 X22 LOVES: PRODUCT FOCUS You don’t want AI to stumble over these things. You want it to stumble over your product thinking. Kieran Klaassen Cora at Every
23. SF SF RUBY RUBY X23 X23 LOVES: ONE-PERSON TEAM One person, me: iOS, Android, web, competing with Gmail and Superhuman. This is an insane world. Kieran Klaassen Cora at Every
24. SF SF RUBY RUBY X24 X24 LOVES: COMMUNITY Ruby people want to work with other Ruby people. Once you found them, closing them wasn’t as hard. Brian Mascarenhas
25. SF SF RUBY RUBY X25 X25 LOVES: EXPRESSIVE Why did it take Matz to write the most expressive English? Still no one’s done better, 30 years later. Miles Woodroffe
26. SF SF RUBY RUBY X26 X26 LOVES: READABLE The big win for Ruby with agents: it’s a lot easier to read. You can’t read Java. You have to construct it in your head. Miles Woodroffe
27. SF SF RUBY RUBY X27 X27 LOVES: READABLE The readability of Rails has become helpful in an AI-first world, where agents write almost all of the code. It feels true. Brian Mascarenhas
28. SF SF RUBY RUBY X28 X28 LOVES: READABLE Coding agents are my exoskeleton. I read more code than ever. Which better language to read than Ruby? Carmine Paolino Chat with Work
29. SF SF RUBY RUBY X29 X29 WANTS: COMPONENTS COMPONENTS AND UI BUILT Every time Vercel ships a new library, I wish we had it for Ruby. We have Tailwind, and nothing else. HTML-aware ERB, default in Rails 8.2. ReActionView builds on it. MARCO ROTH Write <Card /> in ERB. Slots, <Async> . Experimental. 88 components, 9 themes, built for agents too. ERB, Turbo, Stimulus. MATT SOLT DESIGN ENGINEERS That tooling isn’t there, so the best design engineers don’t want to touch Ruby. Herb components Poetry UI DESIGN SYSTEM I’d love a complete component library with a design system on top, not one maintained by a single person. YEAR Herb is in Rails A UI STANDARD React has standard design components. Rails has many options and no standard, and I don’t want to test them all. THIS ? Figma to ViewComponent or Herb Component? Nobody has built it yet.
30. SF SF RUBY RUBY X30 X30 WANTS: RICHER HOTWIRE RICHER Turbo’s primitives are simple, and that’s the problem. Building a real product with them is complicated, which is anti-Rails. IN REVIEW HOTWIRE HOTWIRE DOCS Hotwire has been around since 2021, and the docs are still thin. Hotwire needs a lot more documentation. NOW rails/rails #58617 A new official Rails guide: Using Hotwire with Rails. Turbo, Turbo Streams over Action Cable, Stimulus. By Ayush Newatia, for the Rails Foundation docs project.
31. SF SF RUBY RUBY X31 X31 WANTS: I/O-HEAVY CONCURRENCY FIBERS FOR BUILT AI apps make a huge number of slow IO calls. Rails needs first-class async to handle them. YEAR fibers: 100 in queue.yml. Async jobs, no Redis. CARMINE PAOLINO RubyLLM 2.0 Model fallbacks and safe stream retries, across 17 providers. Action Cable on fibers Merged into Rails main. Ships in the next Rails. ASYNC JOBS I love the Solid stack and SQLite. I just want async jobs on it without adding Redis. THIS Solid Queue fibers Most Rubyists think threads are fine. LLM calls are exactly the case for fibers. ASYNC IO AI VLADIMIR DEMENTYEV Talk: When Rails Met Fibers AI STREAMING Shopify moved Sidekick from Puma to Falcon. Streaming, errors, fallbacks: everyone is solving these by themselves, in their own apps. SAMUEL WILLIAMS
32. SF SF RUBY RUBY X32 X32 WANTS: LESS MEMORY BUILT THIS YEAR Action Cable → AnyCable A FOUNDER Hosting Rails takes a lot of compute, mostly memory. VLADIMIR DEMENTYEV ★ Action Cable holds every WebSocket in your Ruby workers. AnyCable moves them to Go. Ractors on Kino Rails in one process: nearly 7× less memory than Puma workers. Shopify’s experiment Where does the memory go? ? A tool or an APM recipe that names the gem, the endpoint or the connection.
33. SF SF RUBY RUBY X33 X33 WANTS: LLM TRACING BUILT ★ A FOUNDER I checked eight or nine LLM tracing vendors. None had a Ruby SDK, so I built my own on OpenTelemetry. SDKS THIS YEAR OpenTelemetry Ruby Official OpenAI and Anthropic instrumentation. Braintrust Ruby SDK ★ Official. Auto-traces RubyLLM, OpenAI, Anthropic. github.com/braintrustdata/braintrust-sdkruby Send them anywhere ★ ? Datadog and Langfuse read OpenTelemetry GenAI traces. supports OpenTelemetry. RubyLLM SDKs? Sentry: WIP, open PRs.
34. SF SF RUBY RUBY X34 X34 WANTS: SAFE PROD ACCESS FOR AGENTS BUILT bin/rails query A FOUNDER To troubleshoot production, my agent writes console snippets, I run them by hand, and paste the output back. I want it to look without being able to change anything. ★ Read-only queries for agents, JSON out. By Lewis Buckley, merged April 15. github.com/rails/rails/pull/ 57156 Isolator VLADIMIR DEMENTYEV Stops jobs, emails and HTTP calls inside a transaction, so a sandboxed console can’t reach out. github.com/palkan/isolator
35. SF SF RUBY RUBY X35 X35 SO FOUNDERS LOVE RAILS. AND AND THEY TOLD US WHAT TO BUILD NEXT. AND THEY THEY TOLD TOLD US US WHAT WHAT TO TO BUILD BUILD NEXT. NEXT.
36. SF SF RUBY RUBY X36 X36 THREE YEARS OF ASKS ASKED ASKED →→ BUILT BUILT UI components 24 25 26 An LLM library 24 25 26 Types for AI 24 25 26 Hotwire docs 24 25 26 Durable agent jobs 24 25 26 A path to 100 ms 24 25 26 24 25 26 → Herb, RubyUI, Poetry UI → Rails guide: Using Hotwire, in review → RubyLLM, Active Agent → Rails 8.1 continuations, AJDC ASKED → → Types do not affect agentic coding → Spinel, Roundhouse BUILT Fibers for AI I/O Safe prod access Congratulations, Ruby community! Official SDKs 24 React or Vue on Rails 24 25 26 A community 24 25 26 25 26 → OpenAI, Anthropic, MCP → Inertia Rails, Turbo Mount → Meetups, and this conference → Falcon, Solid Queue and Action Cable on fibers LLM tracing → OpenTelemetry, Braintrust Rails ↔ Python sync → River: Postgres queue, Ruby and Python clients 24 25 26 → bin/rails query 24 25 26 24 25 26 Less memory → AnyCable, Ractors, Roundhouse + Spinel 24 25 26
37. SF SF RUBY RUBY WORLD WORLD 2-1 2-1 PART 2 WHAT’S OUR JOB IN THE AI REVOLUTION? X37 X37
38. CONNECT WITH THE PRESENT SF SF RUBY RUBY LEARN FROM WORLD WORLD 2-2 2-2 EXPERIENCE SHARE THE PRESENT. BUILD WORKS FOR YOU How to test, eval and benchmark: tools, and also opinions and hypotheses about what works. Wins and losses, in big teams and small. Real experiences over sales pitches. UNDERSTAND WHAT X38 X38 THE FUTURE. THAT’S WHY YOU’RE HERE.
39. SF SF RUBY RUBY WORLD WORLD 2-3 2-3 Ruby’s best years might be ahead of us. Garry Tan Y Combinator X39 X39
40. TYPICAL NON-ENGINEER IN A RUBY COMPANY SF SF RUBY RUBY WORLD WORLD 2-4 2-4 X40 X40 More Ruby code than ever Rails apps used by 50 people Contributed to Rails and Herb NOO IT’S ME. A B NON-ENGINEER.
41. SF SF RUBY RUBY WORLD WORLD 2-5 2-5 RAILS FOR HUMANS X41 X41
42. RAILS IS THE BEST AGENTIC FRAMEWORK FOR HUMANS SF SF RUBY RUBY NO DECISIONS Convention over configuration. WORLD WORLD 2-6 2-6 NO PLUMBING Batteries included. X42 X42 CODE I CAN READ It reads like English. Especially the tests.
43. LET’S WELCOME HUMANS SF SF RUBY RUBY WORLD WORLD 2-7 2-7 X43 X43 Build Build the the missing missing tooling. tooling. Make Make them them feel feel welcome. welcome. HELP IN YOUR COMPANY HELP Help non-engineers build tools on Rails: for themselves, then their team, then the product. THEM CONTRIBUTE Missing tooling, a safe boundary, review agents, a harness. More on that later. TAKE TAKE CARE OF THEM
44. STEP 1: INVITE THEM TO RAILS GIRLS SF SF RUBY RUBY WORLD WORLD 2-8 2-8 RAILS RAILS GIRLS GIRLS Thursday, Nov 12 Mux HQ 10:00–4:00 ORGANIZER Dalma Boros luma.com/railsgirls2026 INVITE A TEAMMATE. COME MENTOR. X44 X44
45. SF SF RUBY RUBY WORLD WORLD 3-1 3-1 X45 X45 BUT WHAT’S THE ENGINEER’S ROLE IN THIS FEAST OF CODE GEN? IT’S CHANGING. LEARN NEW SKILLS, AND CHANGE.
46. SF SF RUBY RUBY WORLD WORLD 3-2 3-2 X46 X46 P1 CHOOSE CHOOSE YOUR FIGHTER CHOOSE YOUR YOUR FIGHTER FIGHTER Product engineer Loves talking to the product’s end users Has intrusive thoughts about new features and changes Asks why TRAIT PASSION
47. ASKS WHY SF SF RUBY RUBY WORLD WORLD 3-3 3-3 The why, not just the what. Those people are going to succeed wildly. Brian Mascarenhas X47 X47
48. SF SF RUBY RUBY WORLD WORLD 3-4 3-4 X48 X48 P1 CHOOSE CHOOSE YOUR FIGHTER CHOOSE YOUR YOUR FIGHTER FIGHTER High-risk engineer In charge of the riskiest parts of the product Payouts, billing, security TRAIT RESPONSIBILITY
49. REVIEW BY RISK SF SF RUBY RUBY WORLD WORLD 3-5 3-5 X49 X49 Payments Payments ·· background background jobs jobs ·· critical-path critical-path latency latency ·· security security Button spacing Check the result in a review app Payment rules VS VS An engineer builds and reviews this
50. SF SF RUBY RUBY WORLD WORLD 3-6 3-6 X50 X50 P1 CHOOSE CHOOSE YOUR FIGHTER CHOOSE YOUR YOUR FIGHTER FIGHTER Platformplatform Agentic engineerengineer Owns In charge the of agents’ developer environment: productivity and quality context, tools, permissions Ownsevals Runs tooling on and whatquality agents produce Builds team Turns primitives knowledge and abstractions into skills and to make things simpler guardrails TRAIT CURIOSITY
51. SF SF RUBY RUBY WORLD WORLD 3-7 3-7 WHAT MAKES AN X51 X51 ENGINEER ENGINEERS DON’T COPY-PASTE. Yes, Yes, Stack Stack Overflow. Overflow. ItIt proves proves the the point: point: copy-pasting copy-pasting makes makes us us self-conscious. self-conscious. SAME WITH AI RECIPES: EVALUATE THEM. TEST THEM.
52. RUN THE QUALITY LOOP SF SF RUBY RUBY WORLD WORLD 3-8 3-8 Define what quality means for us, and how to track it 1 ↑ Yes: win. Next metric. 4 → X52 X52 Observe traces and quality metrics 2 No: back to 3 → Track: did quality improve? ↓ ↓ ← Investigate degradations. Build preventive tooling. Ship. 3
53. KEEP BUILDING BETTER ABSTRACTIONS SF SF RUBY RUBY WORLD WORLD 3-9 3-9 From From our our AI AI evals: evals: agents agents fail fail when when they they hand-roll hand-roll what what the the framework framework already already solved. solved. LIVE UPDATES Action Cable apps passed. Hand-rolled polling flooded the server or lagged two seconds. SSRF GUARD Only the agent that reused the app’s private-network guard blocked private addresses. MIGRATIONS 4 of 4 hand-wrote the migration instead of running the generator. 3 made it irreversible. Agents Agents on on Rails Rails evals, evals, October October 2026: 2026: live live quiz quiz greenfield greenfield app, app, Campfire Campfire bots, bots, Forem Forem Active Active Storage. Storage. X53 X53
54. SF SF RUBY RUBY WORLD WORLD 3-10 3-10 X54 X54 RUBYONRAILS.ORG/AI AGENTS ON RAILS Commissioned Commissioned by by the the Rails Rails Foundation. Foundation. Built Built by by Evil Evil Martians. Martians. FOU N DATION AMANDA 46 TASKS REDMINE · IN 3 FOREM HIDDEN STAGES · PERINO WRITEBOOK CONSUL TESTS · DEMOCRACY ACCURACY · FIZZY + 2 SPEED · CAMPFIRE APPS · BUILT TOKENS · · MASTODON FROM COST SCRATCH
55. SF SF RUBY RUBY WORLD WORLD 3-11 3-11 X55 X55 HIRE MARTIANS BUT NICOLAS CAMILA VICTORIA VOVA FIRST, ANTON SVYATOSLAV L. TALK TO US! ALEKSANDR IRINA TRAVIS ALEXANDER AMANDA KIRILL ANTON S.
56. SF SF RUBY RUBY WORLD WORLD 3-12 3-12 X56 X56 OUR JOB IS TO CONNECT TO THE PRESENT Learn everyone’s lived and frontier experiences Share techniques to test what works for you CONNECT TO THE PRESENT TO PRAGMATICALLY BUILD THE FUTURE.
57. SF SF RUBY RUBY X57 X57 GARRY’S ASK Keep building. Start the company. Ship the side project. And teach the next person why beautiful code still matters, even when a machine helps write it. Garry Tan Y Combinator
58. SF SF RUBY RUBY X58 X58 IN A TIME OF DISRUPTION, WE VALUE COMMUNITY.
59. SF SF RUBY RUBY X59 X59 FIND WHERE THINGS YOUR WAY ARE Talks: right here, on the main stage. Conversation groups: Joe Henderson Lab, behind registration. LUNCH Plan lunch on Slack #conference-2026-lunch-plans. sfruby.com/lunch JOBS 119 open positions at 56 Ruby companies. 8 are entry-level. sfruby.com/jobs YOUR MATCHES Make new Ruby friends: meet your matches, see email!
60. SF SF RUBY RUBY NEW IN THE X60 X60 CLOUDS GAME RUBY GOODIES Valuable Valuable items items from from Ruby Ruby companies. companies. Buy Buy them them with with the the coins coins and and hearts hearts you you earn earn in in the the game, game, and and pick pick them them up up right right here at the conf. clouds.sfruby.com THE BIG PRIZE Actual open source Evil Martians will build something cool for you. Subject to limits.
61. SF SF RUBY RUBY X61 X61 THANK YOU, SPONSORS ORGANIZERS ORGANIZERS PICKAXE PICKAXE RUBY RUBY COFFEE COFFEE SPEAKER SPEAKER DINNER DINNER COMMUNITY COMMUNITY PASSPORT PASSPORT EMERALD EMERALD TRAVEL TRAVEL MEDIA MEDIA
62. SF SF RUBY RUBY WORLD WORLD 3-13 3-13 NEW X62 X62 GAME+ SF RUBY CONFERENCE 2027 SEPTEMBER SEPTEMBER 9 9 · · SFJAZZ SFJAZZ ► TICKETS GO ON SALE ★★ NOW $199 luma.com/sfrubyconf2027 COMMUNITY COMMUNITY DAY DAY SEPTEMBER SEPTEMBER 10 10 ►► SPONSOR SPONSOR NOW NOW sfruby.com/sponsor-2027
63. SF SF RUBY RUBY X63 X63 THANK YOU! ► ► ► ► ► evilmartians.com anycable.io irina@evilmartians.com x.com/inazarova linkedin.com/in/nonconstant