Blastoff Rails 2026 · Albuquerque

Startups on Rails

2026 Report · Irina Nazarova · Evil Martians · SF Ruby

opening keynote

Do you agree?

“Rails is a framework
for CRUD apps.”

Irina Nazarova

CEO at Evil Martians
Co-founder at AnyCable
Org of SF Ruby Community

This year, five of them

Meet the founders.

Cole
Rebulk

Carmine
Ruby LLM

Kieran
Cora

Avinash
Cactus

Andy
Finta

Cole Robertson

Rebulk · YC S25

JavaScript → Rails

Cameras + computer vision measuring bulk inventory — Rails on a tiny edge computer, on a farm, over Starlink.

runs on a small VPS · YC S25

Let's start with Cole. He was a JavaScript developer, Node, Next, the whole stack, until one Christmas his CTO rewrote the entire product into Rails, alone, in two weeks. Cole thought he'd lost his mind. He was wrong. The team grew from three developers to over a hundred, people who'd never written Ruby, shipping in months, because every Rails app is laid out the same way. [CLICK] Now he runs Rebulk, and he's put Rails somewhere it supposedly can't go: a little box out in a field, doing computer vision over Starlink. If it holds up there, it holds up anywhere.

Cole Robertson

Rebulk

If you want to start a startup today, I couldn't recommend anything more than Rails.

Cole Robertson

Rebulk

Ruby on Rails has the web primitives nailed down in a way no other framework or language has.

Carmine Paolino

Chat with Work · creator of Ruby LLM

Python · data science → Ruby

AI that answers across everything your company knows — built on Ruby LLM, his own library.

Ruby LLM 8M+ downloads · reads more code solo than a 15-person team · pursuing SOC 2

Carmine Paolino

Chat with Work

Rails got it right all along. It just wasn't understood.

Carmine Paolino

Chat with Work

I read more code than ever. And which better language than Ruby to read?

Kieran Klaassen

Cora

Musician → Rails

An AI email client, native on iPhone and Android via Inertia + Ruby Native.

Cora power user Mike Krieger · compound-engineering 70k★ (Google, Amazon) · keynotes tomorrow 9:30

Kieran Klaassen

Cora

Web, iOS, Android. One person. Me. Competing with Gmail and Superhuman. Insane world we live in.

Kieran Klaassen

Cora

Rails makes the decisions for me. You don't want AI to stumble on those — you want it to stumble on your product thinking.

Avinash Joshi

Cactus · YC S25

Django → Rails

Voice AI that answers the phone for home-service businesses — Rails monolith, Solid trifecta, Ruby LLM.

$7M seed · YC S25 · “plan mode made me faster”

Avinash Joshi

Cactus

I built the same app twice, once in Django, once in Rails, and instantly knew I'd stop building with Python.

Andy Wang

Finta · YC W23

Finance · non-technical → Ruby

Interactive, simple accounting for founders and startups.

Andy Wang

Finta

We're in the business of simplifying. So why not build with a language that simplifies?

Andy Wang

Finta

I ship 80 PRs a day, six months straight. It's crazy.

What this unlocks

Rails is the best stack for non-technical founders working with agents.

What's good · Inertia

Hotwire and Inertia.
You want both.

Try Inertia with Rails — it's honestly very good. A thin wrapper; the heavy stuff stays in React.

Kieran Klaassen · Cora

Every new project, I start on the Inertia + Rails stack. That's my go-to.

Cole Robertson · Rebulk

The other half of the report

What's missing.

Same five founders, one more question: what would make Rails better? Their wishlist. ↓

What's missing · Fibers, through the whole stack

It's all just waiting on the model. I want async first-class in Rails, not something I bolt on.

A Ruby founder · building on Rails today

It's landing: Falcon · fiber-aware Active Record · Action Cable re-architected

Number one, and three of the five named it: real fiber support, the whole way through the stack, Active Record and the drivers included, not just in spots. An AI app is almost pure I/O, and fibers are built for exactly that. As one founder put it: it's all just waiting on the model, I want async first-class, not something I bolt on. [CLICK] And the work is landing: Falcon as the async web server, a fiber-safe Active Record, Matthew Draper pushing query pipelining to keep it non-blocking, and just two weeks ago Vladimir from our team got the new Action Cable architecture merged into Rails core. Hold that thought — it pays off in a few slides.

What's missing · Documentation

Hotwire's been around since 2020. This is the documentation we got?

A Ruby founder · building on Rails today

A fix? Ship the docs as agent skills.

What's missing · Hiring

Our posting said “founding engineer — Ruby.” Seventy percent of applicants had never written Ruby.

A Ruby founder · building on Rails today

Hiring or looking? sfruby.com/jobs

What's missing · Component & design libraries

Every time Vercel ships a component library, I think: I wish I had this for Ruby.

A Ruby founder · building on Rails today

A fix? Inertia brings React's libraries to Rails — inertia-rails.dev

What's missing · the big one · 5 of 5 founders

“Click, wait, cmd-R” is not enough.
Rails can do more.

The front end was the one all five named. It can be live and interactive — Marco Roth is rebuilding it.

Let's jump ahead — an experiment: Rails in your browser, on PGlite. →

But the one every single founder named — all five — was the front end. So let's kill the myth you walked in with: that Rails means CRUD, that you click, you wait, you hit command-R to see what changed. That's over. Kieran set the bar: click a button, wait fifty milliseconds, and you've already lost. [CLICK] So the Rails front end has to feel instant, optimistic, alive — and it can. Marco Roth, who we work with, is rebuilding Hotwire to be genuinely interactive. [CLICK] But let me jump ahead and show you an experiment: a Rails app, and its database, running right inside your browser. I had to find out if it was real.

So I built it myself, standing on years of work from Vladimir and the Martians. Remember Andy, my non-technical founder building Finta, an accounting startup? He asked me how you'd build a Figma-grade spreadsheet on Rails, millions of rows, instant, no spinner. Three people told him Rails is not the way. Let me show you the way. A slice of the database lives right here in the browser. That's a real Postgres, PGlite, and it's running Active Record's own SQL. Editing a column resettles every total, even the median, in under twenty milliseconds, with no network. The write goes to Rails, and Rails stays the one and only write authority: one gesture, one transaction. Then the authoritative rows stream back and the screen settles on the server's numbers. And when the server says no, the change rolls back, and the local copy never lies. The client can be fast because the server is still in charge. And I took it further. That page can be the whole Rails app, the router, Active Record, the views, booted inside the browser tab. The same aggregates action, the same query object, reading two different databases, returns the same answer. That's the same Rails, relocated into the browser.

How it works · an experiment, still early

In the browser tab

Rails on ruby.wasm

via wasmify-rails · Hotwire rendering

PGlite, Postgres in the tab the synced slice · a ClientScope

writes

read-only sync

Electric · WAL

On the server

Rails, sole write authority

one gesture, one transaction

PostgreSQL the source of truth

What you get

Active Record migrations stay in sync
Validations & consistency, same code both sides
No duplicate domain model in TypeScript

Still missing

Per-user auth, end to end: the slice holds only what you may see
Interactive rendering: slot-level diffing (ReActionView)
Bounded, self-evicting sync · offline conflict resolution

PGlite · ElectricSQL · ruby.wasm · palkan/wasmify-rails · on years of work from Vladimir Dementyev & Evil Martians

Here's how it fits together, and it's an experiment, still early. You just saw the writes: they go to Rails, the one authority. The new part is the reads: Electric tails the Postgres write-ahead log and streams a read-only slice down, a named client-scope, so the tab only ever holds what you're allowed to see. And the whole Rails app can boot right there in the browser, compiled with wasmify-rails. Why do this? One app on both sides: your migrations stay in sync, your validations and consistency come for free, and there's no parallel TypeScript model of your domain to maintain. What's still missing is real work: per-user authorization end to end; and to make it truly interactive, slot-level diffing, the ReActionView direction Marco Roth is building, so you re-render one cell, not the page. Plus bounded, self-evicting sync, and offline conflict resolution, the one genuine research problem. It's early.

Don't settle for CRUD.
Keep making new things possible.

whichlang · a benchmark by Chad Fowler

AI agents are handed real coding tasks, never told the language. The tasks are his, not ours. For the product builds: how many picked Ruby?

0 of 210 product builds. Not one.

Now, most of my year wasn't spent talking to founders. It wasn't spent talking to humans at all. It was spent talking to the models. Chad Fowler, who a lot of you know, built a benchmark called whichlang: it hands an AI agent a real coding task, never tells it the language, and counts what it picks. The tasks are his, from the public whichlang repo, not mine, so I can't tilt them. I ran it. Across the product builds, a real B2B SaaS, the exact thing you just watched Rails do, how many picked Ruby? [CLICK] Zero. [CLICK] Zero, out of two hundred and ten product builds. Not once. [CLICK] And it is not about capability, you've seen the capability all morning. So why? Why would they pass on Ruby? I didn't want to just feel bad about it, so I went and checked.

Rage.

DjangoDjango ORM

RailsActive Record

FastAPISQLAlchemy

13k

Nest.jsPrisma

23k

RageActive Record, fiber-aware · Iodine

48k · 2× NestJS · 5× Rails

GET /widgets-orm/42 · req/s, median of 5 Fly performance-16x hosts (16 vCPU · Postgres 17 loopback · 200 conc · oha) · 2026-06-10.
github.com/irinanazarova/small-runtime-bench

Before I got angry, I got curious, so I ran the benchmark myself. Every major stack, head to head, each one fetching a row through the real ORM you'd actually ship. Why does Ruby win here? Async. Threaded Rails blocks a thread on every query; a fiber-based server overlaps them, and an AI app is almost all waiting. [CLICK] Through a real ORM the field clusters low: Django and Rails at eight and nine thousand, FastAPI at thirteen, NestJS at twenty-three. Then Rage. Async Ruby, on Iodine, with a fiber-aware Active Record: forty-eight thousand. Two times NestJS, five times Rails and Django. The fastest stack that still uses a real ORM is Ruby, and you keep Active Record. Raw JavaScript goes faster only by dropping the ORM and hand-mapping every row; real ORM to real ORM, async Ruby wins. A minute ago Rage was what I felt at that zero; here it's the framework that answers it. [CLICK] And here's exactly how I measured it. It's all in the repo, you can run it yourself.

And cheap for an agent to run

Cost for Claude Code to generate a mini-Git across 13 languages — Ruby is the cheapest

Cost for Claude Code to build the same project in 13 languages · Ruby is cheapest. Benchmark by Yusuke Endoh (mame) · dev.to

Ruby is fast and token-efficient.
Why aren't models picking it?

ruby.evilmartians.com

Ruby & Rails LLM Discoverability Scorecard — 92 sites graded on llms.txt, .md docs, sitemaps, crawlers

But here's the thing: this is the most fixable problem in the whole talk. The models didn't pass on Ruby because Ruby is bad, they learned from a web where we stayed quiet. So let's change it, together. Every 'I built it in Rails' post is training data for next year's model. Carmine put it best: increase the blast radius, post it everywhere, something always sticks. And I didn't just complain, I built you a scorecard, and it's right here: ruby-dot-evilmartians-dot-com. [CLICK] Here's what's inside: ninety-two Ruby sites, scored on how the models actually read them, with a fix-list for each. And here's that list, in four layers.

Layer 0

Get into the
training corpus.

Unblock AI crawlers — robots.txt + WAF
Ship sitemaps, server-render

Crawlable 85/92 · Sitemaps 49/92

Layer 1 · ship now

Win the retrieval.

Serve Markdown — content negotiation + .md routes
Make rdoc emit Markdown, for token efficiency

llms.txt 43/92 · .md routes 21/92 · content negotiation 13/92

The case · ship now

Write the “Build X in Rails” comparisons.

Rails vs Next, Django, Laravel — a SaaS, a chat app, a marketplace
Real numbers: lines of code, time to ship, cost to run
A model reaches for what the corpus argues for

Of 12 common product builds, 0 have a solid, numbers-backed case for Rails

Layer 2 · ship now

Make agents fluent
in the gems.

Every gem ships agent tooling — an MCP endpoint or a skill, like a README
Converge one Rails MCP server — introspect gems, schema, routes
Agree a shared Agent Skills convention

shared gem/agent convention none yet · Agent Skills fragmented
A start: github.com/Bakaface/rails-hyperdrive — an MCP server + skills for any Rails app

Layer 3 · the long game

Change the
training default.

Contribute real Rails repos to Multi-SWE-bench
Build an open, idiomatic-Rails dataset

Ruby in Multi-SWE-bench absent · idiomatic-Rails dataset none yet

How we'll know it worked

Let's do this together, and watch that 0 move.

I re-run the benchmark every year. 0 of 210 is the number to beat.

Ruby on Rails is the best stack for agentic software development.

It's up to us to make people and models know.

You walked in thinking Rails is for CRUD apps. Forms, click, wait, refresh. You've seen the receipts: computer vision on a farm over Starlink; an AI that reads everything a company knows; email on web, iOS, and Android from one person; voice AI that answers the phone and books the job; accounting shipping eighty pull requests a day, from someone who isn't an engineer; a spreadsheet running Rails in the browser; and the fastest stack with a real ORM. That is not CRUD. Ruby on Rails is the best stack for agentic software development. [CLICK] And it's only going to get better, because of people like you, the Ruby community, passionate and driven to build together and make new, exciting things possible. The models haven't caught up yet. It's up to us to make people, and the models, know.

sfruby.com evilmartians.com x.com/inazarova irina@evilmartians.com

November 10–12, 2026

SF Jazz · San Francisco

Keynote

Garry Tan

President & CEO, Y Combinator

Rails + Startups = ♥

And one more thing. [CLICK] We're announcing the second San Francisco Ruby Conference: November tenth to twelfth, at SF Jazz. [CLICK] And the keynote is Garry Tan, President and CEO of Y Combinator, who built YC's own software on Rails. Sit with that: the President of Y Combinator, opening a Ruby conference. Ruby isn't the past, it's where the next great companies get built. So go build one, and come to San Francisco in November to show us. [CLICK] Rails, startups, and Y Combinator, coming together, because they belong. Rails plus startups equals love.

Let's GOOOOO

Startups on Rails

“Rails is a frameworkfor CRUD apps.”

Irina Nazarova

Meet the founders.

Rails is the best stack for non-technical founders working with agents.

Hotwire and Inertia.You want both.

What's missing.

“Click, wait, cmd-R” is not enough.Rails can do more.

Don't settle for CRUD.Keep making new things possible.

Rage.

Get into thetraining corpus.

Win the retrieval.

Write the “Build X in Rails” comparisons.

Make agents fluentin the gems.

Change thetraining default.

Let's do this together, and watch that 0 move.

Ruby on Rails is the best stack for agentic software development.

“Rails is a framework
for CRUD apps.”

Hotwire and Inertia.
You want both.

“Click, wait, cmd-R” is not enough.
Rails can do more.

Don't settle for CRUD.
Keep making new things possible.

Get into the
training corpus.

Make agents fluent
in the gems.

Change the
training default.