Karumi (YC F25)

Agentic product demos

[Karumi (YC F25) @KarumiAI]

Demo now!

[Y Combinator @ycombinator]

Karumi (@karumihq) is an AI demo agent that makes product demos scalable — it talks, clicks, and personalizes every walkthrough, 24/7.

[Karumi (YC F25) @KarumiAI]

https://t.co/WE0xnqoic6

[Karumi (YC F25) @KarumiAI]

🚨 We're partnering with @EnzoVentures  for our Madrid FDE hiring day.

Founders, operators, and VCs in the room with you. And very few spots left.

Pressure-test your build, get real feedback, and meet the people backing the next wave of AI companies, all in one day.

The deal is the same: build an AI agent, demo it live, and strong candidates walk out with an offer that day.

📍 Madrid
📅 June 26
🎟️ Almost full, application required

If you want in, now's the time. Applications close June 21.

Think you can get hired in a day? 🚀

Link to apply 👇

[Karumi (YC F25) @KarumiAI]

We've detected something AI can't do. And never will.

Not running a demo. Not qualifying a lead. Not working a Saturday night. It does all of that.

This is the one thing it'll never manage:

New chairs arrived. The reclining kind. Pablo, Mario and Itziar ran a thorough, afternoon-long evaluation. 

The agent handles the demos. The deep, important work of leaning all the way back on a Tuesday is ours.

Some things you still need a body for.

What's the most human perk AI will never take from you?

[Karumi (YC F25) @KarumiAI]

500+ demos.
50+ hours of live demo time.

All in the last 2 to 3 months. Not run by the team. Run by the agent.

That's Salesforge's CEO, @franksondors , on the numbers since they handed their demos to the agent. They run it under their own brand and call it the Agent Frank demo. Underneath, it's Karumi.

Every one is the real product, live on the call. No recording, no clickable tour, no avatar reading a script.

They didn't add headcount to hit that. They added an agent.

How many demos is your team running a month? Drop the number below.

[Karumi (YC F25) @KarumiAI]

We don't have a billboard. So we made one.

Okay, it's a mockup. We haven't bought highway space. Yet.

But if we ever do, that's the line up there. Word for word.

A year ago, San Francisco was covered in "Stop Hiring Humans" billboards. We weren't fans. No "the robots are coming," no fear-mongering.

The one thing we fix: the buyer who asks for a demo and gets left waiting.

Our agent jumps on the call and runs it live, the second they're ready.

Simple enough to fit on a billboard.

[Karumi (YC F25) @KarumiAI]

We build an AI that runs B2B demos on its own.

So we handed the team that built it some axes.

Mario missed. Then missed again. Then kept missing, calm as a man debugging in prod while the target sat there untouched.

Itziar shrugged and buried one dead center like she'd done it a thousand times.

Building a demo agent and throwing an axe: very different skill sets. We're extremely good at one of them.

The product runs on that one.

Who on your team would put us to shame?

[Karumi (YC F25) @KarumiAI]

The 1995 side of this picture is a museum. The beige box, sure. But also the sales process right under it.

We modernized everything except how we sell.

The computer went from a beige tube to the screen on the right. The demo? Still a rep, a scheduled call, and a five-step whiteboard run by hand. Pure Jurassic Park.

Hardware evolved 30 years. The sales motion barely moved.

Karumi is the 2026 version: an AI agent that runs the live demo the second a buyer wants it.

The beige box had its run. So did the manual demo.

Try it yourself, link below. No booking, no waiting, just a live demo of the real product.

[Karumi (YC F25) @KarumiAI]

The engineer who writes the code for our AI demo agent spent the weekend as MVP of a national-league promotion game.

Itziar is a founding engineer at Karumi. She also plays for CB Pozuelo, who just earned promotion to LF2 in Spain.

Decisive game, highest stakes. Top-rated player on the court, team of the matchday.

We talk a lot about the agent. Less about the people building it.

She writes the code that makes the demos work, and on weekends she wins promotions as MVP.

That's the bar here.

[Karumi (YC F25) @KarumiAI]

@shiyam_kashfiq what do you mean cut competitor window? the agent send meetings to sales

[Karumi (YC F25) @KarumiAI]

Every B2B SaaS demo is supposed to go like this:

Buyer → requests a demo → gets the demo → buys.

Reality… looks more like this:

Buyer → requests a demo, then waits for someone to reply
Buyer → finally gets a slot… for next Thursday
Buyer → takes a competitor's demo in the meantime

Just… gone. Before your rep even said hi.

So we fixed that.

With an AI agent that joins the call and runs the full demo the second a buyer asks. Real product, live, any hour.

No form-to-meeting gap. No "let's find a time."

[Karumi (YC F25) @KarumiAI]

Salesforge now runs 500+ live product demos a month, without adding a single rep.

Before, inbound was a manual grind: 350 to 400 demos, run by people, by hand. They handed those to the agent.

500+ demos in the last 2 to 3 months. 50+ hours of live demo time, on the real product, at any hour. No new headcount.

@franksondors 's own read: for an AI-first team, bringing this in was the obvious move. The only thing he'd change is doing it sooner.

How many demos is your team running a month? Drop the number below.

[Karumi (YC F25) @KarumiAI]

@justgrm Here is explained, you can read it all! https://t.co/wTQPrLCJT6

[Karumi (YC F25) @KarumiAI]

635 out of 1,000 B2B companies never replied to a demo request.

Not slowly. Never.

A team at RevenueHero submitted demo requests to 1,000 B2B SaaS companies and tracked what actually happened. Of the 365 that bothered to reply, the average response time was 1 day, 5 hours, and 17 minutes.

Here's how all 1,000 handled a buyer raising their hand:

- 172 replied instantly (under 2 minutes)
- 31 within the hour
- 109 within a day (averaging ~10 hours)
- 41 within a week (averaging ~3.5 days)
- 12 took over a week (one group averaged 27 days)
- 635 never responded at all

And that's just the reply. Getting in was its own obstacle course: the average demo form had 7 fields, one had 21, and only 113 of the 1,000 sites had any scheduling tool installed. So even buyers ready to book often had nowhere to do it.

Sit with what that means. Requesting a demo is the highest-intent signal a buyer ever sends you. They are telling you they want to buy. The most common response, by a wide margin, is silence. The second is a day-plus wait, by which point most of them are gone. And the first vendor to respond usually takes the deal.

So most of that pipeline isn't lost to a better product or a lower price. It's lost in the gap between "I want to see it" and "someone got back to me."

We built Karumi to close that gap to zero.

The second a buyer asks for a demo, our agent joins the call, day or night, and runs it live. Not a recorded walkthrough. Not a clickable tour. Real software, real clicks, the actual product reacting in real time, adapting to whatever they ask. No SDR triage. No "let's find time next week." No 21-field form.

3,000+ demos delivered this way so far.

If your demo funnel has a queue, this is what removing it looks like.

See it run on yours: https://t.co/jRWMsKa5Af

[Jose Quezada @joseplusai]

While your sales team is still manually hunting down prospect emails and job titles, your competitors are using #AI to build perfect lead lists in seconds.

The gap between AI-driven sales teams and everyone else is widening fast. A new report from @KarumiAI
shows you what you are missing. 👇

[Karumi (YC F25) @KarumiAI]

@joseplusai Thank you very much!

[Karumi (YC F25) @KarumiAI]

@1tagupta @ycombinator happy to talk!

[Karumi (YC F25) @KarumiAI]

Your product video on your landing is being ignored. And it took you hours to make it.

Hours of scripting. Recording. Re-editing because the UI changed.

All so visitors could bounce in 8 seconds and skip the part they were interested about. So we shipped something better.

The new AI inside Karumi (YC F25) turns your product video into a conversation.

→ Learns your product
→ Demos it live, the way your visitors want to see it

Okay, but, do I need to update it?

No! The agent picks up on product changes and self-improves from every interaction. No re-recordings. No outdated videos.

And if you don't like something, just tell it what to change in natural language.

Too good to be true? We are opening limited spots to try our autopilot mode.

DM to check it out!

[Karumi (YC F25) @KarumiAI]

https://t.co/hAOqlezHkn

[Karumi (YC F25) @KarumiAI]

Karumi team dinning inside a sauna.

[Toni Lopez @tonilopezmr]

The Hackerazo SF hacker house is getting together tonight.

@rebolthq (YC W25) and @KarumiAI (YC F25) were born under the same roof.

[Karumi (YC F25) @KarumiAI]

@paulodoestech @tonilopezmr @rebolthq it was, we dinner in a sauna