You bring the vision.
We ship it in four weeks.
An expert AI engineer builds your custom AI products and automations personally, start to finish. Something real in your hands every few days. Live in weeks, not months.
Virtual try-on for your store
Vision AI · mobile app
Build log
FitRoom
Virtual try-on
Live · on the App Store. Something new every few days.
WhatsApp agent that books leads
Workflow · WhatsApp + n8n
Build log
Customer messages
AI qualifies the lead
Hot vs cold
Books the meeting
Calendar
Alerts the team
Slack · #sales
AI notetaker for sales calls
Voice AI · mobile app
Build log
VoiceDesk
Discovery call · 02:14
5 years building AI for startups and Fortune 500 companies. 15+ AI products shipped.
Why Kerto
What you actually get.
01
A senior AI engineer builds it. Not a junior dev.
You get the actual expert: ex-Head of AI, Fortune 500 AI systems, products used by millions. The hard calls are made by someone who has made them before.
02
Design, build, and deploy, all under one roof.
Figma to Kubernetes, owned end to end under one roof. You never get passed between a designer, a dev, and a DevOps contractor, and nothing gets lost between them.
03
A working product in four weeks.
Something new lands in your hands every few days, never a four month black box. You watch it come to life and steer as it does.
04
Fixed price. No retainers. No scope creep.
One number, agreed before any code. Honest scoping means you spend less than you would with a cheaper team that bleeds you over months.
How it works
Three steps to a live product.
Book a scoping session
Pick a time and book. It is the whole commitment to begin, and it means every call is with someone who is serious.
Get your scope, price, and Loom
You get a written scope, a fixed price, a timeline, and a personal walkthrough video. Yours to keep, whether or not you build with us.
We build and ship
We design, build, and deploy. Something new lands every few days, and your product is live in four weeks. Fixed price, no retainer, no scope creep.
One fixed price for the build, agreed before a line of code. Never a monthly retainer, never scope creep.
Book a scoping sessionWhat we build
Custom AI products
Personalized AI workflows
One expert, two lanes. Whether you are launching a product or taking the busywork off your team, it is the same expert leading the build.
Products
For founders
Apps and MVPs you put in front of users and investors.
Finch
AI analyst · online
Built before: CheckFit (try-on), WarrenAI (Investing.com).
Automations
For owners
Internal tools that take the repetitive work off your team.
Do you deliver to Austin?
Can I get a quote for 50 units?
Gmail
New lead from the website form
Slack
Built before: BloomChat (SME analytics), support automation.
The honest comparison
Same price.
Completely different outcome.
Another agency probably quoted you the same number. Here is what the same money actually buys.
Proof
Real builds.
Real numbers.
Across Airstream, 10xStudio AI, Stochastic AI, and Investing.com. Real builds with real numbers.
WarrenAI
Investing.com
A chatbot that answers complex investing questions in plain English across 70,000 financial instruments.
BloomChat
MSP analytics
An assistant that answers business questions across QuickBooks, SharePoint, and more, with citations.
CheckFit
Co-founded
A virtual try-on app that previews how outfits look on you from a few selfies.
Airstream
Thor Industries (Fortune 500)
A support assistant trained on 60GB of decades-old manuals, deduped and indexed.
Support automation
MakingWeb
A ticket classifier and reply drafter layered onto their existing workflow.
xFinance
Stochastic
A finance LLM trained for under $1,000 that beat BloombergGPT on key benchmarks.
Sarthak Langde
Founder, Kerto
The AI expert
Meet your partner.
Hi, I'm Sarthak. When you work with Kerto, you work with me directly, start to finish. Here is why that is the safest call you can make.
Dual MSc in AI, KTH Stockholm and TU Berlin.
Your model and architecture decisions are made by someone who studied this for years, not someone who learned to call an API last year.
Head of Engineering, then Head of AI.
I have run both the product and the technical side, so nothing gets lost in the gap between them.
Built Fortune 500 AI systems at production scale.
Your AI is built to be depended on by a real business, not just demoed once and abandoned.
8 startups, products used by millions.
Your product gets scoped like a startup that has to win, not a slow corporate IT project.
Full stack, Figma to Kubernetes.
Design, build, and ship all happen under one roof, to my standard. No handoffs, nothing lost in translation.
Which sounds like you?
Find the problem. See the fix.
Pick what sounds like your situation, and watch how Kerto would build the answer.
Founder brief
I want nurses matched to shifts based on qualifications, location, and how tired they are.
Kerto interpretation
Sarthak
Fatigue scoring is the hardest part. Here is how we would approach it.
In their words
What it's like to work with me.
I had the pleasure of working with Sarthak and his team on an MVP to validate a business idea. I’m extremely happy with the experience. Sarthak knows how to ship fast and is proactive in identifying and clearly explaining the trade-offs behind technical decisions. Overall, working with him felt almost like working with a cofounder.
Simone Lini
Head of BD & PM @ Google Travel
His work ethic, attention to detail, and bias for action makes him stand out from the rest as he brings in expertise in technical architecting and project management. Would highly recommend working with him on ML/AI, and end to end product development.
Skanda Bhat
Technical Lead @ Razor Network
Sarthak is a thorough purist and never hacks around to get things done. He believes in going deep and doing things the right way. And, many of his insights during code reviews has made many engineers better.
Siddarthan SP
Staff Backend Engineer @ Automattic
The scoping session
Get your build mapped.
Start to finish.
One paid session turns your idea into a written scope, a fixed price, and a personal walkthrough video. It is yours to keep, whether or not you build with us. Here is exactly what you walk away with:
Included
A written scope
Exactly what gets built. No vague “AI magic.”
A fixed price
One number for the build, agreed upfront. No ranges, no surprises.
A timeline
When each piece ships, week by week.
A personal Loom walkthrough
Me explaining your build, plainly. Yours to keep.
A proper discovery phase usually runs into the thousands.
Yours to keep, whether or not you build with us.
Then, if you build: most projects are $5,000 - $20,000, fixed and agreed before a line of code. Never a retainer.
“Incredibly flexible, and he always came through with practical solutions.”
You bring the vision.
We ship it.
One small step to a clear plan and a fixed price.