Stop Googling when to replace your air filter.

AI handles the research, sets the reminders, and syncs them with the calendar and apps you already use.

AI for real homes

Your plan is ready.

No manual research required.

The right manual, read.Useful guidance matched to what you own.

The care, planned.Clear timing, steps, supplies, and safety.

What comes next, remembered.Trusted reminders before small work becomes expensive.

Join Apple waitlist Join Android waitlist

Built for the systems that keep a home running Clear guidance, not gadget control Every AI result stays editable A real product, not a concept

Why we build

For people who take ownership.

Thomas Rizzie and Javier Garcia started Sweat Tech with a simple belief: people who choose hard things, carry real responsibility, and intend to win deserve serious tools. We build for people who expect more from themselves—and from the technology they trust.

Castellan began with the responsibility closest to us: our own homes. Even as engineers building complex systems and pushing AI to its practical limits, we were still handed buried manuals, invisible maintenance, and expensive surprises. The problem was not effort. Our homes had no operating system.

We built Castellan to give capable homeowners the leverage to stay ahead.

Meet the founders and read the full story

Castellan founders Javier Garcia and Thomas Rizzie — **Javier Garcia & Thomas Rizzie**AI engineers, homeowners, and co-founders of Castellan

How we build

Turn complexity into leverage.

Castellan applies engineering discipline and modern AI to research, organize, and remember the care a home needs. It turns scattered evidence into useful context and clear next actions—so taking ownership does not mean carrying every detail yourself.

Understand what you own

Start with the exact appliance, system, or important item you own—not a generic checklist.

Do the research

Turn manuals, photos, receipts, and details into useful context and care you can act on.

Keep you ahead

Surface what matters next with clear reasoning—without guilt, false urgency, or noisy alerts.

Join us early

Bring the same standard home.

Choose your platform. We’ll send one email when Castellan is ready—no launch spam.

iPhone and iPad waitlist

Be first to know when Castellan launches.

One email when Castellan is ready on the App Store. No launch spam.

Android waitlist

Get the Android launch email.

One email when Castellan is ready for Android. No launch spam.

The product today

The maintenance plan your home should have come with.

Castellan investigates the item, builds a personalized maintenance plan, and remembers the details and decisions that make future care easier. AI does the work. You stay in control.

Start with whatever evidence you have.

A photo, a sentence about the item, or a saved PDF is enough to begin. You can fill in the rest when you have it.

Photo-assisted intake
Descriptions and manual entry
PDF documents and records

Castellan first-item screen with photo, description, and PDF intake options

Castellan figures out what you own—and what it needs.

Castellan enriches the record and builds recurring care. You review the result and change anything that does not fit your home.

Editable item identity and records
Recurring care plans
Warranty, ownership, and replacement details

Castellan first-item result showing an identified dishwasher, saved sources, and prioritized maintenance

Your whole home stays in view.

Today, Upcoming, Pending, and Activity turn scattered maintenance into one calm system.

Care organized by what needs attention
Upcoming work stays visible
Home items and history in one place

Castellan home screen showing Today, Scheduled, Pending, Activity, and saved home items

Know what to do—and why it matters.

Each plan explains the timing, effort, value, preparation, and safety behind the work. Then you decide what happens next.

Clear next care and effort
Guided steps, supplies, and safety
Complete, skip, or remind later

Castellan maintenance plan showing next care, effort, why it matters, and completion options

Context that compounds

Castellan doesn’t just build the plan. It remembers it.

Details, decisions, and completed care stay attached to the item—so knowledge stops disappearing into drawers, inboxes, and memory.

Remembered context

Everything important stays with the item.

Identity, care, supplies, documents, notes, and ownership details remain editable and easy to find.

Castellan dishwasher details with care, supplies, activity, make, and model information

Calm accountability

What you handled stays handled.

Completed care, skipped work, and supporting evidence form a practical history—not a guilt-driven backlog.

Castellan activity history showing completed dishwasher care and the original item creation record

The builders behind Castellan

We build the tools we need to win.

Thomas brings air-traffic, aerospace, and defense systems thinking. Javier brings modern AI/ML research and production agentic systems. Sweat Tech is where those disciplines become serious products for people who take ownership.

Read our story

Founder Pricing

Join early. Keep Founder Pricing.

We built Castellan for our own homes. The first homeowners who join us can keep Founder Pricing while their subscription remains active.

AI-assisted items and personalized maintenance plans
Documents, notes, warranties, and history
Reminders and calendar feed

^$4.99per month

or save with annual

$39.99per year

Join the waitlistPlanned launch pricing. Continuous active subscription required to preserve the Founder price. We’ll confirm availability by email.

Questions, answered

Know exactly what you’re joining.

Still deciding? Email support@mycastellan.com.

Why did you build Castellan?

We founded Sweat Tech to build serious software for people who take ownership. Castellan applies that mission to our own homes: engineering discipline and modern AI replace scattered research, invisible maintenance, and memory with a system that helps homeowners stay ahead.

How much does Castellan cost?

Founder Pricing is planned at $4.99 per month or $39.99 per year when Castellan launches. Join the waitlist and we’ll email you when it is ready.

Is Castellan available now?

Not publicly yet. The iPhone and iPad app is release-ready but does not have a public App Store page. Join the Apple or Android waitlist and we’ll send one email when your version is ready.

What kinds of information can I add?

You can start an item with text, a photo, or a PDF. You can also add and edit item details, warranties, ownership records, documents, notes, expected replacement information, and a display image.

Can I correct what the AI finds?

Yes. AI-assisted results are a starting point, not a locked record. You stay in control and can edit your item information and care details.

Does Castellan replace a qualified professional?

No. Castellan organizes information and offers practical maintenance guidance, but it is not a substitute for manufacturer instructions or licensed professional advice. Stop and get expert help when a task involves safety, code, gas, high voltage, structural work, or anything outside your experience.

For people who take ownership

Win at home.

Join us on Castellan

Be there at launch

Choose your platform and join the journey.

Built for our homes. Ready for yours. We’ll email you when Castellan is ready.