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Custom software and apps, from a studio that runs its own products.

Studio Northstar builds custom software from The Hague: new products, internal tools and apps. We build with ARCS, our agentic platform, and run our own products ourselves, so we know what happens after delivery.

Talk about your project

We reply within three working days.

What we build

Four kinds of software. Where we have built one ourselves, you can try it.

  • A new product

    From an idea to a product people use. Plens, Attentico and FamAway started that way.

    See Plens

  • An internal tool

    Software for your own team, built around how you work. We start from your long-term goal and write down the agreements first.

  • An app for the phone

    Plens gives rain advice for your whole route. FamAway puts one trip plan on every phone in the family, and it works without signal.

    See FamAway

  • A closed environment for your organisation

    The Academy is a closed learning environment: one licence per organisation, passwordless sign-in and progress per participant.

    See the Academy

Four stages, from plan to product

Each stage has a page of its own. In every stage, ARCS does the work and a different model checks it.

  1. Research

    We write down your goal, the context and the quality bar, so every result can be checked against them.

    Research

  2. Strategy and data

    Build patterns, sources and quality rules live in a shared knowledge base, so no project starts from scratch.

    Strategy and data

  3. Build

    We build in bounded tasks. One model does a task, a different one checks the result and the correction.

    Build

  4. Operate

    We bring our own products to market and run them, so we build with what comes after delivery in mind.

    Operate

Where your data stays

We choose per task where the work runs and record that choice: on our own machines, or with a model from an outside AI provider. When material may not leave the building, the work runs on Northstar One, our own machines and models on a private network.

About Northstar One

Built and run by us

Three of our own products, built with ARCS and run by us. You can use them today.

  • Plens

    Route-aware rain advice that compares nearby departure times and tells cyclists, runners and walkers when a small shift makes the trip drier.

    See Plens

  • Forenta

    Turns an idea, plan or existing codebase into a reviewed product route, with the assumptions and risks made explicit first.

    See Forenta

  • FamAway

    One trip, on everyone's phone, working offline: planning, bookings, real travel times per leg and a map that keeps working without signal.

    See FamAway

Questions we get.

What does custom software cost?

That depends on what you want built, for whom and which systems it has to work with, so we name no amount here. After the first conversation we write down your goal and what counts as done in a brief. We reply to your request within three working days.

How long does it take to develop an app?

That depends on what the app has to do, so we name no fixed term here. In the brief we write down what has to be done at delivery, and the planning follows from that, with gates where you decide.

Do you build apps for the phone?

Yes. Plens and FamAway are apps you use on your phone, and FamAway also works without signal. Which form fits your app is decided together and written down in the brief.

What happens after delivery?

What happens after delivery is agreed in the brief: who runs the software, who improves it and how your team takes it over. We run our own products ourselves, so we build with that in mind.

Can you build on existing code?

Yes. We start with a review of what is there: a council from ARCS assesses the code and its risks, and you get the findings with the checks behind them. Then we decide together what to build next.

Tell us what you want to build.

We reply within three working days. After the first conversation we write down your goal and what counts as done in a brief.

Talk about your project

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