---
title: "Web apps and internal portals · Polargate"
description: "Internal portals, back office apps and operating systems built on Supabase, with row level security, roles, audit logs and Microsoft single sign on."
url: https://polargate.ai/services/build/web-apps-and-portals
locale: en
publisher: POLARGATE S.L.
---
Build // Your operations, out of the spreadsheet and into a real application.

# Web apps and internal portals

Internal portals, back office apps and operating systems built on Supabase, with row level security, roles, audit logs and Microsoft single sign on. Fixed price for a first phase, senior led from discovery to launch.

In short
Polargate builds internal web applications and back office portals for mid-market companies: the operations board, the supplier portal, the tool that today lives in a shared spreadsheet. Each one runs on its own Supabase and Postgres project with row level security, roles, an immutable audit log and Microsoft single sign on. A first phase is fixed price, from 12,000 EUR, and is delivered senior led.

## What it is

An internal web application for the work your company actually runs on: the operations board, the back office, the client or supplier portal, the tool that today lives in a shared Excel and a chain of emails. Polargate builds it as a real application on Postgres, with named users, roles, permissions and a record of who changed what. It runs in the browser on any device, and it can be wrapped as an iOS and Android app when the work happens away from a desk.

## How we do it

We start from your process, not from a template. In the Discovery Sprint we read the spreadsheets, the procedure documents and the email threads where the work is coordinated, and we turn them into a data model, a role map and a written scope for a first phase. Then we build. Security lives in the database: row level security enabled and forced on every table, roles as a Postgres enum checked by a function, sensitive fields such as commercial margin masked by role through a view, and an immutable audit log written by a trigger with an admin only viewer. People sign in through Microsoft Entra ID with the account they already have, or by email with a hardened password flow on your own domain. Every screen ships with its loading, empty and error states, keyboard access and 44 pixel touch targets. Before anything is handed over, the build goes through repeated adversarial audits: on the operating system we built for a hotel refurbishment contractor, one round produced 59 confirmed findings across bugs, security, interface and accessibility, all fixed before delivery.

## What you get

A first phase in production with the modules that carry the most operational weight, running on your own Supabase project and your own repository, with no vendor lock in. You keep the schema, the migrations, the source code and the keys. Business day email alerts, file and photo upload, notifications, and an admin area for the people who govern the system. And a roadmap for the phases after this one, priced separately, so nobody signs a blank cheque.

## What it costs

A first phase is fixed price, from 12,000 EUR, and typically lands between 12,000 and 25,000 EUR depending on the number of modules and integrations. It can be paid in six to ten monthly instalments by direct debit. The Discovery Sprint that precedes it is also fixed price, from 4,900 EUR, and half of it is credited against the build if it starts within 60 days. After launch, a Care retainer from 850 EUR per month covers senior maintenance and evolution.

What you get

- Data model built from your real spreadsheets, procedure maps and email threads, with an entity diagram you approve before we write code
- Row level security enabled and forced on every table, roles as a Postgres enum checked by a database function, sensitive fields masked by role through a view
- Immutable audit log written by a database trigger (who, what, when) with an admin only audit viewer
- Microsoft Entra ID single sign on, or email sign in with a hardened reset flow sent from your own domain
- Operational modules such as planning calendar, tasks by department, checklists, incidents with photos, material reception, suppliers and people
- Business day email alerts from scheduled jobs, plus file and photo storage and an in-app notification centre
- Mobile first interface with loading, empty and error states, keyboard access, focus management and WCAG AA contrast
- Handover of your own Supabase project, repository and hosting account, including schema, migrations, source code and keys
Engagement
Timeline
Discovery Sprint of about two weeks, then a first testable version roughly one month after development starts. A complete first phase is around eight effective weeks of work, which usually spans three to five calendar months depending on your review and decision cycles.

Team
Two people, and neither of them sells. Pedro Ciordia, founder and CTO of Polargate, runs the discovery, the data model and the architecture, and stays on the project until launch. Specialists from the Polargate network join for specific pieces such as brand design or native app publishing. No juniors learning on your budget.

Price
From 12,000 EUR fixed for a first phase, typically 12,000 to 25,000 EUR, payable in six to ten monthly instalments. Discovery Sprint from 4,900 EUR, half credited against the build if it starts within 60 days. Care from 850 EUR per month after launch.

Stack

- React
- Vite
- TypeScript
- Tailwind CSS
- shadcn/ui
- Supabase
- PostgreSQL
- Deno
- Microsoft 365
- Microsoft Entra ID
- Resend
- Vercel
- GitHub Actions
- TanStack Query
- Zod
- Vitest
- Capacitor

## Proof

Elite Smart Build

### A custom operating system for Elite Smart Build

Elite Smart Build, a Spanish hotel refurbishment contractor working in more than twenty countries, ran every site on spreadsheets and email. Polargate replaced that with eleven modules on Supabase and React: daily Gantt, role-masked margins, per-department alerts and material reception with automatic incidents.
2026 Read the case

[A custom operating system for Elite Smart Build](https://polargate.ai/work/hotel-refurbishment-operating-system)

FAQ

## Questions, answered

How much does an internal portal or back office app cost? A first phase with Polargate starts at 12,000 EUR fixed and usually lands between 12,000 and 25,000 EUR, depending on how many modules and integrations it carries. The price is closed before work starts, based on the written scope produced in the Discovery Sprint, which is itself fixed from 4,900 EUR with half credited against the build if it starts within 60 days. We do not bill by the hour, and the build can be spread over six to ten monthly instalments.
How long does it take to build an internal web app? Expect a first testable version about a month after development starts, and a complete first phase in roughly eight effective weeks of work, which normally spans three to five calendar months. The calendar time depends mostly on your side: decisions, content and access to the people who know the process. We deploy to production continuously, so your team is using parts of the system long before the phase closes.
Can our employees log in with their Microsoft account? Yes. Polargate connects the portal to Microsoft Entra ID, so people use the corporate account they already have and your own conditional access and offboarding rules apply. We have done this on a corporate employee portal whose directory of more than 10,000 active employees is synced from Microsoft Graph. Where Entra ID is not available, we set up email sign in with a hardened reset flow sent from your own domain.
How do you stop one department from seeing another department's data? Permissions live in the database, not only in the interface. Every table has row level security enabled and forced, roles are a Postgres enum checked by a database function, and sensitive fields such as commercial margin are masked by role through a view. That means data cannot leak by calling the API directly or through a mistake in one screen. A trigger writes every change into an immutable audit log with the user behind it.
Do we own the system, or are we locked into your platform? You own it. The application runs on your own Supabase project, your own repository and your own hosting account, and you receive the schema, the migrations, the source code and the keys. Polargate does not keep your data on a shared platform and charges no licence fee for software built for you. If you stop working with us, the system keeps running and another team can pick it up.

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[Start your project](https://polargate.ai/start) · [Talk to us](https://polargate.ai/start#static-brief-heading)