selfprivacy.org/content/en/docs/Theory/architecture.md

---
title: "Project architecture"
linkTitle: "Architecture"
weight: 5
date: 2022-01-09
description: >
  How the project is organized and how it works.
---

Yes, you could use kubernetes. But why when immutability is ensured by NixOS?

**User app:** [Flutter](https://flutter.dev/)/[Dart](https://dart.dev/) was chosen because of the speed and smoothness of the UI and cross-platform.

**Server side (backend):** [NixOS](https://nixos.org/) + [Python](https://www.python.org/). NixOS was chosen because of its reproducibility, python because of its versatility and popularity.

# Service providers
**We do not get paid by any service providers!** We are not affiliated with them in any way. We chose them purely for professional reasons. But we do not exclude partnership in the future.

### Hosting
SelfPrivacy supports two hosting providers: [Hetzer](https://www.hetzner.com/) and [DigitalOcean](https://digitalocean.com)

Both were chosen because of low price and acceptable level of service, quality REST API.

Candidates:
- Own personal iron server. **Our main priority right now**;
- A service provider that will provide an API to deploy an iron server. Outside [FVEY](https://en.wikipedia.org/wiki/Five_Eyes);
- OVH
- Scaleway

There's also free [Oracle Cloud](https://docs.oracle.com/en-us/iaas/Content/FreeTier/freetier_topic-Always_Free_Resources.htm), but where you don't pay, you're usually a commodity.

### DNS
There's a choice between [Cloudflare](https://cloudflare.com), [deSEC](https://desec.io/), or [DigitalOcean DNS](https://www.digitalocean.com/).

[deSEC](https://desec.io/) is a more private option and is recommended by default.

[Cloudflare](https://cloudflare.com) likely collects data in proxy traffic mode, otherwise it's hard to explain why they would offer such services for free. **In our case, we don't proxy anything and use it only as a DNS server.**

### Backup repository
We use [Backblaze](https://www.backblaze.com/).

The first 20GB are free and significantly cheaper than AWS. [Backblaze](https://www.backblaze.com/) publishes its hardware developments in open source. They also [shares](https://www.backblaze.com/b2/hard-drive-test-data.html) very useful statistics on disk failures, based on which one can choose the most reliable and tested option.

In the future, we might replace them with a self-hosted solution or a peer-to-peer one. **Currently, this is not a top priority since the data is encrypted, and the service provider only sees the IP address of your server, not the device with the application.**