n8n: what it is, how it works and why we build on it

n8n is the workflow engine Firmatic builds nearly every automation on. In this article: how n8n works under the hood, why we prefer it over Zapier or Make, and what a production installation looks like.

What is n8n?

n8n is a fair-code workflow automation platform: a visual editor where you connect nodes (building blocks) into a workflow. Each node does one thing: an HTTP request, reading an e-mail, transforming data, calling an AI model. The crucial difference from many alternatives: n8n can run fully self-hosted — on a server you control, with your data, in the EU.

How it works technically

• Triggers start a workflow: a webhook (real-time), a cron schedule, an IMAP mailbox, a database change.
• Expressions — anywhere in n8n you can use JavaScript expressions via {{ }} to reach and transform data from earlier steps.
• Code nodes — where the built-in nodes stop, you simply write JavaScript or Python. No locked-down platform limits.
• Credentials are stored encrypted and attached per node — API keys never live in the workflow itself.
• Error workflows — a separate workflow catches failures and sends alerts, so a broken integration never lies silent.

Why n8n and not Zapier or Make?

• Cost model — Zapier charges per task; at thousands of operations a month the bill explodes. Self-hosted n8n has no per-execution limit: the same server runs 100 or 100,000 executions.
• Data ownership — your invoices and customer data don't leave the server. For GDPR-sensitive processes that's a requirement, not a luxury.
• No step limits — complex workflows with dozens of branches are normal in n8n; on task-based platforms they become unaffordable.
• Real code where needed — a Code node solves what a no-code straitjacket cannot.

What our production setup looks like

Our n8n runs in Docker on a VPS: PostgreSQL as database, nginx as reverse proxy with HTTPS, daily backups and monitoring on every workflow. For higher volumes n8n switches to queue mode: a Redis queue spreads executions across workers so traffic peaks don't drop runs. Webhooks are protected with CORS restrictions and authorisation; API keys get least-privilege scopes.

Typical n8n projects we build

An AI mail agent that reads invoices from the inbox into the books. A quote calculator where every request automatically becomes a lead, an e-mail and a notification. Order and stock sync between shop and accounting. Internal alerts when a KPI drifts. Curious what could be automated at your company? Start the free automation scan — which, of course, runs on n8n itself.