SaaS Architecture Guide

Generate system diagrams, compare databases, spot security gaps with AI assistance.

Tasks.org syncs Android tasks to CalDAV cleanly. There is no web UI for that data. The fix is a stateless PWA on top of the CalDAV server you already run.

Get a complete architecture blueprint and phased build roadmap.

Sanitized production infrastructure case study demonstrating end-to-end operational ownership. Reusable infrastructure as code and Deno automation coordinate Docker Compose delivery behind Traefik, VictoriaMetrics and Gatus monitoring, Restic integrity checks, retention and restore tooling, and Authelia SSO with 2FA.

Open-source, self-hostable finance tracking for individuals, families, and small businesses. Features double-entry accounting, multi-currency support, real-time collaboration, and PWA capabilities.

DIY ESP32-based air quality monitoring system measuring PM1.0, PM2.5, PM10 particles, CO2, temperature, and humidity. Integrates with Home Assistant for smart home automation and real-time alerts.

My Android tasks live in Tasks.org. Tasks.org syncs them to CalDAV. Every desktop client I tried either pulled its own backend or fought Tasks.org for ownership of the data — I needed a thin UI on top of the same VTODO files. Built it on Deno + Hono + Preact Signals: a CQRS layer over a CalDAV adapter (one PROPFIND/PROPPATCH/PUT/DELETE interface that speaks both Radicale and Stalwart), AES-GCM at rest for server credentials, SQLite holding only user accounts and encryption keys — never for todos. Result: 5 calendars and 140+ todos on a single Hetzner box, deployed since June 2026, including a Radicale-to-Stalwart migration that moved zero VTODO data.

Native Deno Model Context Protocol server for CalDAV. Events + tasks, zero npm dependencies, single binary. Works with OpenCode, Claude Desktop, Cursor, and Open WebUI.

Internal health probe bridge for services behind SSO proxies. Originally Deno+TS, rewritten to Go as a single 10 MB distroless binary. Probes HTTP endpoints through Authelia-secured gateways — built for Gatus and other monitoring tools that lack SSO support.

Full SaaS MVP from idea to live deployment in 21 days.

Run your own CI/CD on a $10 VPS. Docker Compose setup, GitHub integration.

Repeatable deployment, observability, recovery, security, and cost control after launch.

Decision rubric for compliance, elasticity, geography, team capacity, uptime, recovery, and cost.

Sanitized case study of reusable IaC, Deno deployment automation, monitoring, recovery tooling, and identity controls.

Architecture for MCP servers, working CalDAV example, lessons from 4 production servers.

Production-grade LLM pipelines, RAG systems, and autonomous subagents.

Connect your AI to your CRM, database, email, and internal APIs.

What I learned shipping the same SaaS skeleton over and over for paying clients. Group core, personal groups, REST + CQRS, offline sync, an outbox processor — and a deliberate decision to ship it as a template, not a framework.

A founder-readable framework for choosing managed cloud, dedicated, or hybrid SaaS infrastructure based on workload, team, compliance, recovery, and total cost.

Or why so many developers abandon their attempts to release a product