SaaS Architecture Guide

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Tasks.org syncs Android tasks to CalDAV cleanly. There is no web UI for that data. I built a web app for it; it is now being rewritten.

I review your codebase and tell you what to fix, what to rewrite and what to leave alone.

Real-time IoT control platform running in production at Gardens by the Bay, Singapore — about 200 lamp poles managed across the public-facing park, live since 2024 and still under my maintenance. Yumetronics handled the hardware and on-site pole integrations; I built the software side end-to-end: the operator web app, the backend services, the AWS infrastructure, and the deploy pipeline. Three months from kickoff to production, no prior code. The platform bridges MQTT-driven hardware control with an operator-friendly web dashboard. Pole state, sensor readings, and command acknowledgements flow over MQTT for low-latency control; database changes propagate to connected clients via PostgreSQL LISTEN/NOTIFY for a live multi-user dashboard without polling. Operators see a geographic map of every pole, scheduled automation (time-of-day, sensor-triggered, manual override), motion and ambient-light triggers, failure detection with automatic alerts through PWA push, Telegram, and WhatsApp — plus CSV and Excel exports, charts for incident reporting, role-based access (admin / operator / viewer), TOTP 2FA, and a mobile PWA so on-site staff can act from the field. The screenshots above cover every operator page.

Real-time multiplayer Truth or Dare game for Russian-speaking audiences, live at darechat.me. Built for founder Rustam Zaripov in 2022 with a backend-first architecture in one Nx monorepo: two NestJS APIs on Express (public REST + admin) using CQRS handlers, Swagger-documented at darechat.me/api, Socket.IO chat scaled across nodes via the Redis pub/sub adapter, Firebase auth + storage + FCM push notifications, Google Cloud Vision for user-uploaded image moderation, and Prisma on PostgreSQL. JWT-bearer auth across both APIs, custom Nx libraries for shared command/query handlers, and MinIO-compatible media storage. The marketing site (SvelteKit) and an Angular web app consume the same public REST API that mobile clients do — iOS and Android apps live in the founder's separate repos.

Digitize paper invoices, automating orders to suppliers, and tracking price fluctuations.

Fitness-focused social network with exercise tracking features and ML for recommendation system.

Multi-video recorder for kids. Pick a script, record scene-by-scene, and the app stitches the clips into a finished movie — with intro/ending credits and 50+ transitions. Full stack: SvelteKit app, ffmpeg.wasm video pipeline, Postgres, AWS S3 + SES, Slack + Mailchimp webhooks. Paired physical craft boxes (scripts, props, costumes) with a digital recorder so the founder's vision of physical play + digital creativity just worked. The screenshots above are a portfolio re-imagination I built later; the original client's branding wasn't mine to share.

A four-step multilingual web app for setting once-weekly Sogroya medication reminders on mobile and desktop calendars. I built the SvelteKit + TypeScript SPA, five-language flow (English, French, German, Portuguese, and Japanese), privacy consent, dose/day/time selection, and in-browser ICS generation. Static deployment kept the experience fast, backend-free, and easy to distribute globally.

Networking app with Tinder-like UI and Machine Learning algorithm to match like-minded people.

Manage marketing teams via a Trello-like app that utilized a marketplace for project templates.

Human text classification service freelance platform. Earn money by classifying things.

Analyze calls data from your call center and manage phone numbers based on various rules. I built the frontend of this call-analytics SaaS in AngularJS: the screens for call data and for managing phone numbers by rules.

Dashboard single-page application for search and recommendations engine as a service. I built the dashboard, a single-page AngularJS app for Sajari's search and recommendations service.

Code review report for a Node.js REST API codebase. The report covered deeply nested callbacks and inconsistent code style. After the report I interviewed seven Node.js developers in two weeks and hired the one who took the code forward.

I build your product from idea to live deployment. Backend APIs, AI integration and MCP servers are built the same way.

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.

The open-source scaffolder I deploy my own servers with: four instances in different regions, each running a different set of services.

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

Custom MCP servers that let your AI assistant read, write and act inside your own tools — CRM, database, email, calendar, internal APIs — shipped as a self-hosted Docker image you own.

Why I own my UI components instead of using shadcn, Radix or MUI: a Preact component library in ten JSR packages, rendered on the server, keyboard handling written by hand, with a live guide. What is in it, how to try it, and what is not done yet.

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.