crystalhansen

Discussions on code language development and projects associated with it.

Building Sovereign Social Automation with Meta's System Users

A technical guide on bypassing session flakes using Meta System Users for multi-tenant SaaS.

3 min read · 2026

React Login Series - Building a Login Feature | 7 Part Series

A production-style authentication system built with React, Tailwind, using localStorage, API abstraction, and full testing coverage.

6 min read · 2025

Building a Studio Booking App

Ever want to build a booking app and see what is under the hood of such a system?

4 min read · 2025

Multi-Tenant FROM Address Resolution & Spring EmailService

How to build a Spring @Service that resolves the correct sender address per tenant and renders per-tenant email templates from a database or file fallback.

11 min read · April 12, 2026

2026 · aws ses spring-boot java multi-tenant email · engineering backend
Docker Cheatsheet for the Mindless

Docker cheat sheet for quick reference of common tasks.

4 min read · March 19, 2026

2026 · docker restart compose · docker
Designing a Multi-Tenant SaaS Where Each Industry Feels Like Its Own Product

Building Platforms that work.

5 min read · March 15, 2026

2026 · multi-tenant platforms architecture branding spring-boot aws java · SaaS-Platforms
The GPU-less AI Server: Running Heavy Python Models and Java Apps on a Budget

Running a GPU-less Spring Boot app with python models.

3 min read · February 10, 2026

2026 · pyton integration gpu-less ai-server · AI GPU-less
Building a Dropin Chatbot Widget for any SPA App

3 min read · February 03, 2026

2026 · react chatbot UI integrations API · react-posts