Production notes on Python, FastAPI, React, security and AI engineering.https://uguraslim.com/https://uguraslim.com/blog/building-multi-tenant-saas-with-sqlalchemy-row-level-securit/https://uguraslim.com/blog/building-multi-tenant-saas-with-sqlalchemy-row-level-securit/Implement tenant isolation at the database layer using SQLAlchemy's session management and PostgreSQL policies to prevent data leaks in production SaaS applications.Wed, 20 May 2026 00:00:00 GMThttps://uguraslim.com/blog/production-audit-logging-postgresql/https://uguraslim.com/blog/production-audit-logging-postgresql/How to design scalable, queryable audit logs in PostgreSQL without performance degradation using partitioning, JSON columns, and smart indexing.Wed, 20 May 2026 00:00:00 GMThttps://uguraslim.com/blog/astro-islands-architecture/https://uguraslim.com/blog/astro-islands-architecture/Astro ships zero JavaScript by default and lets you opt in to interactivity exactly where you need it — through a pattern called Islands Architecture. Here's how it works, why it's fast, and when it's the right choice.Tue, 19 May 2026 00:00:00 GMThttps://uguraslim.com/blog/react-ai-chat-widget/https://uguraslim.com/blog/react-ai-chat-widget/How I built the AI chat widget in CitizenApp — a floating React component that sends natural language questions to Claude, optionally executes safe live SQL queries, and renders the results inline. Architecture decisions, pitfalls, and patterns that generalize.Tue, 19 May 2026 00:00:00 GMThttps://uguraslim.com/blog/cursor-claude-engineering-workflow/https://uguraslim.com/blog/cursor-claude-engineering-workflow/Not a productivity tips list. A concrete walkthrough of how I use Cursor and Claude API through an entire feature — from architecture decision to shipped code — on a real FastAPI + React project.Sun, 17 May 2026 00:00:00 GMThttps://uguraslim.com/blog/vercel-render-hybrid-deployment/https://uguraslim.com/blog/vercel-render-hybrid-deployment/Running your React frontend on Vercel Edge and your FastAPI backend on Render Docker isn't just cost optimisation — it's an architecture decision with real production consequences. Here's the full breakdown.Sat, 16 May 2026 00:00:00 GMThttps://uguraslim.com/blog/ai-assisted-engineering/https://uguraslim.com/blog/ai-assisted-engineering/AI tools don't write your architecture — they amplify it. Here's exactly how I use Claude, Cursor and GitHub Copilot across a real production project, and where human judgment is irreplaceable.Thu, 14 May 2026 00:00:00 GMThttps://uguraslim.com/blog/react-19-tanstack-query-patterns/https://uguraslim.com/blog/react-19-tanstack-query-patterns/React 19 ships with new primitives — Actions, useOptimistic, use() — that change how you think about async state. Here's how they interact with TanStack Query v5, and which patterns I've settled on after shipping with both.Tue, 12 May 2026 00:00:00 GMThttps://uguraslim.com/blog/fastapi-jwt-rotation/https://uguraslim.com/blog/fastapi-jwt-rotation/Most JWT implementations have a silent security flaw: refresh tokens that never expire. Here's how to implement proper rotation with reuse detection in FastAPI.Sun, 10 May 2026 00:00:00 GMThttps://uguraslim.com/blog/gdpr-saas-architecture/https://uguraslim.com/blog/gdpr-saas-architecture/GDPR compliance isn't a checkbox — it's an architectural decision. Here's what needs to be in place at the infrastructure level before you write the first business logic line.Fri, 01 May 2026 00:00:00 GMT