Backend: Python / SqlAlchemy
DB: Postgres
Cache: Redis
Frontend: React / Redux / Emotion / Socket.io
Reverse Proxy: Traefik
Marketing Site: Next.js
CDN/File hosting: Cloudflare, R2
Backups: Tarsnap
Deployment: Docker / Docker Compose
Server configuration: Ansible
Mobile: React Native
Payments: Stripe
Email (Transactional/Marketing): Postmark
If I were to start today, I would probably start with something else. But this stack has served me well for years, and still going strong with 36 apps and counting. I'm constantly evolving it as the tech progresses.