I'll talk about lessons learnt, key decisions & tradeoffs made while building cloudskew.com (an online editor for creating cloud architecture diagrams). The architecture of cloudskew is publicly documented: https://assets.cloudskew.com/assets/misc/cloudskew-architecture-20200116.png

Some topics I'll touch upon:
- Why PaaS + Serverless instead of IaaS?
- Horizontal auto-scaling.
- Queue based load-levelling.
- Centralized configuration management
- Debouncing calls to server
- Continuous Integration vs deployment vs release
- Upcoming architectural changes to handle scale