1. Use CDN networks
2. Load balancers
3. Cache static content and increasing the caching capacity with cache clusters.
4. Have microservice architecture.
5. Use appropriate programming languages, based on the feature to be built.
6. Use containers in swarm mode for deployment.
7. Auto scale infrastructure.
8. Queuing mechanism.
9. Test driven development.
10. Having CI and CD. It helps in faster delivery, bug fixes and less maintenance.

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Database

1. Use NoSQL, or combination of NoSQL and SQL for best performance.
2. Shard database for scalability.
3. Cache Shared indexes.
4. Removing unused data from DB or filesystems.
5. Indexing
6. Query optimizations
7. Using replica sets to read data.
8. Using views to read data.
9. If using Mongoose with MongoDB, use .lean() function for getting the direct JavaScript object avoiding any ORM processing.