# Fundamentals - 217 pages (Basic Package)

## Measuring performance
- ab
- jmeter
- Inspector
- Telescope
- OpenTelemetry
- XDebug + qcachegrind
- Clockwork
- htop
- How to start measuring performance?

## N+1 queries
- Solutions
- Prevent lazy loading
- Let the client decide what it wants

## Multiple resources
## Pagination
- Cursor pagination

## Database indexing
- Theory Arrays
- Linked list
- Binary tree
- Binary search tree (BST) Indexing in the early days
- Single-level indexing
- Multi-level indexing B-Tree
- Problems with B-Trees B+ Trees
- Index access types const
- range
- range (again) index
- ALL
- Select *
- Composite indexes Cardinality
- Database indexing in practice Listing posts by status Feed
- Publishing posts
- Avoiding memory problems Avoiding spamming the database Measuring performance

## Async workflows
- Web scraping with jobs Concurrent programming
- Concurrent programming
- fork
- Concurrent HTTP requests Queues and workers
- Queues and workers
- supervisor
- Multiple queues and priorities 
- Optimizing worker processes

## Chunking large datasets
- Exports
- Imports
- Generators & LazyCollections
- PHP generators
- Imports with generators 
- Imports with LazyCollections 
- Reading files
- Deleting records

## Miscellaneous
- fpm processes 
- nginx cache
- Caching static content
- Caching fastcgi responses 
- MySQL slow query log
- Monitoring database connections
- Docker resource limits
- Health check monitors

# System design and architecture - 145 pages (Premium Package)
Building an analytics platform

## Architecture
- v1
- v2 
- v3 
- v4 
- v5
## PageView service 
## Analytics service
- Page views 
- Unique visitors 
- Most visited pages
## Measuring performance 
## Indexing
- site_id index
- visited_at and site_id composite index 
- site_id and visited_at composite index
## Denormalization 
## Hashing URLs 
## Redis
### Sets 
### Sorted sets 
### Page views
- Querying page views
- Daily and monthly page views 
- Scaling down the problem 
- Inserting page views
- Time complexity
### Unique visitors
- Querying unique visitors
- Daily and monthly unique visitors 
- HyperLogLog
- Daily unique visitors
- Monthly unique visitors
- Hourly unique visitors
- Scaling down the problem 
- Inserting unique visitors
- Time complexity
- Memoization
### Most visited pages
- Querying most visited pages 
- Scaling down the problem 
- Inserting most visited page views 
- Time complexity
### Cleaning up data
### Falling back to MySQL 
### Avoiding accidental data loss 
### Caching
### Conclusion
## Architecture v6: CQRS 
- The event stream