Knowing only hardware assembly

Practical Python or JavaScript skills

Avoiding programming languages to prevent bias

Understanding the DOM and how pages are rendered

Understanding HTML/XML structure

Normalizing or scaling numerical features

Detecting and deciding how to treat outliers

Creating web beacons to increase tracking coverage

Cleaning inconsistent or duplicate records

Handling missing values

Private cryptographic keys of the user

Exit page or final page in a session

Referrer URL or traffic source

Compiler diagnostics for frontend code

Visited URLs or page identifiers

Page visit order

Social media likes

Database metadata

Visited pages

Time on page

Network routing

NLP-based classification

Packet sniffing

Text analysis

Image and video analysis

Stop-word removal

Lemmatization

Stemming

Tokenization

CSS selection

Statistical analysis

Filesystem defragmentation

Machine learning

Natural language processing

Information retrieval

Group user activity

Calculate bounce rates

Encrypt passwords

Detect meaningful sessions

Build knowledge graphs