Java

What are the main features introduced in the Servlet 3 specification?

Which interface extends the other: Queue extends Deque or Deque extends Queue?

What are the differences between using HashMap with synchronized methods and using ConcurrentHashMap in a multithreaded environment?

Junior — Middle

Effective MobileАльфа-Банк

What is a namespace in XML?

How does HashMap behave when adding an element with a null value, if the hashCode method always returns the same number?

What methods can be used to pass a lambda expression through the Optional class?

What difficulties can arise when using the Read Committed isolation level in transactions?

Junior — Middle

OZON

Can you explain how the OAuth 2.0 protocol works and its main components?

Have you used a centralized log collection system in your projects?

Junior — Middle

СБЕР Корпус

What is the difference between the Builder design pattern and the Facade design pattern?

What do you know about creating custom JSP tags?

What are the main difficulties and disadvantages associated with inheritance in Java?

What methods of integrating a database with a Java application exist?

What implementations of the Inversion of Control (IoC) principle do you know?

Explain what the abbreviation MDC means in the context of databases or data storage systems.

Junior — Middle

Альфа-Банк

What is JWT (JSON Web Token) used for?

Why does the Map collection occupy a unique place in the hierarchy of collections?

How is data integrity ensured when using transactions in Spring together with Hibernate?

Have you conducted performance evaluations of queries in your system?

Junior — Middle

СБЕР

In which cases is it recommended to use the volatile keyword in Java?

Junior — Middle

IT One