GIT

• How do you work with git in regular basis?
• How to resolve conflicts?
• Commit was removed. Is it possible to revert this action?
• What is a git cache?
• What flows did you use to introduce new feature to production?
• What is a difference between Merge and Rebase?

Git repositories

• Bitbucket
• Github
• Gerrit

CICD

• Jenkins/Bamboo
• Integration Tests
• Straight to production
• Staging environments

Agile

• Tell us about your experience with scrum?
• Ceremonies in scrum and main roles
• What is Kanaban?

Good Practices

• Code Reviews
• What for do we need code review?

Testing

• Different kinds of tests?
• How should tests proportion looks like?
• What is TDD?
• Are unit tests required?
• What structure do you use for single test. (Given When Then, Arrange Act Assert)
• How you name specific test case ? (should...)

Design

• OOP
• DDD
• BDD

OOP

• Acronyms SOLID, DRY
• Encapsulation, Abstraction, Polimorphism, Inheritance
• Design patterns - categories, differences, patterns composition

Java

• Java Object Class methods
• Hash and equals methods contracts
• How to compare two object in Java? What should we implement or/and extend to accomplish it?
• Generics - what is it?
• Java annotations
• How to intruduce Amphibious to codebase using base classes Car and Boat?
• final keyword
• List<? super B> VS List<? extends B> where B extends A, C extends B and D extends B

Java Memory Model

• Stack - how can we get stackoverflow exception
• Heap - how can we get OutOfMemory Exception
• GC
  • differences,
  • How do different gc works?
  • What for do we need GC?
  • G1 - why is it awesome?

Testing libs

• JUnit,
• Mockito,
• AssertJ,
• Wiremock
• Spock

Java Collections

• List

• Set

• Map

  • Hash Map - O notation

• Thread safe collections in Java

Java Concurrency

• Semaphore
• Monitor
• Threads pool
• synchronized keyword - what object will be used: when mathod is static and for regular method.
• What is cirtical section?
• What does that mean that operation is atomic?
• Volatile keyword
• Implement Singleton

Java 8

• What features were introduced in java 8?
• What for do we need Optional?
• What is a keyword default in Java interface?

Java 9

• New feaures?
• HTTP Client
• RxJava
• Modularization / OSGi

Java Streams

• filter, map, flatMap, reduce, group by, collect
• How many times can you invoke operations on single stream?
• Two kinds of opperations on streams.

HTTP

HTTP

• HTTP methods
• HTTP status codes

REST API

• What is it?
• How resources are stored? (Nouns Verbs)
• What HTTP methods should be used?
• What operations are idempotent?

Spring

• What design pattern is most used pattern in spring framework?
• Dependency Injection
• AOP in spring
• Spring annotation?
• How do you impelement REST api in Spring?
• Transactional annotation?
• Components
  • Controller
  • Service
  • Repository
  • Configuration
• Configuration
  • XML
  • Java classes

Spring Boot

• What is a difference between spring boot and spring?
• What for do we need Spring Boot?
• Is it possible to use xml configuration files?
• What is the dafault http server for Spring Boot?
• Available http servers from the box?
• WAR vs JAR

Spring Cloud

• Modules of spring
• What is circut breaker?
• Circut breaker impelementation using semaphore and thread pools: What is the difference?

Building Dependency Tools

• Ant,
• Maven,
• Gradle
• Maven scopes

Databases

Hibernate

• n + 1 problem
• What is transaction?
• Optimistic Locking vs. Pessimistic Locking

SQL

• What databases did you use?
• Left Righ Inner Outer Full Join

NoSQL

• SQL vs NoSQL
• Mongo
  • Optimistic Lock - how can be implemented?
  • How values are stored in mongo?

Redis

• How the values are stored in redis?
• For what we can use redis?
• Redis vs memcache

Microservices

• Communication channels between microservices

Queues

• Kafka

  • How kafka works?
  • Topics Partitions
  • Multiple readers broadcasting
  • Kafka cluster

• RabitMq

Case study

• How will you implement newsletter functionality?