What is the main difference between using the map and flatMap methods in the Stream API when processing data streams?
Junior — Middle
167
Java
14627
265
Unfortunately, do you have practical experience in creating and maintaining microservices architectures?
Junior — Middle
167
Tell me about SQL query optimization by 40-50%.
Senior
167
//Given an array of numbers where all numbers except one have a pair, //find the number that appears only once // <= [1, 0, 3, -2, 9, 9, 1, -2, 0] // => 3 int find(int[] arr){ //TODO }
Senior
167
Where can request scope be useful?
Senior
167
What are the idempotency rules for HTTP methods? How to solve the problem of duplicate POST requests?
Senior
167
How to implement the open-closed principle in object-oriented programming?
Junior — Middle
166
Can a singleton service (single instance) be high-load?
Senior
166
Why is the finalize() method needed?
Senior
166
Tell me about the memory structure in JVM — what are the segments, how does it work?
Senior
166
The database is large, indexes are built, the plan has been reviewed — what else can be done for optimization?
Senior
166
Tell about streams in Java: what groups do methods fall into and what is the difference?
Middle
166
What events does ApplicationContext in Spring know?
Senior
166
How can changes made be saved before switching to another branch in version control systems?
Junior — Middle
166
Algorithmic problem: given an integer array, move all zeros to the end, preserving the order of other elements (e.g., [1,0,3,0,1] → [1,3,1,0,0])
Senior
166
How many civilian airliners were over the Moscow region yesterday? (Fermi estimation question)
Senior
166
How to solve the consistency problem when using Kafka transactions between two services?
Senior
166
What HTTP methods were used in designing REST API? What is the difference between PATCH and POST?
Senior
166
Tell about the Outbox pattern for guaranteed message delivery.
Senior
165
How have you implemented log collection and monitoring in a microservices architecture?
Senior
165