Deloitte Senior Software Developer (Java) interview questions

how Hashmap internally works and how to fix race condition and what is rehashing

L-1: Top10Employees list using Java 8 streams. Salary > 50000/- using Java 8 streams Salary > 50000/- and age < 40 (DOB) using Java 8 streams {1,2,3,4,5} sum = 6 Output {1,5} {2,4} using loops Questions: Java8 streams Functional interfaces HashMap internally working Red black tree @SpringBoot Application What happens without giving to the query params in @put method Schedulers CB pattern Uses of Kafka L-2: Spring boot & Microservices architect How to communicate Micro services How to call external APIs