Tech lead java

Description

Auto-generated position for Tech lead java

Interview Questions (161)

Q1Can you describe a challenging technical problem you encountered in a Java project and how you resolved it?
Experience
Q2How do you ensure code quality and maintain coding standards within your team during the development process?
Behavioral
Q3Can you describe a complex Java architecture you designed and the key decisions that influenced your design choices?
Experience
Q4How do you approach mentoring junior developers to ensure they follow best coding practices?
Behavioral
Q5Can you describe a challenging Java project you led and the architectural decisions you made to overcome those challenges?
Experience
Q6How would you handle a situation where a junior developer consistently submits code that does not meet the team's quality standards?
Behavioral
Q7Is Java platform independent?
Technical
Q8What are the top Java features?
Technical
Q9What is JVM?
Technical
Q10What is JIT?
Technical
Q11What are memory storages available with JVM?
Technical
Q12What is a classloader?
Technical
Q13What is the difference between JVM, JRE, and JDK?
Technical
Q14What are the differences between Java and C++?
Technical
Q15Explain public static void main(String args[]) in Java.
Technical
Q16What is Java String Pool?
Technical
Q17What will happen if we don't declare the main as static?
Technical
Q18What are packages in Java?
Technical
Q19Why are packages used?
Technical
Q20What are the advantages of packages in Java?
Technical
Q21Explain different data types in Java.
Technical
Q22When is a byte datatype used?
Technical
Q23Can we declare a pointer in Java?
Technical
Q24What is the default value of byte datatype in Java?
Technical
Q25What is the default value of float and double datatype in Java?
Technical
Q26What is the wrapper class in Java?
Technical
Q27Why do we need wrapper classes?
Technical
Q28Differentiate between instance and local variables.
Technical
Q29What are the default values assigned to variables and instances in Java?
Technical
Q30What is a class variable?
Technical
Q31What is the default value stored in local variables?
Technical
Q32Explain the difference between instance variable and a class variable.
Technical
Q33What is a static variable?
Technical
Q34What is the difference between System.out, System.err, and System.in?
Technical
Q35What do you understand by an IO stream?
Technical
Q36What is the difference between the Reader/Writer and InputStream/OutputStream class hierarchies?
Technical
Q37What are the super most classes for all the streams?
Technical
Q38What are the FileInputStream and FileOutputStream?
Technical
Q39What is the purpose of using BufferedInputStream and BufferedOutputStream classes?
Technical
Q40What are FilterStreams?
Technical
Q41What is an I/O filter?
Technical
Q42How many ways can you take input from the console?
Technical
Q43What is the difference in the use of print, println, and printf?
Technical
Q44What are operators?
Technical
Q45How many types of operators are available in Java?
Technical
Q46Explain the difference between >> and >>> operators.
Technical
Q47Which Java operator is right associative?
Technical
Q48What is the dot operator?
Technical
Q49What is covariant return type?
Technical
Q50What is the transient keyword?
Technical
Q51What is String in Java?
Technical
Q52What are the differences between String and StringBuffer?
Technical
Q53What are the differences between StringBuffer and StringBuilder?
Technical
Q54Which among StringBuilder or StringBuffer should be preferred when there are a lot of updates required to be done in the data?
Technical
Q55Why is StringBuffer called mutable?
Technical
Q56How is the creation of a String using new() different from that of a literal?
Technical
Q57What is an array in Java?
Technical
Q58On which memory are arrays created in Java?
Technical
Q59What are the types of an array?
Technical
Q60Why does the Java array index start with 0?
Technical
Q61What is the difference between int array[] and int[] array?
Technical
Q62How to copy an array in Java?
Technical
Q63What do you understand by the jagged array?
Technical
Q64Is it possible to make an array volatile?
Technical
Q65What are the advantages and disadvantages of an array?
Technical
Q66What is an object-oriented paradigm?
Technical
Q67What are the main concepts of OOPs in Java?
Technical
Q68What is a deadlock? How can you prevent it?
Technical
Q69What’s the purpose of `volatile`?
Technical
Q70How does `ThreadLocal` work?
Technical
Q71When should you use `Callable` over `Runnable`?
Technical
Q72How is `HashMap` implemented internally?
Technical
Q73What is the difference between `ArrayList` and `LinkedList`?
Technical
Q74When to use `ConcurrentHashMap` vs `Collections.synchronizedMap()`?
Technical
Q75What is fail-fast vs fail-safe iterator?
Technical
Q76How do `TreeMap` and `HashMap` differ?
Technical
Q77What are the four pillars of OOP in Java?
Technical
Q78What is the difference between composition and inheritance?
Technical
Q79What is the Liskov Substitution Principle?
Technical
Q80Can an interface have static methods?
Technical
Q81What is garbage collection in Java?
Technical
Q82Explain the Java memory model.
Technical
Q83What is PermGen vs Metaspace?
Technical
Q84How does G1GC differ from CMS?
Technical
Q85How can you detect and fix memory leaks?
Technical
Q86What is a functional interface?
Technical
Q87Difference between `map()` and `flatMap()` in Streams?
Technical
Q88What are method references?
Technical
Q89What is Optional and how should it be used?
Technical
Q90What is the purpose of default methods in interfaces?
Technical
Q91How does Spring Boot auto-configuration work?
Technical
Q92Difference between `@Component`, `@Service`, `@Repository`?
Technical
Q93How does Spring manage bean lifecycle?
Technical
Q94What is the role of `@ConditionalOnProperty`?
Technical
Q95How do you implement inter-service communication?
Technical
Q96What is the difference between synchronous and asynchronous calls?
Technical
Q97How do you implement retry, fallback, and circuit breaker?
Technical
Q98How do you ensure backward compatibility between services?
Technical
Q99What’s the role of API Gateway in microservice architecture?
Technical
Q100How do you secure REST endpoints?
Technical
Q101What is the difference between OAuth and JWT?
Technical
Q102How do you implement RBAC in Spring Security?
Technical
Q103How do you protect microservices against DDOS or abuse?
Technical
Q104What is rate limiting and how do you implement it?
Technical
Q105What is Spring Cloud Config Server?
Technical
Q106How do you implement distributed tracing?
Technical
Q107How does actuator help in production?
Technical
Q108How to monitor microservices in real time?
Technical
Q109How do you achieve zero-downtime deployment?
Technical
Q110What is blue-green deployment?
Technical
Q111What happens if a service crashes? How do you recover?
Technical
Q112How do you handle data consistency in distributed transactions?
Technical
Q113What is a Saga pattern and when should you use it?
Technical
Q114What is the Singleton pattern? How do you implement it in Java?
Technical
Q115How is Factory pattern different from Abstract Factory?
Technical
Q116What is the Strategy pattern?
Technical
Q117Where is the Builder pattern commonly used?
Technical
Q118What is the Observer pattern?
Technical
Q119Explain the Proxy pattern with real-world usage.
Technical
Q120Difference between Adapter and Decorator pattern?
Technical
Q121What is the Template Method pattern?
Technical
Q122When do you use Command pattern?
Technical
Q123What’s the benefit of Chain of Responsibility?
Technical
Q124What is Dependency Injection? How does Spring use it?
Technical
Q125How is MVC implemented in Spring?
Technical
Q126What is AOP? Common use cases?
Technical
Q127How is Lazy Initialization useful in patterns?
Technical
Q128What’s the difference between Composition and Aggregation?
Technical
Q129Can patterns introduce complexity? How do you balance it?
Technical
Q130What’s the role of the Mediator pattern?
Technical
Q131Example of Flyweight pattern in Java APIs?
Technical
Q132How do you reverse a LinkedList without using extra space?
Technical
Q133Write a function to check if a string is a palindrome.
Technical
Q134What is the time complexity of HashMap operations?
Technical
Q135Explain binary search algorithm.
Technical
Q136How does QuickSort work?
Technical
Q137What’s the difference between BFS and DFS?
Technical
Q138When is a heap used in Java?
Technical
Q139Implement LRU cache.
Technical
Q140What’s a Trie? Use case?
Technical
Q141What is the difference between a stack and a queue?
Technical
Q142How do you detect a cycle in a graph?
Technical
Q143How do you find the intersection of two arrays?
Technical
Q144What’s the difference between Array and LinkedList?
Technical
Q145What is dynamic programming?
Technical
Q146What is memoization?
Technical
Q147Difference between INNER JOIN and LEFT JOIN?
Technical
Q148What is normalization?
Technical
Q149How to prevent SQL Injection in Java?
Technical
Q150What is indexing? How does it work?
Technical
Q151Difference between clustered and non-clustered index?
Technical
Q152What is ACID in databases?
Technical
Q153Explain isolation levels.
Technical
Q154What are transactions and how are they managed in Spring?
Technical
Q155What’s a deadlock in DB?
Technical
Q156How to profile slow queries?
Technical
Q157What’s the use of `JOIN FETCH` in JPQL?
Technical
Q158How do you ensure consistency in distributed DBs?
Technical
Q159What is the difference between optimistic and pessimistic locking?
Technical
Q160When to use NoSQL over RDBMS?
Technical
Q161What’s a primary key vs unique key?
Technical