Travelex Junior Software Engineer Interview Questions and Answers

Developed a web application for online shopping with user authentication and payment gateway integration.

• Used React.js for front-end development

• Implemented user authentication using JWT tokens

• Integrated Stripe API for payment processing

Optimization techniques are methods used to improve the efficiency and performance of software applications.

• Use of algorithms like dynamic programming and greedy algorithms

• Profiling and performance tuning to identify bottlenecks

• Code refactoring to improve readability and maintainability

• Utilizing caching and memoization for faster access to data

• Parallel processing and multi-threading for improved concurrency

Find duplicates in an ArrayList of strings.

• Iterate through the ArrayList and use a HashSet to keep track of seen elements.

• If an element is already in the HashSet, it is a duplicate.

• Store the duplicates in a separate ArrayList or print them directly.

Primary is used to define a primary bean when multiple beans of the same type are present, while Qualifier is used to specify which bean to autowire when multiple beans of the same type are present.

• Primary annotation is used to give a higher preference to a bean when multiple beans of the same type are present in the Spring application context.

• Qualifier annotation is used to specify which bean to autowire when multiple...read more

Fault tolerance in Microservices can be achieved through redundancy, graceful degradation, and circuit breakers.

• Implementing redundancy by having multiple instances of each microservice running to handle failures.

• Using graceful degradation to ensure that the system can still function even if certain microservices are unavailable.

• Utilizing circuit breakers to prevent cascading failures by temporarily stopping requests t

Implementing Spring Security involves configuring security settings in the Spring application.

• Add Spring Security dependency in pom.xml

• Configure security settings in SecurityConfig class

• Define user roles and permissions

• Use annotations like @EnableWebSecurity and @Secured

OAuth 2 is an authorization framework that allows a third-party application to obtain limited access to an HTTP service.

• OAuth 2 is used for delegated access, allowing a user to grant a third-party application access to their resources without sharing their credentials.

• It involves the use of access tokens, which are issued by the authorization server after the user authenticates and authorizes the application.

• OAuth 2 su...read more

Java uses automatic memory management through garbage collection to allocate and deallocate memory.

• Java uses garbage collection to automatically manage memory by deallocating objects that are no longer needed.

• The JVM has a heap where objects are allocated and garbage collection is performed to reclaim memory.

• Java provides the 'finalize()' method for objects to perform cleanup before they are garbage collected.

• Memory le...read more

Different types of garbage collection algorithms in software development.

• Mark and Sweep: Identifies and removes unreachable objects.

• Generational: Divides objects into different generations based on age.

• Parallel: Uses multiple threads to perform garbage collection concurrently.

• Incremental: Spreads garbage collection work over multiple cycles to reduce pause times.

Executors are a class that provides factory and utility methods for Executor, ExecutorService is an interface that represents an asynchronous execution service.

• Executors class provides factory and utility methods for Executor interface

• ExecutorService is an interface that represents an asynchronous execution service

• ExecutorService extends Executor interface

• ExecutorService provides methods to manage termination and produ...read more