Backend Developer Lead Interview Questions and Answers

I would investigate the root cause of the lagging service and optimize the code or infrastructure accordingly.

• Identify the bottleneck in the service by analyzing logs and performance metrics

• Optimize the code by refactoring or improving algorithms

• Scale the infrastructure by adding more resources or implementing load balancing

• Implement caching mechanisms to reduce response time

• Monitor the service continuously to ensure optimal performance

Django Tenant is a Django app that enables multi-tenancy in a single Django project.

• Django Tenant allows you to create multiple instances of a Django application within a single database.

• Each instance, or tenant, has its own isolated data and can be accessed using a unique subdomain or URL.

• It provides a simple and efficient way to build and manage multi-tenant applications.

• Django Tenant is commonly used in SaaS (Software as a Service) applications.

• It helps in reducing infrast...read more

Managed infrastructure for multiple projects, including cloud services and server maintenance

• Implemented and maintained cloud services such as AWS or Azure

• Managed server configurations and updates

• Implemented monitoring and alerting systems for infrastructure

• Automated deployment processes using tools like Ansible or Terraform

Kafka is run in cluster mode by setting up multiple Kafka brokers to distribute data and provide fault tolerance.

• Set up multiple Kafka brokers on different machines.

• Configure each broker with unique broker.id and port number.

• Update the server.properties file on each broker to specify the Zookeeper connection string.

• Start each broker individually to join the cluster.

• Use replication factor and partitioning to ensure fault tolerance and scalability.

Object-oriented programming concepts that help in creating modular and reusable code.

• Abstraction - hiding implementation details

• Encapsulation - binding data and functions together

• Inheritance - creating new classes from existing ones

• Polymorphism - using a single interface to represent multiple types

• Composition - combining objects to create more complex ones

Variable scope refers to the visibility and accessibility of variables within different parts of a program.

• Variables declared inside a function have local scope and are only accessible within that function.

• Global variables can be accessed from anywhere in the program.

• Nested functions can access variables from their parent functions.

process.nextTick is used to defer the execution of a callback function until the next iteration of the event loop, while SetImmediate is used to execute a callback function immediately after the current event loop.

• process.nextTick is more efficient for executing code asynchronously in the same phase of the event loop.

• SetImmediate is better suited for executing code asynchronously in the next iteration of the event loop.

• process.nextTick has higher priority than SetImmediate in...read more

Event loop in Node.js manages asynchronous operations by executing callback functions when certain events occur.

• Event loop is responsible for handling I/O operations and executing callbacks.

• It allows Node.js to perform non-blocking operations efficiently.

• Event loop continuously checks the event queue for new events to process.

• Example: setTimeout function in Node.js uses event loop to schedule the callback function to be executed after a certain delay.