Find Interview Questions for Mobikwik

Right Answer:
Webhooks are user-defined HTTP callbacks that are triggered by specific events in a web application, allowing real-time data transfer. They differ from APIs in that APIs require a request to be made to receive data, while webhooks automatically send data when an event occurs without needing a request.

Right Answer:
API authentication is the process of verifying the identity of a user or application trying to access an API. Common methods include:

1. **API Keys**: Unique keys provided to users to access the API.
2. **Basic Authentication**: Uses a username and password encoded in Base64.
3. **OAuth**: A token-based authentication method that allows users to grant limited access to their resources without sharing credentials.
4. **JWT (JSON Web Tokens)**: A compact, URL-safe means of representing claims to be transferred between two parties, often used for stateless authentication.
5. **HMAC (Hash-based Message Authentication Code)**: Uses a secret key to create a hash of the request, ensuring data integrity and authenticity.

Right Answer:
The common status codes in HTTP responses are:

- **200**: OK
- **201**: Created
- **204**: No Content
- **400**: Bad Request
- **401**: Unauthorized
- **403**: Forbidden
- **404**: Not Found
- **500**: Internal Server Error
- **502**: Bad Gateway
- **503**: Service Unavailable

Right Answer:
The different types of APIs are:

1. **Open APIs (Public APIs)** - Available to developers and third parties.
2. **Internal APIs (Private APIs)** - Used within an organization.
3. **Partner APIs** - Shared with specific business partners.
4. **Composite APIs** - Combine multiple endpoints into a single call.
5. **Web APIs** - Accessible over the internet using HTTP/HTTPS.

Right Answer:
RESTful principles include:

1. **Statelessness**: Each API call must contain all the information needed to understand and process the request, with no stored context on the server.
2. **Client-Server Architecture**: The client and server are separate, allowing for independent development and scalability.
3. **Uniform Interface**: A consistent way to interact with resources, typically using standard HTTP methods (GET, POST, PUT, DELETE).
4. **Resource-Based**: APIs should expose resources (data entities) through URIs, and clients interact with these resources.
5. **Representation**: Resources can be represented in various formats (like JSON or XML), and clients can request the format they prefer.
6. **Cacheability**: Responses should indicate whether they can be cached to improve performance and reduce server load.

These principles guide the design of APIs to be scalable, efficient, and easy to use.

Right Answer:
* **Clear Sprint Goals:** Define specific, measurable, achievable, relevant, and time-bound (SMART) goals for each iteration.
* **Daily Stand-ups:** Facilitate short, focused daily meetings to identify roadblocks and coordinate efforts.
* **Sprint Backlog Management:** Keep the sprint backlog refined, prioritized, and realistic based on team capacity.
* **Timeboxing:** Adhere to time limits for meetings and tasks to prevent scope creep and maintain momentum.
* **Focus on Value:** Prioritize tasks that deliver the most business value within the iteration.
* **Remove Impediments:** Proactively identify and resolve obstacles that hinder the team's progress.
* **Limit Work in Progress (WIP):** Encourage the team to focus on completing tasks before starting new ones.
* **Continuous Feedback:** Regularly review progress, gather feedback, and adapt plans as needed.
* **Defined "Definition of Done":** Ensure a clear understanding of what it means for a task to be considered complete.
* **Team Collaboration & Communication:** Foster open and effective communication and collaboration within the team.

Right Answer:
Agile is an iterative and incremental approach to project management that focuses on collaboration, flexibility, and customer satisfaction. Unlike traditional, sequential (waterfall) methods, Agile embraces change throughout the project lifecycle through short development cycles called sprints.

Right Answer:
I would assess the organization's context, choose a suitable scaling framework like SAFe or LeSS based on needs, implement it incrementally with training and coaching, focusing on value delivery, and continuously inspect and adapt the implementation based on feedback and results.

Right Answer:
We prioritize features or tasks in an Agile sprint using a combination of factors like business value, risk, effort/size, dependencies, and urgency. Product Owner usually leads this, using techniques like MoSCoW (Must have, Should have, Could have, Won't have) or story pointing, to ensure the most valuable items are tackled first.

Right Answer:
Agile ceremonies are recurring meetings within a sprint to facilitate communication, planning, and continuous improvement.

* **Sprint Planning:** The team decides what work to complete in the upcoming sprint. They discuss user stories, estimate effort, and define the sprint goal.

* **Daily Stand-up:** A brief daily meeting where the team shares progress, identifies roadblocks, and coordinates efforts. Each member typically answers: What did I do yesterday? What will I do today? Are there any impediments?

* **Sprint Review:** The team demonstrates the completed work to stakeholders, gathering feedback and ensuring alignment with expectations.

* **Sprint Retrospective:** The team reflects on the past sprint, identifying what went well, what could be improved, and defining action items to enhance future performance.

Right Answer:
Clustering in data analysis is the process of grouping similar data points together based on their characteristics, without prior labels. It is an unsupervised learning technique. In contrast, classification involves assigning predefined labels to data points based on their features, using a supervised learning approach.

Right Answer:
Exploratory Data Analysis (EDA) is the process of analyzing and summarizing datasets to understand their main characteristics, often using visual methods. It helps identify patterns, trends, and anomalies in the data before applying formal modeling techniques.

Right Answer:
The purpose of feature engineering in data analysis is to create, modify, or select variables (features) that improve the performance of machine learning models by making the data more relevant and informative for the analysis.

Right Answer:
Supervised learning uses labeled data to train models, meaning the output is known, while unsupervised learning uses unlabeled data, where the model tries to find patterns or groupings without predefined outcomes.

Right Answer:
Data normalization is the process of organizing data in a database to reduce redundancy and improve data integrity. It involves structuring the data into tables and defining relationships between them. Normalization is important because it helps eliminate duplicate data, ensures data consistency, and makes it easier to maintain and update the database.

Right Answer:
To prove that all nodes in a symmetric and transitive graph can communicate with each other, we can use a depth-first search (DFS) or breadth-first search (BFS) algorithm. Here’s a simple implementation in Python:

```python
def can_communicate(graph):
n = len(graph)
visited = [False] * n

def dfs(node):
visited[node] = True
for neighbor in graph[node]:
if not visited[neighbor]:
dfs(neighbor)

# Start DFS from the first node
dfs(0)

# Check if all nodes were visited
return all(visited)

# Example usage:
# graph = [[1, 2], [0, 2], [0, 1]] # Example of a symmetric and transitive graph
# print(can_communicate(graph)) # Output: True
```

This code defines a function `can_communicate` that checks if all nodes in