Senior Engineer Interview

Can you describe your experience with designing and building RESTful APIs?

In my current role and previous role, I work it Restful api quite often,
We will define the database schema or action required based on the requirement and from their we build the api to address the action, we followed the conversion like the POST should be create, PUT should update, get shoud return the details
How to handle the authentication and authorization for secure purpose
Document it following SWagger UI for other teams references
We require the every endpoints should have their tests which is also a live document for developers to understand the logic, we normally use the Rspec for the test.
We also have regular catchup with the FE team to update progress and answer the questions relating to api, my role is the fullstack developer in my team so it more convinience to communicate

Your answer provides a solid overview of your experience with designing and building RESTful APIs, touching on important aspects such as CRUD operations, authentication, documentation, testing, and collaboration with front-end teams. However, there are areas where you could enhance your answer to make it more impactful.

Strengths:

1. Context: You specified that you work on RESTful APIs regularly, which establishes your experience.
2. CRUD Operations: Mentioning the conventions for HTTP methods (POST, PUT, GET) shows you have a good understanding of REST principles.
3. Security Considerations: Discussing authentication and authorization indicates awareness of security, which is crucial in FinTech.
4. Documentation: Using Swagger UI for API documentation highlights your approach to transparency and ease of use for other teams.
5. Testing Practices: Emphasizing testing with RSpec ensures that your APIs are reliable and robust.

Areas for Improvement:

1. Detail: Providing examples or specific projects where you implemented these APIs can add credibility to your experience.
2. Design Patterns: Mentioning any design patterns you used (like MVC, or services) would showcase a deeper understanding of software architecture.
3. Performance & Scalability: Briefly discussing how you approached performance optimization or scalability would reflect your awareness of real-world applications.
4. Error Handling: Including how you handle errors and provide meaningful responses could enrich your answer.

Rating: 4/5

In summary, while your answer covers essential components, incorporating real-world examples and addressing additional topics like design patterns and error handling would strengthen it further. Remember to balance technical details with clarity to convey your experience effectively.

How have you integrated external services like Salesforce or Auth0 in your previous projects?

To be honest, I don't have expeirence integrate with Salesforce and Auth0,
However from my research, there integration documents are quite good and the ruby community also has the libraries and the articles to helping the section so I think I could prepapre well for that. as last time in my previous company they asked me to build the plan to integrate with Stripe and I finished that one time.

Your answer acknowledges a lack of direct experience with Salesforce and Auth0, which is honest. However, it could be improved to better demonstrate your problem-solving skills and adaptability. While it's good to mention your research and preparation capabilities, you could enhance your response by focusing more on transferable skills and past experiences that relate to integration tasks.

Here’s a breakdown of your answer:

1. Honesty: Being honest about your experience is commendable. However, you should also emphasize your willingness and ability to quickly learn and adapt to new technologies.

2. Research and Resources: While mentioning research on integration documents and community support is valuable, it would be more convincing if you included specific strategies or steps you would take to learn and implement the integration.

3. Past Experience: The mention of your experience integrating with Stripe is relevant and demonstrates a hands-on capability. However, you could expand on that to explain how you approached that integration, what challenges you faced, and how you resolved them.

4. Confidence: Although showcasing your willingness to learn is vital, it’s also important to communicate confidence in your problem-solving abilities and technical skills.

To improve your answer, consider incorporating these elements:

- Discuss methodology: Describe a systematic approach to integration projects (e.g., understanding API documentation, creating prototypes, testing).
- Share results: Mention the impact or outcomes of your previous integrations, such as improved efficiency or user experience.
- Connect to the fintech domain: Link your understanding of legal/compliance issues concerning user authentication (for Auth0) or CRM capabilities (for Salesforce).

Rating: 3/5.

You have a solid foundation, but incorporating more specific examples and demonstrating a deeper understanding of the integration process can significantly enhance your response.

What strategies do you use for maintaining high availability and security in your applications?

In term of high availability, I prioritize building the app with high performance which normally follow the standards of the response time should be under 3s, and the query. should be under 1 seconds unless it has any specification reason, build the app so we can horizontal autoscale, have the proper failover mechanism like apply loading balancing to the applicaiton
using feature flag for rerelase and testing,
and building a site to monitoring like granfana or datadog and integrate with sentry to be awere of the issue happen
Security:
Follow the best practice in the code to prevent some of the common issue such cross site attach, sql injection
configure the server to prevent DDOS like apply rate limit
add multiple layer security controls intead of single layer
Audit and do pentesting regularly to proactive identify and fix the security issue
Apply the TSL to the server is a basic security standards
Monitioring security building tool for early detect the security issue
Got security check list within the code PR and code review

Your answer addresses the key aspects of high availability and security effectively, covering multiple strategies and best practices. Here's a breakdown:

1. High Availability: You mentioned critical performance metrics, autoscaling, and load balancing. This shows a strong understanding of ensuring system performance and resilience. However, you could further elaborate on disaster recovery plans, usage of multiple availability zones, and the importance of redundancy (e.g., using microservices) to enhance these strategies.

2. Security: You covered several important areas, including securing code against common vulnerabilities, implementing layers of security, and conducting regular audits. Mentioning specific frameworks or standards, such as OWASP, could strengthen your answer. Additionally, discussing the importance of encryption for sensitive data and user authentication methods (like OAuth) would also be beneficial.

3. Monitoring: Your points on monitoring using tools like Grafana, Datadog, and Sentry highlight your proactive approach to both performance and security. Expanding on setting alerts for critical metrics can show a deeper understanding of maintaining system health.

To improve your answer:

- Structure your response more clearly by explicitly separating high availability and security into distinct sections.
- Provide concrete examples or scenarios where you have implemented these strategies in your past experiences.
- Use precise terminology to convey your expertise more effectively, especially in a senior engineering context.

Overall, your answer demonstrates a solid foundation, but with enhancements in detail and structure, it can become more impressive.

Rating: 3.5/5