Avalara India Site Reliability Engineer Interview: Rounds, Questions and Preparation

What the job involves

Site Reliability Engineers (SREs) at global tech companies like Avalara India ensure that large-scale, distributed systems are reliable, scalable, and efficient. They combine software engineering and systems administration to build automation, monitor services, and respond to incidents. Day to day, they write code to improve infrastructure, set up observability, and collaborate with development teams to maintain service level objectives.

Role and Technical Knowledge

1. 1

   What is the difference between a Site Reliability Engineer and a DevOps Engineer?

   Highlight that SRE focuses on reliability, SLOs, and error budgets, while DevOps is a broader culture and practice. Mention that SRE applies software engineering to operations problems.

2. 2

   Explain the concept of Service Level Objectives (SLOs) and Service Level Indicators (SLIs).

   Define SLI as a measurable metric (e.g., latency, error rate) and SLO as a target for that metric. Explain how error budgets are derived from SLOs and used to balance reliability and feature velocity.

3. 3

   How does Linux memory management work, and what tools would you use to troubleshoot a memory leak?

   Cover virtual memory, paging, and OOM killer. Mention tools like top, free, vmstat, and ps, and how to identify processes with growing memory usage.

4. 4

   What happens when you type a URL into a browser and press Enter?

   Walk through DNS resolution, TCP handshake, HTTP request/response, and rendering. Emphasize the networking and system components relevant to SRE.

Practical Scenarios

1. 5

   A service is experiencing high latency. How would you troubleshoot and resolve the issue?

   Outline a systematic approach: check monitoring dashboards, identify the bottleneck (CPU, memory, network, database), review recent changes, and apply mitigations like scaling or rollback.

2. 6

   You need to deploy a new version of a microservice with zero downtime. What strategy would you use?

   Discuss blue-green deployment or canary releases, health checks, and rollback plans. Mention using Kubernetes or load balancers to route traffic gradually.

3. 7

   How would you set up monitoring and alerting for a web application?

   Cover key metrics (latency, error rate, throughput, saturation), tools like Prometheus and Grafana, and setting meaningful alerts based on SLOs to avoid alert fatigue.

4. 8

   Describe how you would automate the scaling of an application based on load.

   Explain horizontal pod autoscaling in Kubernetes or auto-scaling groups in AWS, using metrics like CPU or custom metrics, and the importance of testing scaling policies.

Behavioural and HR

1. 9

   Tell me about a time you faced a critical technical issue and how you handled it.

   Use the STAR method: describe the situation, your task, actions taken, and the result. Highlight communication, teamwork, and learning from the incident.

2. 10

   How do you prioritize tasks when multiple incidents occur simultaneously?

   Emphasize assessing impact and urgency, using triage, and communicating with stakeholders. Mention following runbooks and escalating when needed.

3. 11

   Why do you want to work as a Site Reliability Engineer, and why our company?

   Show passion for reliability and automation, and research the company's tech stack and culture. Connect your skills and career goals to the role.

4. 12

   Describe a time you worked in a team to achieve a goal. What was your role?

   Focus on collaboration, your specific contributions, and how you handled conflicts or differing opinions. Highlight the outcome and what you learned.

Coding and Automation

1. 13

   Write a Python script to check if a website is up and alert if it is down.

   Use requests library to send HTTP GET, check status code, and use smtplib or a webhook for alerts. Include error handling and logging.

2. 14

   How would you parse a large log file to find the top 10 IP addresses with the most requests?

   Use command-line tools like awk, sort, uniq, and head, or write a Python script with dictionaries and counters. Discuss efficiency for large files.

3. 15

   Explain how you would use Infrastructure as Code (IaC) to manage cloud resources.

   Mention tools like Terraform or AWS CloudFormation, benefits of version control and reproducibility, and how to structure modules and environments.

4. 16

   What is a CI/CD pipeline, and how would you design one for a microservices application?

   Describe stages: build, test, deploy, and monitor. Mention tools like Jenkins, GitLab CI, or GitHub Actions, and include automated testing and rollback strategies.