Airtel

Role: Software Development Engineer 2 (SDE-2)

College: Not Specified

Interview Date: 2025-11-09

Interview Type: Virtual (Google Meet)

Result: Not Specified

Difficulty: Hard

Rounds: Not Specified

Topics Asked: Java, Spring Boot, Kafka, System Design, Monitoring, SLAs.

Experience:

The interview process for the SDE-2 position at Airtel focused heavily on problem-solving, backend design, and real-world system performance. The panel emphasized hands-on experience, particularly with Java, Spring Boot, Kafka, and monitoring tools.

Round 1: Technical Deep Dive (~90 minutes)
This round was conducted by a Senior Engineer and a Tech Lead. It started with a quick introduction and then moved directly to technical discussions.

• Kafka Fundamentals: Questions included explaining how Kafka ensures message delivery guarantees (At-most-once, At-least-once, Exactly-once). The candidate mentioned practical knowledge by citing Kafka configurations like `acks=all`, `min.insync.replicas=2`, and `enable.idempotence=true`.
• Monitoring and Observability: The interviewer asked how to track production system performance and uptime. The candidate's approach involved Grafana + Prometheus for metrics visualization, AWS CloudWatch for infrastructure-level alerts, and ELK Stack for centralized log management. They also mentioned configuring Grafana alerts for latency spikes and downtime anomalies.
• API SLAs and Performance: Questions were asked about what an SLA for an API is and how to ensure it's met. The candidate defined SLA in terms of uptime, response time, and error tolerance.

Key learnings from this experience include that Airtel's interviews are scenario-driven, not purely theoretical, with an emphasis on real-world debugging, monitoring, and SLAs. Kafka and System Design knowledge are highly valued, and candidates should expect a blend of coding and practical architecture questions.