Ciena SDE-1 Interview Experience (Gurgaon) – Technical Round 1
Summary
I recently interviewed with Ciena for an SDE-1 (Java Developer) role in Gurgaon. The technical round covered a mix of DSA, Java, Spring Boot, SQL, and system concepts, with a particular focus on Java and Spring Boot.
Full Experience
The round was a mix of DSA + Java + Spring Boot + SQL + System concepts. But was more focused on java and springboot.
🧠 DSA Questions
1. Longest Substring Without Repeating Characters
Example: abcac → abc → Output: 3
2. Merge Two Sorted Linked Lists
l1: 1 → 3 → 5
l2: 2 → 4 → 6
☕ Java + Spring Boot
Questions asked:
- Difference between
@RestControllervs@Controller - Create a sample API
- Common Spring Boot annotations and how springboot application starts (he was expecting to mention all the annotations)
🗄️ SQL Questions
1. Find second highest salary
2. A follow up question, find second highest unique salary
3. Flip binary values
Table: BINARY_TABLE
0
1
0
Solution:
UPDATE BINARY_TABLE
SET Binary_Column = 1 - Binary_Column;
⚙️ Core Java Concepts
- Java 8 features (Streams, Collections)
- How
HashMapworks internally
📡 Kafka & System Concepts
- Kafka basics
- Partitions and consumers
- Handling high traffic scenarios
Interview Questions (13)
Longest Substring Without Repeating Characters
Given a string, find the length of the longest substring without repeating characters. Example: abcac → abc → Output: 3
Merge Two Sorted Linked Lists
Given two sorted linked lists, merge them into a single sorted linked list. Example: l1: 1 → 3 → 5, l2: 2 → 4 → 6
Difference between @RestController vs @Controller
Explain the key differences between Spring's @RestController and @Controller annotations.
Create a Sample REST API
Design and outline how to create a sample REST API, possibly using Spring Boot.
Spring Boot Annotations and Application Startup Process
Describe common Spring Boot annotations and explain the internal process of how a Spring Boot application starts up, mentioning all relevant annotations.
Find Second Highest Salary
Write a SQL query to find the second highest salary from a table.
Find Second Highest Unique Salary
Write a SQL query to find the second highest unique salary from a table.
Flip Binary Values in a Table
Given a table BINARY_TABLE with a column containing binary values (0 or 1), write a SQL query to flip these values (0 becomes 1, 1 becomes 0).
Table: BINARY_TABLE
0
1
0
Java 8 Features (Streams, Collections)
Discuss the significant features introduced in Java 8, specifically focusing on Streams API and enhancements to the Collections framework.
Internal Working of HashMap
Explain the internal data structures and algorithms that power Java's HashMap.
Kafka Basics
Explain the fundamental concepts and architecture of Apache Kafka.
Kafka Partitions and Consumers
Discuss Kafka partitions, their purpose, and how consumers interact with them to process messages.
Handling High Traffic Scenarios
Describe architectural patterns, strategies, and considerations for designing systems that can effectively handle high traffic and scale accordingly.