Harness

Role: Senior Software Development Engineer (Backend)

College: Not Specified

Interview Date: April 2025

Interview Type: Off-Campus

Result: Selected (Implied, as the post is a guide based on a successful experience)

Difficulty: Hard (Overall process)

Rounds: 4

Topics Asked: Data Structures, Algorithms, Low-Level Design, Java, Spring Boot, High-Level Design, Concurrency, Behavioral Questions

Experience:

The candidate applied through a referral for a Senior SDE (Backend) role and received an HR call, initiating the interview process.

Round 1: DSA - Strong Hire (1 hour, Virtual): This round involved two problems (1 hard + 1 medium). The candidate chose C++. The focus was on optimized, bug-free, syntactically correct code, time and space complexity analysis, and dry-running code with edge cases. The candidate started with brute-force, then moved to optimized solutions, coded them, and walked through edge cases and complexities.

Round 2: Low-Level Design - Strong Hire (1 hour, Onsite - Whiteboard): This round involved one LLD question. Expectations included deep requirement gathering, clarification questions, a well-thought-out class diagram (entities, functions, functionality logic), and adherence to design principles and patterns. No coding was required. The candidate found this to be the most enjoyable round, with dynamic discussion and encouragement for back-and-forth on the design. Many questions were asked to understand design depth and thought process.

Round 3: DSA + Java - Lean Hire (1 hour, Virtual): This round focused on proficiency in Java + Spring Boot, along with DSA. It also required optimized, bug-free code (candidate used C++), code dry-run, and complexity analysis. The candidate found this round the toughest due to being low on energy after a packed day. They "nailed the first problem" but struggled with the second, despite hints from the interviewer, feeling a performance dip.

Round 4: High-Level Design + Behavioral (1 hour, Virtual): This round began with a discussion on API design, followed by a small LLD problem (designing a small app feature, with most discussion on handling concurrency). It concluded with core Java and behavioral questions. This round was a mix of technical and soft skills, and the candidate also had the opportunity to ask questions about Harness's culture and team structure.

Overall Experience: The candidate noted the lack of detailed information online for Senior SDE roles at Harness and aimed to create a guide. They highlighted the importance of energy management during the process.