Paytm

Role: Senior Software Engineer (SSE/SDE-2)

College: B.Tech from a Tier-2 college

Interview Date: November 2024

Interview Type: Off-Campus

Result: Selected (Offer)

Difficulty: Medium

Rounds: Hackerrank Online Assessment + 2 Technical Rounds

Topics Asked: Data Structures, Algorithms (strings, arrays, sliding window/two pointers for binary array with flips), System Design (scalability, monitoring, high-traffic systems, resource calculation), Project Discussion, Behavioral

Experience:

The candidate, with 3.5 years of experience as an SDE-2 at a banking company, applied via a direct application link and received a call from the recruiter within 1-2 hours.

Hackerrank Online Assessment (OA): The OA consisted of two coding problems:

• A medium-level problem based on strings.
• Finding the maximum even sum subsequence in an array.

Both questions required a clear understanding and efficient implementation of algorithms.

Round 1: Technical Round/DSA (1 hour): This round started with a basic introduction, followed by a DSA problem:

• A binary array of size n was given, and the candidate was allowed k flips (changing a 0 to 1). The task was to find the maximum length of consecutive 1s that can be formed.
• Follow-up: How to print the indices of the consecutive 1s after the flips.

Optimization strategies for both solutions and follow-ups were discussed. The interviewer focused on problem-solving skills and optimization.

Round 2: Technical + Behavioral Round (1.5 hours): This round began with a discussion about:

• The candidate's most interesting project and the challenges faced.
• System design, including scalability, monitoring, and handling high-traffic systems.
• Resource calculation to handle load spikes efficiently.
• Soft skills like dealing with stakeholders, explaining technical constraints, and aligning with business requirements.

The verdict was "Selected".