My Complete Interview Journey (2024-2025)

Experience : 7+ Years
Education : B.E. (Information Technology), UIT RGPV Bhopal (Tier-3 College)
Location : Bengaluru
Current Role : Sr. Associate Projects @ Cognizant (Client: American Express)
Skills: Java, Golang, React, Spring Boot, Microservices, System Design, Kafka, PostgreSQL, Kubernetes

Complete Timeline
Phase 1: http://leetcode.com/discuss/post/5724980/help-needed-boeing-cognizantamex-capgemi-e2ae/

Phase 2: 2025 Job Search

Starting Point: Cognizant AMEX (₹28.7 LPA)
Interview Period: July 2025 - August 2025
Notice Period: 90 days

Publicis Sapient - Senior Software Engineer
Tech Stack: Java, Spring Boot

Round 1: Java & Architecture: Java basics and Java 8 features, Spring Boot annotations, Microservice architecture discussions, Saga Pattern (choreography vs orchestration), and a basic API design exercise.
Round 2: Agile & Process: Focused on Agile practices, delivery workflows, team ownership, and collaboration.

Result: OFFER - ₹30 LPA (with a verbal promise of ₹38 LPA closer to the end of my notice period, Gave the initial offer then ghosted me).

APTIV (WindRiver Division) - Software Engineer
Tech Stack: Golang

Round 1: Technical:
DSA: Search in sorted rotated array.
API Design: Library Management System (CRUD for books/categories).
Golang basics: syntax, slices, maps.

Round 2: Deep Dive:
Golang concurrency: goroutines, channels.
A deep dive into my American Express project architecture, explaining design choices and trade-offs.
Behavioral: Most complex problem solved (shared the Amex pipeline story), and work I'm most proud of.

Result: INITIAL OFFER made, but after discussing salary expectations → GHOSTED.

Walmart Global Tech - Senior Software Engineer
Tech Stack: Java, Spring Boot

Interview Date: All rounds on the same day (9:30 AM - 4:00 PM IST)

Round 1: DSA:
Longest Common Prefix.
Rotate Array by K without extra memory.

Round 2: System Design - Notification System:

My Solution: Kafka-based event pipeline for scalability, idempotency using a notification ID, consumer groups for each channel (Email, SMS, Push), retries with exponential backoff + Dead Letter Queue for failures, Load Balancer + API Gateway as an entry point, DB schema (notification_id, status, priority, scheduled_ts), and API design (/v1/userRequests, /v1/reports).

Round 3: Low Level Design:

Extended the notification system with design patterns: Strategy Pattern for multiple notification channels, Retry Pattern with Resilience4j, and Observer Pattern for event listeners.

Round 4: Hiring Manager:

Behavioral questions (conflict handling, deadline pressure), a deep dive into my Amex data pipeline architecture, and project trade-offs/design decisions.

Result: OFFER ACCEPTED - ₹52.43 LPA (Target Total Pay as per offer letter). Breakdown: Annual Base Pay (₹35L) + Target Bonus (₹7L) + Target Stock (₹8.75L) + Retirals (₹1.68L). Joining September.

NetApp - Software Engineer 3
Tech Stack: Golang, React

Round 1: Mixed Technical:
HTTP request flow in Kubernetes (explained 200/403/500 responses).
PostgreSQL LISTEN/NOTIFY (discussed pgx.WaitForNotification for migrations).
API Design: Library Management System with CRUD operations.
DSA: Word occurrence in a sentence

Round 2: Golang & React:

Golang concurrency patterns (goroutines, channels), PostgreSQL FOR UPDATE SKIP LOCKED for migration handling.
React: Write textbox autofocus code (struggled with this).
DSA: Longest Substring Without Repeating Characters.

Round 3: Advanced Topics:

Golang design patterns; Inheritance in Go (Couldn't answer properly).
React: hooks, context vs redux, React 19 new features.
DSA: Spiral Matrix - Solved with interviewer hints.

Round 4: Hiring Manager:

Distributed team challenges, conflict resolution, role expectations, and project fit.

Result: OFFER - ~₹51.24 LPA (₹41.8L Base + ₹3.34L Bonus + ~$7.3K RSUs/year). Declined for Walmart.

Money Forward - Senior Fullstack Engineer
Tech Stack: Java, Spring Boot, React
Location: Chennai

Round 1: Basics: Java OOPs concepts, Spring Boot controllers/annotations, DSA (First non-repeating character in a string - Solved).

Round 2: System Design - Attendance Management System:

My Solution: Kafka for clock-in/out events (async), DB sharded by office ID, caching for manager dashboard, WebSockets for ≤5s staleness, and report generation to S3 with pre-signed URLs.

Feedback - Areas I missed: Cache invalidation strategy not properly defined, should have handled duplicate events with idempotent consumers, needed a dedicated worker service for report generation.

Round 3: Hiring Manager: Scenario-based questions on mentoring, team motivation, and how my technical trainer experience helps in development.

Result: ON HOLD (They mentioned they would get back to me if they couldn't find another candidate).

Visa - Staff Software Engineer (Cybersecurity + AI)

Round 1: DSA:

Cycle Detection in Linked List: Solved in <5 minutes with edge cases.
Combination Sum III: Attempted in Go, partial solution, couldn't complete due to debugging issues. This was the critical miss.

Round 2: System Design - Twitter-like Feed:

My Solution: Services (User, Post, Feed, Follower), DB (Postgres, Cassandra, Redis), Pipeline (Kafka + Flink for async fanout), CDN for media, and Auth (OAuth2.0, API Gateway, LB, SSL/TLS). Also explained caching hot posts and inverted indexes for search.

Result: REJECTED - Likely due to the incomplete DSA solution in Round 1.

Visa - (Cybersecurity Team - Second Opportunity)
Visa contacted me again for another position with the cybersecurity team.
Round 1: DSA
Minimum Window Substring (LeetCode Hard) - Solved.
Round 2: Security Deep Dive
Intensive questions on security concepts: encryption, TLS, mTLS, certificates, HSM, detailed breakdown of how HTTPS works, Istio, and questions on my experience.
Result: After this round, they wanted to give me a CodeSignal assessment. I declined as it was in my last week of job search and I had already decided to join Walmart.

JP Morgan Chase - Senior Software Engineer
Tech Stack: Java, React, SQL

Round 1: Mixed Technical:
DSA - 3rd largest element: Solved in O(n). Interviewer asked for a Java 8 Streams version, and I blanked on the syntax.
SOLID principles & Singleton pattern with double-checked locking explained.
SQL - 2nd highest salary: Major failure here. I didn't know RANK() or DENSE_RANK() and failed to get the correct result with other methods.
What I tried (WRONG):
WITH ranked_salaries AS (
SELECT salary, ROW_NUMBER() OVER (ORDER BY salary DESC) as rn
FROM employees )
SELECT salary FROM ranked_salaries WHERE rn = 2;

Result: REJECTED - The SQL knowledge gap was the primary reason.

Practo - Software Engineer
Tech Stack: Java, Spring Boot

Round 1: DSA: Maximum Subarray Sum & one more easy LeetCode problem - Solved.
Round 2: Mixed: DSA (Maze Path BFS - Solved), LLD (Strategy Pattern), Java 8 Streams, and SQL queries.
Round 3: System Design - Notification Service:
Requirements: Multiple channels, scheduled notifications, priority delivery, retries, status tracking, scale to 10M/day.
My Solution: APIs, DB Schema (indexed + sharded), Flow (LB → Service → Kafka topics), Retry (@Retryable + DLQ), auto-scaling consumers, and idempotency.

Result: REJECTED - No feedback provided.

Detailed Preparation

Technical Preparation:
Java & Spring Boot: "Concept and Coding" YouTube playlists, Baeldung articles, and hands-on projects.

System Design:
LLD: "Concept and Coding" LLD playlist, and implemented Design Patterns myself.
HLD: Followed "Concept and Coding," "Jordan has no life," igotaoffer, and hellointerview.
Data Structures & Algorithms: Practiced all topics from the LeetCode main page.
Behavioral: Used the STAR pattern for all responses.