Required Skills & Tech Stack
Spring Boot
Java
Bootstrap
Backend
Backend Development
Development
Java Development
React.js
📚 Free Study Materials (4)
📖
Aptitude Practice Questions & Mock Tests
Open Resource ↗
Curated logical, quantitative, and verbal reasoning problems for the initial online screening round.
🎯
Company-Specific Interview Preparation Corner
Open Resource ↗
Detailed interview experiences, exam formats, and previous test questions for Opus Technologies and tech roles.
📝
Technical Placement Cheat Sheets & Question Bank
Open Resource ↗
High-yield coding cheat sheets, core CS fundamentals (OOP, DBMS, OS, Networks), and rapid revision guides.
💻
Algorithm, DSA & Live Code Debugger Practice
Open Resource ↗
Hands-on problem sets to improve coding speed and step-by-step memory debugging.
Eligibility Criteria
Experience: 3-8 Yrs. Open to matching qualifications.
Selection & Interview Process
1
Online Assessment / Technical Interview Rounds / HR Review
Job Description & Key Responsibilities
Overview We are looking for a Senior Fullstack Developer to drive our customer experience strategy forward by consistently innovating and problem-solving. Our solutions are built on the Digital Network Architecture, around Cloud Native principles and in a Scaled Agile Framework. The ideal candidate is passionate about the customer experience journey, highly motivated, intellectually curious, analytical, and possesses an entrepreneurial mindset. The Role • Senior Developer with adequate skills and experience delivering design/code of high quality • Drive design and development in Java 8 and above using Object Oriented SOLID principles and patterns towards creating reusable and scalable microservices leveraging technologies such as Spring Boot Framework, and Event Driven Architecture. • Strong experience in react.js • Leverage the appropriate persistence mechanisms such as RDBMS, No SQL etc based on needs • Implement Coding Best Practices. Implement Code Quality gates as per the program norms. • Perform various Proofs-of-concept depending on the business needs • • Exhibit teamwork aligned completely with the Agile environment • Provide technical mentoring/training for junior developers based on the needs All About You • Passionate about technology, with strong Object-Oriented Design & Programming skills • In depth knowledge on product development • Strong expertise in Java and Spring Boot and ReactJS. Experience working on Event Driven Architecture would be an advantage. • Experience in Online / Real Time Systems development • Experience in Cloud based development is desirable • Strong Communicator • Quick grasping and learning abilities • Technical Mentoring Skills
Preparation Hub
Opus Technologies — Software Engineering & Full Stack Interview Guide
Previously asked questions, exam syllabus, coding benchmarks & round strategy.
📖 Previously Asked Questions & Preparation Links
APTITUDE & LOGIC
📖
Aptitude Practice Questions & Online Mock Tests
Curated logical, quantitative, and verbal reasoning problems to sharpen reasoning skills required for the initial screening test.
Open Resource ↗
COMPANY GUIDE
🎯
Opus Technologies Interview Preparation Corner
Comprehensive guide covering typical interview formats, common questions, and preparation tips for Opus Technologies and off-campus tech roles.
Open Resource ↗
MOCK TESTS & PAPERS
📝
Comprehensive Interview Prep Resources & Syllabus
Collection of previous year questions, company-specific test patterns, and interview experiences for technical and HR rounds.
Open Resource ↗
CODING PRACTICE
💻
Algorithm and Data Structure Problem Set
Practice problems to improve coding proficiency and algorithm problem-solving speed for technical rounds.
Open Resource ↗
💻 Previously Asked Coding Challenges
Easy / Medium
⚡ Live Debugger
Two Sum & Two Pointers Array Optimization
Asked in 85% tech rounds
Medium
⚡ Live Debugger
Reverse Linked List & Detect Cycle (Floyd's Algorithm)
Frequently asked in core rounds
Medium
⚡ Live Debugger
SQL Nth Highest Salary with DENSE_RANK() & Subqueries
Top standard database question
Easy / Medium
⚡ Live Debugger
Valid Parentheses & Stack Implementation
Standard online assessment problem
🗺️ Round-Wise Strategy
Round 1: Online Assessment (OA)
Aptitude, Quantitative Logic & 2 Coding Problems
Focus on accuracy and speed. Practice arrays, strings, and standard arithmetic puzzles.
Round 2: Technical Interview 1
Core Tech Stack (Spring Boot, Java, Bootstrap, Backend, Backend Development, Development, Java Development, React.js) & Live Code Tracing
Explain your thought process aloud. Analyze time & space complexities before coding.
Round 3: System Design & Problem Solving
Database Schemas, APIs & Architecture Basics
Clarify edge cases, diagram schemas cleanly, and discuss scalability trade-offs.
Round 4: HR & Cultural Fit Discussion
Opus Technologies Core Values, Learning Agility & Offer Terms
Demonstrate passion, strong communication, and readiness for full-time collaboration.
❓ Core Technical Questions & Answers
Explain OOP (Object-Oriented Programming) principles with real-world examples in Spring Boot. Answer ▼
Model Answer: 1. Encapsulation (data hiding via private fields/getters). 2. Abstraction (hiding implementation complexity). 3. Inheritance (code reusability). 4. Polymorphism (method overriding/overloading).
What is the time and space complexity of QuickSort vs MergeSort? Answer ▼
Model Answer: QuickSort: Average O(N log N) time, O(log N) space. Worst O(N^2). MergeSort: Guaranteed O(N log N) time, but requires O(N) auxiliary space.
Explain the difference between SQL Indexing (B-Tree vs Hash) and when not to use an index. Answer ▼
Model Answer: Indexes speed up SELECT queries via B-Trees. However, they slow down INSERT, UPDATE, and DELETE operations because indexes must be updated on disk. Avoid on low-cardinality columns (e.g., boolean flags).
What happens under the hood when you enter a URL in a browser? Answer ▼
Model Answer: 1. DNS lookup (resolves IP). 2. TCP 3-way handshake (SYN, SYN-ACK, ACK). 3. TLS negotiation for HTTPS. 4. HTTP GET request sent. 5. Server responds with HTML/CSS/JS. 6. Browser renders DOM & CSSOM tree.
What is the difference between REST and GraphQL APIs? Answer ▼
Model Answer: REST uses multiple fixed endpoints with possible over/under-fetching. GraphQL uses a single endpoint allowing clients to query exact fields in a single request.
🤝 Behavioral & HR Questions (STAR Method)
Why do you want to join Opus Technologies as a Java Developer?
Preparation Tip: Highlight Opus Technologies's market reputation, recent tech innovations, and how your skills in Spring Boot directly solve their team's objectives.
Describe a challenging bug or academic project roadblock and how you resolved it.
Preparation Tip: Use the STAR method: Situation (project context), Task (what needed solving), Action (specific tools/logic applied), Result (quantifiable positive outcome).
How do you handle strict deadlines or sudden scope changes?
Preparation Tip: Explain your prioritization strategy, proactive communication with mentors/peers, and agile mindset.
