Ho presentato la mia candidatura online. Ho sostenuto un colloquio presso Intelcom | Dragonfly nel mese di nov 2025
Colloquio
3-round process: HR screening (15min), Technical round with algorithms/OOP/design patterns (60min), System design round covering frontend performance and backend service architecture (60min). Collaborative environment, interviewers were friendly. Remote interview via Teams. Process took 2 weeks total.
Domande di colloquio [1]
Domanda 1
1. Algorithms & Data Structures
Solve an array rotation problem - rotate an array to the right by k steps in O(n) time and O(1) space
2. Object-Oriented Programming (OOP)
- Explain OOP concepts - abstraction, encapsulation, inheritance, and polymorphism
- How do you implement inheritance in JavaScript/TypeScript?
- What is dependency injection and how does it help in decoupling code?
- How do you achieve decoupling between two classes?
3. Design Patterns
- Do you know design patterns? Explain a few common ones
- Explain the Factory design pattern in detail
- Implement a Factory pattern for an ETL system that handles multiple data sources (SQL, CSV, API). Show the code
4. Software Design Principles
- What coding principles do you follow while developing ?
5. Databases
- Have you worked with NoSQL databases? Which ones?
- How do you choose between SQL and NoSQL when designing an application?
- What database would you choose for the dashcode service - SQL or NoSQL? Why?
6. APIs (REST/GraphQL)
- Have you worked with GraphQL? When do you prefer GraphQL vs REST APIs?
- What best practices do you follow when developing REST APIs?
7. Authentication & Security
- What authentication methods have you implemented in your applications?
8. DevOps & CI/CD
Do you have experience with DevOps and building CI/CD pipelines?
9. Frontend Development (React)
- How do you implement virtualization for rendering large datasets efficiently?
- How do you avoid prop drilling and unnecessary re-renders in React?
- How do you maintain cache state on the client side to avoid making too many backend calls?
10. System Design - Frontend (Dashboard)
- Design a real-time dashboard that displays millions of order records with filters (date, status, city). How do you handle the data on the frontend?
11. System Design - Backend (Dashcode Service)
- Design a "Dashcode Service" - a secure code generation and validation system for package delivery. Explain the high-level architecture, components, tech stack, and API design
- How do you ensure unique code generation with no collisions when handling millions of concurrent requests?
12. Performance & Scalability
- The dashcode service receives 500K-1M requests per day. How do you improve performance and handle high traffic?
- How do you scale the dashcode application at the cluster level?
- Explain your approach to horizontal scaling, load balancing, and multi-AZ deployment
Ho presentato la mia candidatura online. La procedura ha richiesto 2 settimane. Ho sostenuto un colloquio presso Intelcom | Dragonfly nel mese di gen 2025
Colloquio
When you get interview with them, be careful.
1. The entire procedure was ambiguous. They put the home test round at the end of the interview ??!!, and did a round for something like general IT knowledge. That are 2 red flags because I never want to do home test, as well as nobody ever left the home-test round at the end
2. There were around 4 rounds: 1. HR interview 2. Team lead interview 3. Take home test 4. 2nd interview to explain. I stopped at round 2, when they brought 2 people in, different fields to ask me. Then they dropped although I believe I made a good response. After the end of meeting for 1 hour, they told me that the position was filled. Well, while I feel like it's kinda disrespectful, I think they are very familar with that action. Another point is that I can guess they want charismatic and native people, or someone referred by an internal employee.
2. As I said above, they did not respect candidate's effort, and wasted the time and resource for all.