First step is a task to test programming skills in Java, followed by 5 to 6 rounds of interviews including HR, team, cultural, and meeting with CEO. The tasks are of moderate difficulty.
Interview questions [1]
Question 1
General questions regarding ambitions, previous experiences, etc.
I applied online. I interviewed at Sonar (Geneva) in Nov 2025
Interview
1. Codility Test
2. Initial Video Interview (30mins): A brief conversation with HR representative to discuss your background, goals, and motivations.
3. Technical interview (30 mins): Despite completing the technical interview and leaving the session feeling confident, I was informed at the end of the interview that they would not be moving forward before the scheduled sprint stages began.
4. 2-hour Technical Interview
5. 30-minute Cross-functional Interview
6. 20-minute Final Interview with an Engineering Leader
Interview questions [1]
Question 1
Codility:
1. Nails and hammer problem: review code and make max 4 fixes. Hammer down at most K nails (maximize the n of nails that end up having the same length)
2. Remove adjacent pairs (a/b and c/d): CBACD -> CBA -> C
3. Binary reduction to zero: if v is odd, subtract 1, if even, divide it by 2 n of operations? 011100 (28) -> 11100 (28) -> 14 -> 7 -> 6 -> 3 -> 2 -> 1 -> 0 (7ops)
Technical Interview Questions:
1. Refactoring a Java code snippet: encapsulation, structure, alternative designs.
2. Discussing API usage: which requests to use, sending data in GET requests.
3. Scalability considerations: handling multiple requests, caching, load balancing.
4. Handling nested conditionals and improving code readability.
5. Explaining your approach, thought process, and code decisions throughout the exercises.
Behavioral / Situational Questions:
1.Describe a time a colleague raised a concern about your work and how you addressed it.
2.Explain a situation where you introduced a bug and how you identified and resolved it.
3. Share an example of a challenging situation and how you managed it.
There is usually a first online screening, followed by a short conversation with a recruiter, and then a first technical interview. After that, there is an interview on-site and the people and culture interview.
Interview questions [2]
Question 1
What is the difference between checked and unchecked exceptions?
What are the various collections available in the Java standard library? What are their uses cases? What is the complexity of typical operations and why?
