Is it legal to ask about salary expectations or current salary in Switzerland?

You may ask what salary they expect going forward. Asking what they currently earn is becoming less common and some cantons discourage it (e.g. Geneva has guidelines against it). A lawyer in your canton can confirm the exact rule. Better practice: you state the budget first and ask if it matches their expectation.

Can I ask about gaps in their CV or reasons they left previous jobs?

Yes, this is normal and legal. Ask neutrally—'Tell me what you were doing between 2021 and 2022'—and listen. Illness, caregiving, or retraining are common reasons and are not red flags. If something seems off, ask a follow-up. You cannot ask about health in detail.

Should I ask about willingness to work evenings or on-call support?

Yes, ask directly: 'This role includes [on-call / evening standby]. Are you available for that?' Check your industry's norms and any applicable GAV (collective labour agreement). Factor on-call into the total compensation. Be clear about frequency and compensation before they accept.

Interview Questions for Backend Developer

Hiring a backend developer requires testing both technical depth and communication skills. Use targeted questions grouped by competency—architecture decisions, debugging approach, system design—and watch for candidates who explain their reasoning clearly and adapt to feedback. This guide helps Swiss employers assess candidates fairly without legal risk.

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Backend developer roles demand strong foundational skills in databases, APIs, and deployment. A good interview reveals not just what they know, but how they think under pressure and collaborate with others.

The questions below are grouped by what they test. For each group, we show what strong and weak answers look like. Pay attention to answers that show real projects, not textbook knowledge.

Technical Foundation & System Design

Ask questions that reveal how a candidate approaches architecture. Listen for concrete examples from their own work, not generic textbook answers. A strong answer names tradeoffs—why they chose SQL over NoSQL, or vice versa.

Avoid asking them to code on a whiteboard under time pressure unless coding speed is central to the role. A 30-minute at-home task or code review conversation works better.

Tell me about a database schema you designed. What would you change if traffic doubled?
Walk me through how you'd design an API endpoint for [realistic scenario]. What would fail first under load?
Describe a time you refactored legacy code. How did you decide what to touch?
When would you use caching? Tell me about a project where it mattered.
What's a system you've built that had to scale? How did monitoring help you spot problems?

Problem-Solving & Debugging

Technical skill alone isn't enough. Test how they isolate problems, ask clarifying questions, and learn from failure. A weak answer blames tools or teammates. A strong answer shows curiosity and systematic thinking.

Candidates who say 'I don't know' and then ask a smart follow-up question are often stronger than those who guess.

Tell me about a bug that took you days to find. How did you finally solve it?
Production is slow. Walk me through how you'd investigate.
You inherit code with no tests. How do you make it safer without breaking it?
Describe a time your solution didn't work. What did you do?
What's your process for learning a new framework or language?

Teamwork, Communication & Swiss Context

Backend developers often work alone, but they need to explain choices to non-technical managers and integrate with frontend or DevOps teams. Test for clarity and openness to feedback.

For Swiss roles, ask about remote-work expectations, willingness to join standups, and how they handle written communication (many Swiss teams work asynchronously across cantons or time zones).

Tell me about a time you disagreed with a colleague's code decision. How did you handle it?
How do you explain a technical constraint to a non-technical stakeholder?
What Pensum (hours per week) are you looking for, and do you prefer office days or mostly remote work?
Have you worked in teams using Scrum, Kanban, or Agile practices? What worked for you?
Describe your experience with code review. Do you prefer giving or receiving feedback?

Frequently asked questions

Is it legal to ask about salary expectations or current salary in Switzerland?: You may ask what salary they expect going forward. Asking what they currently earn is becoming less common and some cantons discourage it (e.g. Geneva has guidelines against it). A lawyer in your canton can confirm the exact rule. Better practice: you state the budget first and ask if it matches their expectation.
Can I ask about gaps in their CV or reasons they left previous jobs?: Yes, this is normal and legal. Ask neutrally—'Tell me what you were doing between 2021 and 2022'—and listen. Illness, caregiving, or retraining are common reasons and are not red flags. If something seems off, ask a follow-up. You cannot ask about health in detail.
Should I ask about willingness to work evenings or on-call support?: Yes, ask directly: 'This role includes [on-call / evening standby]. Are you available for that?' Check your industry's norms and any applicable GAV (collective labour agreement). Factor on-call into the total compensation. Be clear about frequency and compensation before they accept.

General information for Swiss employers, not legal advice. Have a lawyer confirm anything with legal consequences.