100 Interview Questions for Software Developers

This blog post is inspired by Jurgen Appelo 100 interview questions for Software Developers. I prefer to have a conversation instead of a knowledge test, so my questions do not have any correct answers. They should lead to conversation instead of validating knowledge.

Here we go.

Development Methods

How do you prefer to version control your code?
Do you follow any known patterns of version control?
What does continuous integration mean to you?
What is your definition of done?
How do you safely deliver code to production?
How do you make your production environment reproducible in test and dev?
How would you start troubleshooting an issue only visible in production?
Describe the steps involved for you to fix a bug
What is the importance of git commit messages and how do you format them?
How do you roll-back a failed deployment to production?
Production goes down because of a bad deployment. What would make you roll-back and what would make you roll-forward?
How do you manage assets that should not be committed to source control, like passwords or databases?
Where do you think code ownership should lie?
When should refactoring happen?
What code should be written by solitary programmers, and what code should be pair programmed or mob programmed?

Quality Assurance

What does quality mean for you?
How do you ensure quality in your delivery?
Who is testing your code?
What does testability mean to you?
What quality measures do you consider low hanging fruit?
Where do you draw the line between enough testing and too much testing?
Mention what statical code analysis tools you use
Do you write tests first, after or at the same time as the code?
What is your opinion on integration testing?
How do you deal with a test suite with brittle tests that require much maintenance?
How can you improve quality by communication?
How do you think that management can enable quality?
How do you measure quality?
What are your thoughts on technical debt?

Coding

What is your favorite language and why?
What do you consider a good framework?
What is your preferred way to document your code?
How do you make your code readable to others?
What do you consider maintainable code?
What are your most used development tools?
What is the worst feature of your favourite programming language?
What is the most common programming error people do?
How do you typically handle errors in your application?
Mention something you do to make your application secure.

DevOps

What’s your suggestion to improve deployment frequency?
What’s your suggestion to reduce time from you start working on a feature until its available to users?
What can we do to prepare for a system to be restored faster, when it goes down?
How would you propose we reduce number of releases that cause problems in production?
How do you verify the impact of your feature in production?
Where do you draw the line between development and operations?
How do you manage different configuration options for different environments?
How can you as a coder make your service easier to manage for operations?
What are the things that you believe should be automated?
What are the tools you need in order to deliver code to production once per day?
Do trunk-based development contribute to better software delivery?
How do we create predictability in our software delivery?
What’s required for you to feel inspired by your work?

Hosting

Which is your favourite cloud provider and why?
What does cloud native mean to you?
What is your relationship with Kubernetes?
What is your thoughts on serverless?
How do you measure uptime of your services?
How do you collect telemetry from your services?
Mention a way to improve availability of your services
How do you monitor the services you have released?
What would make you choose on-prem hosting over cloud?
What is a good way of managing SSL certificates?
What aspects do we need to consider regarding data protection laws?

Agile Software Development

What is your opinion on Scrum?
What is your opinion on user stories?
What is the most common impediment for you to be able to do your job?
How do you estimate correctly?
Which meetings do you consider necessary?
How do we make sure to maximise customer value?
What roles do you have in your optimal development team?
What activities do you think a team should do to improve its delivery?
The team will not be able to deliver in time. What is your proposed solution?
What do you expect from a project manager?
What does it mean to have a good team culture?
How do you follow up on progress in a project?

Software Design

What is your opinion on Microservices?
What is your opinion on SOLID?
What is your view on ORM frameworks?
What does object oriented programming mean to you?
In what capacity do you use functional programming?
Where do you draw the line between refactoring and rewrite?
Where do you draw the line between buying software or building it yourself?
What is your perspective on “best practices”?
How do you document your software design?
What tools do you use to design your software?

Other

What technological advancement do you consider a fad, and expect to be gone in 5 years?
How do you think we’ll be writing software in the future?
What will be the major challenges for our industry moving forward?
What do you think will happen with Machine Learning and AI?
What technology would you like to specialise in?
What technologies would you like to learn to broaden your expertise?
If you were not a software developer, what would you be doing instead?
What is, your opinion, the worst mistake done in history of computing?
What do you think is the most important traits/qualities for a developer to have?
How do you contribute to a good team culture?
What is required for you to feel satisfied with your work?
What can we do to prioritise diversity and promote an inclusive environment?
How do you learn new skills?
What does ethical coding mean to you, and how do you write code responsibly?
Does a software developer have to know how a computer works?

Please don’t ask your candidate all 100 questions :) and make sure that you ask non development related questions as well. Happy hiring!