State of Wisconsin Software Engineer Interview Guide

The 60-second brief

A Software Engineer at the State of Wisconsin plays a critical role in designing, developing, and maintaining software solutions that enhance governmental operations and public services. This position is vital in ensuring that state systems are efficient, secure, and user-friendly, ultimately impacting the lives of Wisconsin citizens. As a Software Engineer, you will be working on projects that streamline processes, improve accessibility to services, and support data-driven decision-making within various state departments. Your contributions will directly influence a range of applications, from public health systems to transportation management tools. The work is both challenging and rewarding, involving complex problem-solving and innovative thinking to tackle issues that affect a large population.

This guide is scoped to a Software Engineer candidate at State of Wisconsin.

Focus areas

• SQL (Querying)
• Software Engineering (Core Role Skills)
• SQL Fundamentals (Data Access Skills)

The State of Wisconsin interview process

State of Wisconsin candidates report 5 rounds over 4-6 weeks. The stages below are what candidates describe, not a published process.

Application Submission

Candidates submit their applications online for the Software Engineer position.

What to demonstrate

• Candidates submit their applications online for the Software Engineer position
• Depth in SQL (Querying)

How to prepare

• Answer aloud and timed: Explain the difference between a primary key and a foreign key in SQL.
• Answer aloud and timed: What are the principles of Object-Oriented Programming (OOP)?

Initial Interview Contact

Candidates are contacted for an interview after their application is reviewed.

What to demonstrate

• Candidates are contacted for an interview after their application is reviewed
• Depth in SQL (Querying)

How to prepare

• Answer aloud and timed: Describe how you would optimize a slow-running query.
• Answer aloud and timed: What are common security practices for web applications?

Technical Written Test

Candidates complete a technical written test focusing on SQL and basic programming concepts.

What to demonstrate

• Candidates complete a technical written test focusing on SQL and basic programming concepts
• Depth in SQL (Querying)

How to prepare

• Answer aloud and timed: How do you handle version control in collaborative projects?
• Answer aloud and timed: Describe a time when you faced a significant challenge in a project. How did you overcome it?

Oral Examination

Candidates participate in an oral examination that incorporates behavioral questions.

What to demonstrate

• Candidates participate in an oral examination that incorporates behavioral questions
• Depth in SQL (Querying)

How to prepare

• Answer aloud and timed: How do you prioritize tasks when managing multiple projects?
• Answer aloud and timed: Give an example of how you worked effectively in a team.

Final Evaluation

Interviewers assess candidates on technical expertise and cultural fit within the team.

What to demonstrate

• Interviewers assess candidates on technical expertise and cultural fit within the team
• Depth in SQL (Querying)

How to prepare

• Answer aloud and timed: How do you handle feedback and criticism?
• Answer aloud and timed: Explain a situation where you had to persuade a team member to adopt your approach.

Where candidates lose points

Prepare Thoroughly

Familiarize yourself with common technical and behavioral interview questions to build confidence.

Practice Coding

Regularly solve coding problems to sharpen your skills and improve your problem-solving speed.

Showcase Your Work

Be ready to discuss past projects and contributions, highlighting your role and the impact of your work.

Understand State Values

Research the mission and values of the State of Wisconsin to align your answers with their objectives.

Questions & practice

Write a function that reverses a string.

Medium · Coding / Algorithms

Approach

1. Restate the input: its shape, its size, and what is guaranteed about it.
2. Name the brute-force solution and its complexity before improving on it.
3. Choose the data structure from the access pattern, not from familiarity.
4. State the target complexity and say which constraint rules the naive version out.

Follow-up

• How does this change if the input no longer fits in memory?
• What is the worst case, and how likely is it on real data?

How would you implement a search algorithm for a sorted array?

Medium · Coding / Algorithms

Approach

1. Restate the input: its shape, its size, and what is guaranteed about it.
2. Name the brute-force solution and its complexity before improving on it.
3. Choose the data structure from the access pattern, not from familiarity.
4. State the target complexity and say which constraint rules the naive version out.

Follow-up

• How does this change if the input no longer fits in memory?
• What is the worst case, and how likely is it on real data?

Describe the time complexity of a binary search.

Medium · Coding / Algorithms

Approach

1. Restate the input: its shape, its size, and what is guaranteed about it.
2. Name the brute-force solution and its complexity before improving on it.
3. Choose the data structure from the access pattern, not from familiarity.
4. State the target complexity and say which constraint rules the naive version out.

Follow-up

• How does this change if the input no longer fits in memory?
• What is the worst case, and how likely is it on real data?

Write a function to check if a linked list is a palindrome.

Medium · Coding / Algorithms

Approach

1. Restate the input: its shape, its size, and what is guaranteed about it.
2. Name the brute-force solution and its complexity before improving on it.
3. Choose the data structure from the access pattern, not from familiarity.
4. State the target complexity and say which constraint rules the naive version out.

Follow-up

• How does this change if the input no longer fits in memory?
• What is the worst case, and how likely is it on real data?

Explain how you would approach solving a problem using recursion.

Medium · Coding / Algorithms

Approach

1. Restate the input: its shape, its size, and what is guaranteed about it.
2. Name the brute-force solution and its complexity before improving on it.
3. Choose the data structure from the access pattern, not from familiarity.
4. State the target complexity and say which constraint rules the naive version out.

Follow-up

• How does this change if the input no longer fits in memory?
• What is the worst case, and how likely is it on real data?

Explain the difference between a primary key and a foreign key in SQL.

Medium · Technical / Domain Questions

Approach

1. Name the grain you start from and join outward from it.
2. Check whether any join is one-to-many before aggregating, or the sums inflate.
3. Say which index the query would use, and what makes it unusable.
4. Handle the rows that do not match: that is usually the actual question.

Follow-up

• How does the query change if that join becomes one-to-many?
• What happens to this when the table is ten times larger?

Describe how you would optimize a slow-running query.

Medium · Technical / Domain Questions

Approach

1. Name the grain you start from and join outward from it.
2. Check whether any join is one-to-many before aggregating, or the sums inflate.
3. Say which index the query would use, and what makes it unusable.
4. Handle the rows that do not match: that is usually the actual question.

Follow-up

• How does the query change if that join becomes one-to-many?
• What happens to this when the table is ten times larger?

What are the principles of Object-Oriented Programming (OOP)?

Medium · Technical / Domain Questions

Approach

1. Clarify what is being asked and what a complete answer contains.
2. State your assumptions explicitly before working the problem.
3. Say what you would check first and why it is the highest-information step.
4. Work from the requirement backwards to the design.

Follow-up

• What assumption would you test first?
• How would you know your answer was wrong?

What are common security practices for web applications?

Medium · Technical / Domain Questions

Approach

1. Clarify what is being asked and what a complete answer contains.
2. State your assumptions explicitly before working the problem.
3. Say what you would check first and why it is the highest-information step.
4. Work from the requirement backwards to the design.

Follow-up

• What assumption would you test first?
• How would you know your answer was wrong?

If given a project with vague requirements, how would you proceed?

Medium · Problem-Solving / Case Studies

Approach

1. Clarify what is being asked and what a complete answer contains.
2. State your assumptions explicitly before working the problem.
3. Say what you would check first and why it is the highest-information step.
4. Work from the requirement backwards to the design.

Follow-up

• What assumption would you test first?
• How would you know your answer was wrong?

Describe how you would approach designing a new feature for an existing application.

Medium · Problem-Solving / Case Studies

Approach

1. Clarify what is being asked and what a complete answer contains.
2. State your assumptions explicitly before working the problem.
3. Say what you would check first and why it is the highest-information step.
4. Work from the requirement backwards to the design.

Follow-up

• What assumption would you test first?
• How would you know your answer was wrong?

What steps would you take to ensure the software you develop is user-friendly?

Medium · Problem-Solving / Case Studies

Approach

1. Clarify what is being asked and what a complete answer contains.
2. State your assumptions explicitly before working the problem.
3. Say what you would check first and why it is the highest-information step.
4. Work from the requirement backwards to the design.

Follow-up

• What assumption would you test first?
• How would you know your answer was wrong?

How would you balance technical debt against project deadlines?

Medium · Problem-Solving / Case Studies

Approach

1. Clarify what is being asked and what a complete answer contains.
2. State your assumptions explicitly before working the problem.
3. Say what you would check first and why it is the highest-information step.
4. Work from the requirement backwards to the design.

Follow-up

• What assumption would you test first?
• How would you know your answer was wrong?

Walk me through your process for debugging a complex software issue.

Medium · Problem-Solving / Case Studies

Approach

1. Establish what changed and when, before forming any theory.
2. Pick a bisection that eliminates candidates whichever way it turns out.
3. Check the instrumentation before believing the symptom.
4. Separate the trigger from the cause; the deploy is rarely the bug.

Follow-up

• What would you look at first, and what would it rule out?
• How would you tell a cause from a coincidence here?

Suggested practice checklist

Built from the rounds and topics State of Wisconsin candidates report.

Day 1 — Map the State of Wisconsin loop

• Write out the reported sequence: Application Submission, Initial Interview Contact, Technical Written Test, Oral Examination, Final Evaluation.
• For each round, write one sentence on what it is judging, from the description above, and mark the one you are least ready for.

Deliverable: A one-page map of the 5 reported rounds, with the weakest marked.

Day 2 — Work SQL (Querying)

• Spend the session on SQL (Querying), which State of Wisconsin candidates report being tested on.
• Write one worked example in SQL (Querying) and time yourself on it.

Deliverable: One timed worked example in SQL (Querying).

Day 3 — Work Software Engineering (Core Role Skills)

• Spend the session on Software Engineering (Core Role Skills), which State of Wisconsin candidates report being tested on.
• Write one worked example in Software Engineering (Core Role Skills) and time yourself on it.

Deliverable: One timed worked example in Software Engineering (Core Role Skills).

Day 4 — Work SQL Fundamentals (Data Access Skills)

• Spend the session on SQL Fundamentals (Data Access Skills), which State of Wisconsin candidates report being tested on.
• Write one worked example in SQL Fundamentals (Data Access Skills) and time yourself on it.

Deliverable: One timed worked example in SQL Fundamentals (Data Access Skills).

Day 5 — Answer out loud: Technical / Domain Questions

• Answer aloud, timed: Explain the difference between a primary key and a foreign key in SQL.
• Answer aloud, timed: What are the principles of Object-Oriented Programming (OOP)?

Deliverable: Spoken answers to 2 reported Technical / Domain Questions question(s), under time.

Day 6 — Answer out loud: Behavioral / Leadership

• Answer aloud, timed: Describe a time when you faced a significant challenge in a project. How did you overcome it?
• Answer aloud, timed: How do you prioritize tasks when managing multiple projects?

Deliverable: Spoken answers to 2 reported Behavioral / Leadership question(s), under time.

Day 7 — Answer out loud: Problem-Solving / Case Studies

• Answer aloud, timed: Walk me through your process for debugging a complex software issue.
• Answer aloud, timed: If given a project with vague requirements, how would you proceed?

Deliverable: Spoken answers to 2 reported Problem-Solving / Case Studies question(s), under time.

Behavioural preparation

Behavioural rounds judge the decision you made and what it cost.

How do you handle version control in collaborative projects?

Medium · Technical / Domain Questions

Approach

1. Pick a story where you made the decision, not one where you watched it.
2. State the situation in two sentences and spend the rest on the reasoning.
3. Give the blast radius: what could have broken, and what you measured.
4. Name the disagreement and how you resolved it with evidence.

Follow-up

• What would you do differently if you ran that again?
• How did you know your change caused the improvement?

Describe a time when you faced a significant challenge in a project. How did you overcome it?

Medium · Behavioral / Leadership

Approach

1. Pick a story where you made the decision, not one where you watched it.
2. State the situation in two sentences and spend the rest on the reasoning.
3. Give the blast radius: what could have broken, and what you measured.
4. Name the disagreement and how you resolved it with evidence.

Follow-up

• What would you do differently if you ran that again?
• How did you know your change caused the improvement?

How do you prioritize tasks when managing multiple projects?

Medium · Behavioral / Leadership

Approach

1. Pick a story where you made the decision, not one where you watched it.
2. State the situation in two sentences and spend the rest on the reasoning.
3. Give the blast radius: what could have broken, and what you measured.
4. Name the disagreement and how you resolved it with evidence.

Follow-up

• What would you do differently if you ran that again?
• How did you know your change caused the improvement?

Give an example of how you worked effectively in a team.

Medium · Behavioral / Leadership

Approach

1. Pick a story where you made the decision, not one where you watched it.
2. State the situation in two sentences and spend the rest on the reasoning.
3. Give the blast radius: what could have broken, and what you measured.
4. Name the disagreement and how you resolved it with evidence.

Follow-up

• What would you do differently if you ran that again?
• How did you know your change caused the improvement?

How do you handle feedback and criticism?

Medium · Behavioral / Leadership

Approach

1. Pick a story where you made the decision, not one where you watched it.
2. State the situation in two sentences and spend the rest on the reasoning.
3. Give the blast radius: what could have broken, and what you measured.
4. Name the disagreement and how you resolved it with evidence.

Follow-up

• What would you do differently if you ran that again?
• How did you know your change caused the improvement?

Explain a situation where you had to persuade a team member to adopt your approach.

Medium · Behavioral / Leadership

Approach

1. Pick a story where you made the decision, not one where you watched it.
2. State the situation in two sentences and spend the rest on the reasoning.
3. Give the blast radius: what could have broken, and what you measured.
4. Name the disagreement and how you resolved it with evidence.

Follow-up

• What would you do differently if you ran that again?
• How did you know your change caused the improvement?