Chubb Software Engineer Interview Guide

The 60-second brief

A Software Engineer at Chubb plays a pivotal role in maintaining the technical backbone of one of the world’s largest publicly traded property and casualty insurance companies. You are not just writing code; you are building scalable, secure, and high-performance applications that enable the global insurance business to operate efficiently, process complex risk data, and provide seamless service to policyholders. The work environment at Chubb is characterized by a balance between legacy system modernization and the adoption of modern cloud-native technologies. You will likely contribute to critical internal tools, customer-facing platforms, or data-driven applications that require a deep understanding of both business logic and robust software architecture.

This guide is scoped to a Software Engineer candidate at Chubb.

Focus areas

• DSA (Data Structures & Algorithms)
• Algorithms (problem solving)
• OOP / OOPs Concepts

The Chubb interview process

Chubb candidates report 3 rounds over 3-5 weeks. The stages below are what candidates describe, not a published process.

Recruiter Screen

Initial screening call with a recruiter to assess candidate fit.

What to demonstrate

• Initial screening call with a recruiter to assess candidate fit
• Depth in DSA (Data Structures & Algorithms)

How to prepare

• Be able to walk your CV end to end in two minutes, and say why this company specifically.
• Have your salary expectations, notice period and location constraints ready, and ask for the rest of the loop in writing.

Technical Assessments

Candidates undergo technical assessments to evaluate their expertise.

What to demonstrate

• Candidates undergo technical assessments to evaluate their expertise
• Depth in DSA (Data Structures & Algorithms)

How to prepare

• Answer aloud and timed: Can you explain the concept of Normalization in a database?
• Answer aloud and timed: What are the differences between Process and Thread in an operating system?

Discussions with Team Leads

Interviews with team leads or managers to discuss technical skills and cultural fit.

What to demonstrate

• Interviews with team leads or managers to discuss technical skills and cultural fit
• Depth in DSA (Data Structures & Algorithms)

How to prepare

• Answer aloud and timed: How does JVM memory management work in Java?
• Answer aloud and timed: Write a program to print characters that appear more than once in a string.

Where candidates lose points

Own your resume

Every line on your resume is fair game. If you list a technology, be prepared to answer deep questions about it.

Ask thoughtful questions

At the end of the interview, ask about the team’s current challenges or the company’s direction. This shows genuine interest.

Be ready for "Why Chubb?

Show that you understand the insurance industry and why you want to apply your engineering skills in this specific domain.

Maintain professionalism

Even if an interview feels "chill," remain professional and structured in your communication.

Questions & practice

What are the differences between Process and Thread in an operating system?

Medium · Core Computer Science Fundamentals

Approach

1. Say what the runtime actually does before reasoning about the code.
2. Name what is shared across threads and what owns each piece of state.
3. Identify the window where an invariant is briefly untrue.
4. Distinguish a value from a reference to it, and say which one you handed out.

Follow-up

• What happens if two callers reach this at the same time?
• Where could this allocate more than you expect?

How does JVM memory management work in Java?

Medium · Core Computer Science Fundamentals

Approach

1. Say what the runtime actually does before reasoning about the code.
2. Name what is shared across threads and what owns each piece of state.
3. Identify the window where an invariant is briefly untrue.
4. Distinguish a value from a reference to it, and say which one you handed out.

Follow-up

• What happens if two callers reach this at the same time?
• Where could this allocate more than you expect?

Write a program to print characters that appear more than once in a string.

Medium · Coding and Problem Solving

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 find the frequency of a letter in a string?

Medium · Coding and Problem Solving

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?

Can you implement a basic sorting algorithm or explain how it works?

Medium · Coding and Problem Solving

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 how you would approach a problem like sorting an array of 0s, 1s, and 2s.

Medium · Coding and Problem Solving

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?

Can you explain the concept of Normalization in a database?

Medium · Core Computer Science Fundamentals

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?

Write a simple SQL query involving JOINs and subqueries.

Medium · Coding and Problem Solving

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?

Explain the difference between Inheritance, Polymorphism, and Encapsulation.

Medium · Core Computer Science Fundamentals

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 is the difference between a Primary Key and a Foreign Key?

Medium · Core Computer Science Fundamentals

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?

Read latency spikes on a sixty-second sawtooth

Medium · cache stampede · single-flight · ttl

The cached listing read path serves about 14k reads/second at an 85% hit rate. p99 sits at 35 ms for 57 seconds, jumps to 900 ms for 3, and repeats. During each spike the primary shows several hundred identical listing queries starting within the same millisecond, all carrying one large tenant's id. Cache entries use a 60-second TTL. Give the mechanism, the ordered checks, the fix, and the correctness hazard your fix must not introduce.

Approach

1. Match the period to a configured number before theorising about load. A spike every 60 seconds against a 60-second TTL is an entry expiring, and you confirm it by correlating spike timestamps with the entry's write time rather than with the traffic curve. If the period had matched a cron or a GC interval instead, this is a different investigation.
2. Establish the concurrency of the miss. Several hundred identical queries in one millisecond means the miss path has no coalescing: every request that arrives between expiry and repopulation recomputes. The herd size is that key's arrival rate times its recompute time, so at 1.2k reads/second for the hot key and a 250 ms recompute you expect about 300 concurrent misses, which matches what is observed.
3. Add single-flight on the miss path so one caller per key recomputes under a short-lived lock while the rest wait for its result. Prefer stale-while-revalidate where the read tolerates it: return the expired value immediately and refresh asynchronously, which removes the latency spike rather than serialising it into a queue of waiters.
4. De-synchronise the keys. Write TTLs with jitter, for example 60 seconds plus or minus 10%, so a deploy or a mass invalidation does not align every key on the same second and turn a per-key herd into a fleet-wide one.

Follow-up

• The same sawtooth appears on a key that is invalidated on write rather than expired. Is that the same bug?
• How does your answer change if the recompute takes 4 seconds instead of 250 ms?

Suggested practice checklist

Built from the rounds and topics Chubb candidates report.

Day 1 — Map the Chubb loop

• Write out the reported sequence: Recruiter Screen, Technical Assessments, Discussions with Team Leads.
• 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 3 reported rounds, with the weakest marked.

Day 2 — Work DSA (Data Structures & Algorithms)

• Spend the session on DSA (Data Structures & Algorithms), which Chubb candidates report being tested on.
• Write one worked example in DSA (Data Structures & Algorithms) and time yourself on it.

Deliverable: One timed worked example in DSA (Data Structures & Algorithms).

Day 3 — Work Algorithms (problem solving)

• Spend the session on Algorithms (problem solving), which Chubb candidates report being tested on.
• Write one worked example in Algorithms (problem solving) and time yourself on it.

Deliverable: One timed worked example in Algorithms (problem solving).

Day 4 — Work OOP / OOPs Concepts

• Spend the session on OOP / OOPs Concepts, which Chubb candidates report being tested on.
• Write one worked example in OOP / OOPs Concepts and time yourself on it.

Deliverable: One timed worked example in OOP / OOPs Concepts.

Day 5 — Answer out loud: Core Computer Science Fundamentals

• Answer aloud, timed: Explain the difference between Inheritance, Polymorphism, and Encapsulation.
• Answer aloud, timed: What is the difference between a Primary Key and a Foreign Key?

Deliverable: Spoken answers to 2 reported Core Computer Science Fundamentals question(s), under time.

Day 6 — Answer out loud: Coding and Problem Solving

• Answer aloud, timed: Write a program to print characters that appear more than once in a string.
• Answer aloud, timed: How would you find the frequency of a letter in a string?

Deliverable: Spoken answers to 2 reported Coding and Problem Solving question(s), under time.

Day 7 — Answer out loud: Project-Based and Behavioral

• Answer aloud, timed: Tell me about a project on your resume that you are most proud of.
• Answer aloud, timed: How do you handle workplace conflicts within a technical team?

Deliverable: Spoken answers to 2 reported Project-Based and Behavioral question(s), under time.

Behavioural preparation

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

Tell me about a project on your resume that you are most proud of.

Medium · Project-Based and Behavioral

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 workplace conflicts within a technical team?

Medium · Project-Based and Behavioral

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 you had to learn a new technology quickly to solve a problem.

Medium · Project-Based and Behavioral

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?

What are your future career aspirations and how do they align with Chubb?

Medium · Project-Based and Behavioral

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?