Swiss Re Software Engineer Interview Guide

The 60-second brief

As a Software Engineer at Swiss Re, you occupy a pivotal role in bridging the gap between complex insurance logic and scalable, high-performance technology. You are not merely writing code; you are building the digital infrastructure that enables Swiss Re to assess risk, manage global portfolios, and provide financial security to clients worldwide. Your work directly influences the stability and efficiency of products that operate at a massive scale. The role involves navigating a sophisticated ecosystem where traditional insurance expertise meets modern cloud-native development. You will collaborate with cross-functional teams, including product managers and domain experts, to deliver robust solutions using technologies like Java, Spring Boot, Angular, and cloud platforms.

This guide is scoped to a Software Engineer candidate at Swiss Re.

Focus areas

• System/load balancer implementation
• Spring Boot
• Interview coding exercises / algorithmic problem solving

The Swiss Re interview process

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

Initial Screening

May involve recorded video responses or automated coding tests to assess baseline technical proficiency.

What to demonstrate

• May involve recorded video responses or automated coding tests to assess baseline technical proficiency
• Depth in System/load balancer implementation

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.

In-Depth Technical Interviews

Focus on deep-dive technical discussions and architectural problem-solving.

What to demonstrate

• Focus on deep-dive technical discussions and architectural problem-solving
• Depth in System/load balancer implementation

How to prepare

• Answer aloud and timed: What are the primary differences between threads and processes?
• Answer aloud and timed: Describe the core principles of SOLID, DRY, and YAGNI in the context of building a load balancer.

Cultural Fit Evaluation

Assess alignment with company culture and values through discussions.

What to demonstrate

• Assess alignment with company culture and values through discussions
• Depth in System/load balancer implementation

How to prepare

• Answer aloud and timed: How do you implement dependency injection and why is it critical for testing?
• Answer aloud and timed: Describe your approach to designing a cloud-native application.

Where candidates lose points

Structure your coding

Even in automated assessments, prioritize code quality, variable naming, and modularity over quick-and-dirty solutions.

Prepare your stories

Use the STAR method (Situation, Task, Action, Result) for behavioral questions. This keeps your answers focused and impactful.

Clarify the role

Since Swiss Re advertises for various subsidiaries, confirm early on which specific team or project you are interviewing for to ensure your technical prep is aligned.

Be ready for SQL

Don't neglect your database knowledge; questions about joins, unions, and basic query optimization appear frequently.

Questions & practice

How do you handle multithreading and concurrency in high-load applications?

Medium · Technical & Domain Proficiency

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?

What are the primary differences between threads and processes?

Medium · Technical & Domain Proficiency

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?

Archive a resource graph without breaking live references or recursing

Medium · graph traversal · topological order · tenant isolation

Resources reference other resources within a tenant; for the largest tenant the reference table holds up to 2,000,000 nodes and 8,000,000 edges. Archiving a resource must archive everything reachable from it that nothing outside the set still references, refuse when a live external referrer exists, and terminate when references form cycles, which they legitimately do. Produce the archive order and the refusal list, targeting O(V+E). Say what stops the traversal crossing a tenant boundary, and why recursion is the wrong control structure at this size.

Approach

1. Load the subgraph with the tenant predicate on both endpoints of the edge, not only on the side you started from. Scoping the left table alone is the classic cross-tenant leak: one mis-entered edge then pulls another tenant's resources into the traversal and, worse, into the archive.
2. Traverse iteratively with an explicit stack. A 2,000,000-node graph can hold a chain deep enough to exhaust a native stack in the low tens of thousands of frames, and that failure is a process crash rather than an error you can return.
3. Treat cycles as data rather than corruption: compute strongly connected components with Tarjan in O(V+E) using its own explicit stack, then condense. The condensation is a DAG, so a topological order over it gives the archive order, and every member of a component archives in one transaction because no order within a cycle is valid.
4. Decide refusals with reverse edges. A candidate is archivable only if every in-edge originates inside the candidate set, so build the transpose or count in-degrees restricted to the visited set, and emit each blocked resource with the id of the external referrer, which is the only part of the answer an operator can act on.

Follow-up

• The graph is read in one query and the archive writes a minute later. What can change in between, and how do you make the write safe?
• The candidate set is 400,000 resources. Is that one transaction, and if not, what does a half-finished archive look like to a reader?

Why are you looking to leave your current role and join Swiss Re?

Medium · Behavioral & Cultural Alignment

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?

Replace offset paging on the resource feed with keyset

Easy · keyset pagination · composite index · sort order

resource holds resource_id, tenant_id, owner_user_id, title, body_ref, version, status ('draft','active','archived','deleted'), created_at, updated_at, deleted_at, with an index on (tenant_id, status, updated_at DESC, resource_id DESC). The listing endpoint returns active resources for one tenant, newest update first, 50 per page, today with LIMIT 50 OFFSET n. Tenants reach page 400 and rows are created while they read. Write the keyset query, define what the cursor carries and how it is encoded, and say which part of the index each predicate uses. Assume PostgreSQL 16.

Approach

1. Name the two failures separately. OFFSET 20000 makes the server produce and discard 20,000 rows, so page cost grows with depth rather than with page size. Independently, any write that changes how many rows sort above the offset moves the window between two fetches, and the direction decides which anomaly you get: an insert lands at the head of updated_at DESC and pushes already-returned rows down past the boundary, so they are returned a second time; a delete above the offset, or a row whose updated_at is bumped above the cursor, pulls rows up and one is never returned at all. Nothing in the response reveals either.
2. Write the seek: WHERE tenant_id = $1 AND status = 'active' AND (updated_at, resource_id) < ($2, $3) ORDER BY updated_at DESC, resource_id DESC LIMIT 50. The row-value comparison is one index range rather than a disjunction, and both columns are NOT NULL, which is what makes that comparison well defined.
3. Map each predicate onto the index: tenant_id and status are equality on the leading columns, (updated_at, resource_id) is the range, and the ORDER BY matches the index order so no Sort node appears and the scan stops after 50 rows. The DESC in the definition only matters for mixed directions — a plain ascending btree on the same columns is read backwards for this query.
4. Put both sort columns in the cursor and nothing the client can tamper with into another tenant: base64 of (updated_at, resource_id), validated server-side, with tenant_id taken from the principal.

Follow-up

• The client asks for 'jump to page 400'. What do you offer instead, and what does the honest version cost?
• Sort order becomes user-selectable across four columns. How many indexes is that, and which would you refuse to add?

Explain the difference between constant and read-only variables in your primary language.

Medium · Technical & Domain Proficiency

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 the core principles of SOLID, DRY, and YAGNI in the context of building a load balancer.

Medium · Technical & Domain Proficiency

Approach

1. Fix the scope first: who calls this, how often, and what they do when it fails.
2. Name the read and write paths separately; they rarely have the same bottleneck.
3. Choose a partition key and say what query it makes expensive.
4. State the consistency you need, and where you are willing to be stale.

Follow-up

• What breaks first when traffic grows ten times?
• How does this behave when that dependency is down for an hour?

How do you implement dependency injection and why is it critical for testing?

Medium · Technical & Domain Proficiency

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 your approach to designing a cloud-native application.

Medium · System Design & Architecture

Approach

1. Fix the scope first: who calls this, how often, and what they do when it fails.
2. Name the read and write paths separately; they rarely have the same bottleneck.
3. Choose a partition key and say what query it makes expensive.
4. State the consistency you need, and where you are willing to be stale.

Follow-up

• What breaks first when traffic grows ten times?
• How does this behave when that dependency is down for an hour?

How would you design a load balancer from scratch?

Medium · System Design & Architecture

Approach

1. Fix the scope first: who calls this, how often, and what they do when it fails.
2. Name the read and write paths separately; they rarely have the same bottleneck.
3. Choose a partition key and say what query it makes expensive.
4. State the consistency you need, and where you are willing to be stale.

Follow-up

• What breaks first when traffic grows ten times?
• How does this behave when that dependency is down for an hour?

Explain the role of RESTful APIs and how you manage HTTP headers and status codes.

Medium · System Design & Architecture

Approach

1. Fix the scope first: who calls this, how often, and what they do when it fails.
2. Name the read and write paths separately; they rarely have the same bottleneck.
3. Choose a partition key and say what query it makes expensive.
4. State the consistency you need, and where you are willing to be stale.

Follow-up

• What breaks first when traffic grows ten times?
• How does this behave when that dependency is down for an hour?

What design patterns do you favor for building modular, decoupled systems?

Medium · System Design & Architecture

Approach

1. Fix the scope first: who calls this, how often, and what they do when it fails.
2. Name the read and write paths separately; they rarely have the same bottleneck.
3. Choose a partition key and say what query it makes expensive.
4. State the consistency you need, and where you are willing to be stale.

Follow-up

• What breaks first when traffic grows ten times?
• How does this behave when that dependency is down for an hour?

How do you manage data consistency in distributed systems?

Medium · System Design & Architecture

Approach

1. Fix the scope first: who calls this, how often, and what they do when it fails.
2. Name the read and write paths separately; they rarely have the same bottleneck.
3. Choose a partition key and say what query it makes expensive.
4. State the consistency you need, and where you are willing to be stale.

Follow-up

• What breaks first when traffic grows ten times?
• How does this behave when that dependency is down for an hour?

One log partition stops advancing while the others drain

Easy · poison message · head-of-line blocking · consumer lag

Search results for a subset of tenants are hours stale; the rest are current. The projection consumer reports lag of zero on 15 of 16 partitions and 400,000 on one. Its error rate is flat and its CPU is idle. outbox_event has no pending rows older than a second, so the relay has published everything it holds. Identify the mechanism, give the ordered checks, and state what you do in the first ten minutes versus what you change permanently.

Approach

1. Read the lag distribution first. A slow consumer lags everywhere; zero on fifteen partitions and 400,000 on one is not throughput. Idle CPU on the stuck partition means the consumer is not advancing its offset at all, which points at one message it cannot get past rather than at a rate problem.
2. Exonerate the producer before touching the consumer. No pending outbox rows older than a second means the relay published, so the event exists in the log. This separates never sent from sent and never applied, which are different code paths and usually different owners.
3. Read the message at the stuck offset and the handler's log lines for its event_id. A flat error rate with no progress has two explanations and you must distinguish them: the handler is throwing and the retry loop is swallowing it, or the handler is blocking on something and never returning. Idle CPU with no error lines favours the second.
4. Mitigate before diagnosing further. Move the offending event to a dead-letter store and commit the offset past it. Adding consumers does nothing here, because a partition is consumed by exactly one member of the group, and the blast radius is every aggregate hashed to that partition, not only the aggregate that produced the bad event.

Follow-up

• The dead-lettered event carried aggregate_version 7 and the projection had applied 6. What must the replay do differently if 8 and 9 landed in the meantime?
• How do you show staleness to the user while the partition is behind, given the API already returns the projection's watermark?

Suggested practice checklist

Built from the rounds and topics Swiss Re candidates report.

Day 1 — Map the Swiss Re loop

• Write out the reported sequence: Initial Screening, In-Depth Technical Interviews, Cultural Fit 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 3 reported rounds, with the weakest marked.

Day 2 — Work System/load balancer implementation

• Spend the session on System/load balancer implementation, which Swiss Re candidates report being tested on.
• Write one worked example in System/load balancer implementation and time yourself on it.

Deliverable: One timed worked example in System/load balancer implementation.

Day 3 — Work Spring Boot

• Spend the session on Spring Boot, which Swiss Re candidates report being tested on.
• Write one worked example in Spring Boot and time yourself on it.

Deliverable: One timed worked example in Spring Boot.

Day 4 — Work Interview coding exercises / algorithmic problem solving

• Spend the session on Interview coding exercises / algorithmic problem solving, which Swiss Re candidates report being tested on.
• Write one worked example in Interview coding exercises / algorithmic problem solving and time yourself on it.

Deliverable: One timed worked example in Interview coding exercises / algorithmic problem solving.

Day 5 — Answer out loud: Technical & Domain Proficiency

• Answer aloud, timed: Explain the difference between constant and read-only variables in your primary language.
• Answer aloud, timed: How do you handle multithreading and concurrency in high-load applications?

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

Day 6 — Answer out loud: System Design & Architecture

• Answer aloud, timed: Describe your approach to designing a cloud-native application.
• Answer aloud, timed: How would you design a load balancer from scratch?

Deliverable: Spoken answers to 2 reported System Design & Architecture question(s), under time.

Day 7 — Answer out loud: Behavioral & Cultural Alignment

• Answer aloud, timed: Why are you looking to leave your current role and join Swiss Re?
• Answer aloud, timed: Describe a time you had to take direction from a superior with whom you disagreed.

Deliverable: Spoken answers to 2 reported Behavioral & Cultural Alignment question(s), under time.

Behavioural preparation

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

Describe a time you had to take direction from a superior with whom you disagreed.

Medium · Behavioral & Cultural Alignment

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 manage your time and prioritize tasks when deadlines are tight?

Medium · Behavioral & Cultural Alignment

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?

Tell us about a time you demonstrated leadership or initiative in a project.

Medium · Behavioral & Cultural Alignment

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 from peers during code reviews?

Medium · Behavioral & Cultural Alignment

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?