Fictiv Software Engineer Interview Guide

The 60-second brief

As a Software Engineer at Fictiv, you are at the intersection of digital transformation and physical manufacturing. You will be building the core infrastructure that powers a global, on-demand manufacturing platform, connecting engineers and product designers with high-quality, reliable manufacturing capacity. Your work directly impacts how physical goods—from prototypes to production-grade parts—are brought to life, making your software the backbone of a complex, logistics-heavy supply chain. This role is critical because it demands both technical rigor and an ability to navigate the ambiguity of a fast-paced, scaling company. You will likely contribute to full-stack development, optimizing backend systems for complex manufacturing workflows or enhancing frontend interfaces to improve the user experience for our manufacturing partners.

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

Focus areas

• Data Structures & Algorithms (DSA)
• Debugging (code-level)
• Coding (hands-on / live coding)

The Fictiv interview process

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

Initial Screening

The first step involves a preliminary assessment to gauge candidate fit and qualifications.

What to demonstrate

• The first step involves a preliminary assessment to gauge candidate fit and qualifications
• Depth in Data Structures & Algorithms (DSA)

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 Deep-Dive

Candidates engage in coding and system design assessments to evaluate technical skills.

What to demonstrate

• Candidates engage in coding and system design assessments to evaluate technical skills
• Depth in Data Structures & Algorithms (DSA)

How to prepare

• Answer aloud and timed: Solve a classic LeetCode-style problem involving arrays or string manipulation.
• Answer aloud and timed: Describe how you handle memory management in your preferred language.

Values and Team Fit

A conversation focused on cultural alignment and how the candidate's values align with the team.

What to demonstrate

• A conversation focused on cultural alignment and how the candidate's values align with the team
• Depth in Data Structures & Algorithms (DSA)

How to prepare

• Prepare three examples from your own work, each with a decision you made and an outcome you can quantify.
• Re-read the description of the values and team fit above and write down what you would ask to confirm before it.

Where candidates lose points

Do your research

Understand what Fictiv does. Being able to explain how your code helps a customer get a part manufactured faster will set you apart from other candidates.

Practice your "Why

Be prepared to explain your career choices and why you are interested in the manufacturing space.

Ask great questions

Use the time at the end of the interview to ask about the team's biggest technical challenges or how they balance quality with speed.

Be proactive

If you experience technical issues (like a bad connection), communicate clearly and ask for an alternative, as shown in successful candidate experiences.

Questions & practice

Explain the difference between process and threads.

Medium · Technical & Coding 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?

Solve a classic LeetCode-style problem involving arrays or string manipulation.

Medium · Technical & Coding Fundamentals

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 handle memory management in your preferred language.

Medium · Technical & Coding 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 would you optimize a slow-running SQL query?

Medium · Technical & Coding 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?

Explain why the owner filter ignores the listing index

Medium · composite index · query plans · sort elimination

The only index on resource is (tenant_id, status, updated_at DESC, resource_id DESC). A new endpoint returns one user's resources across all statuses, newest created first: WHERE tenant_id = $1 AND owner_user_id = $2 ORDER BY created_at DESC LIMIT 20. On a tenant with 2M rows it takes 900 ms and EXPLAIN shows a sort above a large scan. Explain precisely why the existing index cannot serve it, give the index that can, and state which of these the new index still will not help: owner_user_id alone across tenants; the same query ordered by updated_at. PostgreSQL 16.

Approach

1. Separate the two jobs an index does. For filtering, a composite btree is seekable only on a left prefix, so with no predicate on status the scan can at best range over tenant_id and test owner_user_id per row; PostgreSQL 16 has no btree skip scan to jump the unconstrained column.
2. For ordering, the index is sorted by (status, updated_at) within a tenant and not by created_at, so the LIMIT cannot stop early: every matching row is read and then sorted. That is the 'Sort Method: top-N heapsort' line, and it is why the plan reads 2M rows to answer with 20.
3. Derive the replacement from the access path — equality, equality, then the ordering column: CREATE INDEX CONCURRENTLY ON resource (tenant_id, owner_user_id, created_at DESC). The scan seeks to the (tenant, owner) range and walks 20 entries in order, so the Sort node disappears along with the row-read.
4. Treat INCLUDE (title, status) as conditional, not free. An index-only scan still visits the heap for any row whose page is not marked all-visible, so on a table taking 1.2k writes/second the win depends on autovacuum keeping the visibility map current, and the wider index costs more on every insert.

Follow-up

• 90% of rows are status='active'. Would a partial index WHERE status = 'active' change your answer, and for which of the three queries?
• A dashboard runs this for 40 owners in one page load. What changes about the design?

Explain the principles of RESTful API design.

Medium · Technical & Coding Fundamentals

Approach

1. Say who the caller is and what they do when the call fails halfway.
2. Define the identity of a request so a retry cannot double-apply it.
3. Separate accepted, pending, failed and confirmed; they are different facts.
4. Design the error taxonomy before the success shape; callers branch on it.

Follow-up

• What happens if the caller retries after a timeout?
• How does a client discover it is on an old version of this contract?

Design a URL shortening service or a simplified version of a file-upload system.

Medium · System Design & Debugging

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 system that handles asynchronous task processing?

Medium · System Design & Debugging

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 ensure data consistency in a distributed system?

Medium · System Design & Debugging

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?

Walk me through how you would debug a production service that is experiencing high latency.

Medium · System Design & Debugging

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?

Given a broken piece of code, identify the bug and suggest a fix.

Medium · System Design & Debugging

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 Fictiv candidates report.

Day 1 — Map the Fictiv loop

• Write out the reported sequence: Initial Screening, Technical Deep-Dive, Values and Team Fit.
• 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 Data Structures & Algorithms (DSA)

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

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

Day 3 — Work Debugging (code-level)

• Spend the session on Debugging (code-level), which Fictiv candidates report being tested on.
• Write one worked example in Debugging (code-level) and time yourself on it.

Deliverable: One timed worked example in Debugging (code-level).

Day 4 — Work Coding (hands-on / live coding)

• Spend the session on Coding (hands-on / live coding), which Fictiv candidates report being tested on.
• Write one worked example in Coding (hands-on / live coding) and time yourself on it.

Deliverable: One timed worked example in Coding (hands-on / live coding).

Day 5 — Answer out loud: Technical & Coding Fundamentals

• Answer aloud, timed: Explain the difference between process and threads.
• Answer aloud, timed: How would you optimize a slow-running SQL query?

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

Day 6 — Answer out loud: System Design & Debugging

• Answer aloud, timed: Design a URL shortening service or a simplified version of a file-upload system.
• Answer aloud, timed: Walk me through how you would debug a production service that is experiencing high latency.

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

Day 7 — Answer out loud: Behavioral & Values

• Answer aloud, timed: Tell me about a time you had a technical disagreement with a teammate; how was it resolved?
• Answer aloud, timed: Why do you want to work at Fictiv specifically?

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

Behavioural preparation

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

Tell me about a time you had a technical disagreement with a teammate; how was it resolved?

Medium · Behavioral & Values

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?

Why do you want to work at Fictiv specifically?

Medium · Behavioral & Values

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 challenging project where you had to learn a new technology on the fly.

Medium · Behavioral & Values

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 non-technical stakeholders?

Medium · Behavioral & Values

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 me about a time you missed a deadline or failed to deliver; what did you learn?

Medium · Behavioral & Values

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?