At Product Madness, a Software Engineer plays a pivotal role in shaping the future of social mobile gaming. As one of the world's largest mobile game studios, the company focuses on delivering highly engaging, top-tier free-to-play social casino games to millions of active players globally. In this role, you are not just writing code; you are building the core mechanics, real-time multiplayer systems, and backend integrations that power massive, high-performance gaming ecosystems. Your work directly impacts user retention, game performance, and player satisfaction. You will tackle complex technical challenges, such as optimizing rendering pipelines, managing high-concurrency server environments, and ensuring seamless cross-platform functionality. Working closely with cross-functional teams of game artists, product managers, and UI/UX designers, you will translate creative visions into stable, scalable, and high-performing game features. This position is ideal for engineers who thrive in fast-paced, collaborative environments and are passionate about game development, systems architecture, and robust coding standards. Whether optimizing existing systems or architecting new gameplay features from scratch, your contributions will directly influence the entertainment experience of millions of players worldwide.
Conversational Screening Call
reportedInitial call to discuss the candidate's background and assess fit for the role.
What to demonstrate
- Initial call to discuss the candidate's background and assess fit for the role
- Depth in 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 Evaluations
reportedCandidates undergo practical coding assessments and architectural thinking evaluations.
What to demonstrate
- Candidates undergo practical coding assessments and architectural thinking evaluations
- Depth in Algorithms
How to prepare
- Answer aloud and timed: How does garbage collection work in C#, and what steps can you take in a game loop to minimize garbage collection spikes?
- Answer aloud and timed: Explain the concept of polymorphism and provide a concrete example of how it is used in game architecture.
Algorithmic Testing
reportedUtilization of online coding platforms for algorithmic challenges.
What to demonstrate
- Utilization of online coding platforms for algorithmic challenges
- Depth in Algorithms
How to prepare
- Answer aloud and timed: What are abstract classes and interfaces, and when would you choose one over the other in a game framework?
- Answer aloud and timed: Describe the Unity MonoBehaviour lifecycle, specifically highlighting the difference between Awake, Start, Update, and FixedUpdate.
Collaborative Coding Sessions
reportedLive coding sessions with senior engineering staff to evaluate coding skills.
What to demonstrate
- Live coding sessions with senior engineering staff to evaluate coding skills
- Depth in Algorithms
How to prepare
- Answer aloud and timed: How do you optimize draw calls and batching in Unity to ensure high performance on lower-end mobile devices?
- Answer aloud and timed: What are ScriptableObjects in Unity, and how would you use them to manage game data or configuration?
Deep Technical Discussions
reportedIn-depth discussions on technical topics relevant to the role.
What to demonstrate
- In-depth discussions on technical topics relevant to the role
- Depth in Algorithms
How to prepare
- Answer aloud and timed: Explain how you would handle asset loading and memory management using Addressables or AssetBundles.
- Answer aloud and timed: How do you handle physics calculations in Unity to prevent performance bottlenecks?
Behavioral Preparation
reportedPreparation for behavioral questions to assess cultural fit.
What to demonstrate
- Preparation for behavioral questions to assess cultural fit
- Depth in Algorithms
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 behavioral preparation above and write down what you would ask to confirm before it.
Final Decision
reportedThe final decision is communicated to the candidate, often within a week.
What to demonstrate
- The final decision is communicated to the candidate, often within a week
- Depth in Algorithms
How to prepare
- Answer aloud and timed: How would you design and implement an efficient pathfinding algorithm (such as A*) for a grid-based game board?
- Answer aloud and timed: What data structure would you use to implement a highly efficient leaderboard system, and what are its time complexities?
PracHub editorial advice for the preparation topics above.
Master the Unity Lifecycle
Be ready to explain the execution order of event functions in detail. Understand the performance implications of putting heavy calculations in Update or using GetComponent repeatedly.
Think About the Player
When designing systems or writing code, always consider the end-user experience. How does your code affect load times, battery consumption, and gameplay responsiveness?
Be Transparent About Your Work
In the technical talk and behavioral rounds, be prepared to discuss your past failures and what you learned from them. The team values self-awareness and a growth mindset.
Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.
Explain the four main pillars of Object-Oriented Programming and how you have applied them in your past projec
Explain the four main pillars of Object-Oriented Programming and how you have applied them in your past projects.
Approach
- Say what the runtime actually does before reasoning about the code.
- Name what is shared across threads and what owns each piece of state.
- Identify the window where an invariant is briefly untrue.
- 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 is the difference between a class and a struct in C#, and how do they impact memory allocation (stack vs.
What is the difference between a class and a struct in C#, and how do they impact memory allocation (stack vs. heap)?
Approach
- Say what the runtime actually does before reasoning about the code.
- Name what is shared across threads and what owns each piece of state.
- Identify the window where an invariant is briefly untrue.
- 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 garbage collection work in C#, and what steps can you take in a game loop to minimize garbage collect
How does garbage collection work in C#, and what steps can you take in a game loop to minimize garbage collection spikes?
Approach
- Say what the runtime actually does before reasoning about the code.
- Name what is shared across threads and what owns each piece of state.
- Identify the window where an invariant is briefly untrue.
- 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 abstract classes and interfaces, and when would you choose one over the other in a game framework?
What are abstract classes and interfaces, and when would you choose one over the other in a game framework?
Approach
- Say what the runtime actually does before reasoning about the code.
- Name what is shared across threads and what owns each piece of state.
- Identify the window where an invariant is briefly untrue.
- 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?
Explain how you would handle asset loading and memory management using Addressables or AssetBundles.
Explain how you would handle asset loading and memory management using Addressables or AssetBundles.
Approach
- Say what the runtime actually does before reasoning about the code.
- Name what is shared across threads and what owns each piece of state.
- Identify the window where an invariant is briefly untrue.
- 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?
Implement a function to detect a cycle in a linked list.
Implement a function to detect a cycle in a linked list.
Approach
- Restate the input: its shape, its size, and what is guaranteed about it.
- Name the brute-force solution and its complexity before improving on it.
- Choose the data structure from the access pattern, not from familiarity.
- 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?
Given an array of integers, find the contiguous subarray which has the largest sum (Kadane’s Algorithm).
Given an array of integers, find the contiguous subarray which has the largest sum (Kadane’s Algorithm).
Approach
- Restate the input: its shape, its size, and what is guaranteed about it.
- Name the brute-force solution and its complexity before improving on it.
- Choose the data structure from the access pattern, not from familiarity.
- 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?
What data structure would you use to implement a highly efficient leaderboard system, and what are its time co
What data structure would you use to implement a highly efficient leaderboard system, and what are its time complexities?
Approach
- Restate the input: its shape, its size, and what is guaranteed about it.
- Name the brute-force solution and its complexity before improving on it.
- Choose the data structure from the access pattern, not from familiarity.
- 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 program to reverse a string or manipulate an array in place without allocating extra memory.
Write a program to reverse a string or manipulate an array in place without allocating extra memory.
Approach
- Say what the runtime actually does before reasoning about the code.
- Name what is shared across threads and what owns each piece of state.
- Identify the window where an invariant is briefly untrue.
- 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?
Keep soft-deleted accounts from blocking re-registration
app_user holds user_id, tenant_id, email CITEXT, password_hash (NULL for SSO principals), email_verified_at, auth_version, status ('invited','active','suspended','deactivated'), created_at, updated_at, deleted_at. Two live accounts for one address inside a tenant must be impossible, but an address freed by a soft delete must be reusable, and the same tenant may delete and re-register it repeatedly. Write the uniqueness DDL for PostgreSQL 16, then the equivalent for MySQL 8 where partial indexes do not exist, and say what each permits once three deleted rows already hold that address.
Approach
- Start from what is actually unique: not (tenant_id, email), but (tenant_id, email) among live rows. PostgreSQL says that directly — CREATE UNIQUE INDEX app_user_live_email ON app_user (tenant_id, email) WHERE deleted_at IS NULL. A full constraint over the same two columns burns the address permanently the first time someone deletes an account.
- Keep case-insensitivity in the type or the index, never in the application: CITEXT as given, or UNIQUE (tenant_id, lower(email)) as an expression index where the extension is unavailable. A case-sensitive unique column is exactly how two accounts for one human appear.
- For MySQL 8 the predicate has to move inside the key: add a discriminator column that is a constant 0 while the row is live and is set to user_id on delete, with UNIQUE (tenant_id, email, deleted_marker). Live rows share the constant and still collide; deleted rows differ from each other and stop colliding.
- State the NULL variant and its dependency: leaving the marker NULL for deleted rows also works, because a unique index treats NULLs as distinct — true in MySQL, and true in PostgreSQL only under the default NULLS DISTINCT, which PostgreSQL 15 lets you reverse. Check the polarity against the three existing deleted rows: constant-on-live is what preserves the collision you want, and reversing it silently admits duplicate live accounts.
Follow-up
- A deleted account re-registers with the same address the next day. Do the old resource rows follow the new user_id, and how does the API keep the two principals apart?
- How do you honour an erasure request while resource_revision.actor_user_id still references this table?
Replace offset paging on the resource feed with keyset
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
- 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.
- 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.
- 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.
- 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 concept of polymorphism and provide a concrete example of how it is used in game architecture.
Explain the concept of polymorphism and provide a concrete example of how it is used in game architecture.
Approach
- Fix the scope first: who calls this, how often, and what they do when it fails.
- Name the read and write paths separately; they rarely have the same bottleneck.
- Choose a partition key and say what query it makes expensive.
- 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?
Describe the Unity MonoBehaviour lifecycle, specifically highlighting the difference between Awake, Start, Upd
Describe the Unity MonoBehaviour lifecycle, specifically highlighting the difference between Awake, Start, Update, and FixedUpdate.
Approach
- Clarify what is being asked and what a complete answer contains.
- State your assumptions explicitly before working the problem.
- Say what you would check first and why it is the highest-information step.
- 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 do you optimize draw calls and batching in Unity to ensure high performance on lower-end mobile devices?
How do you optimize draw calls and batching in Unity to ensure high performance on lower-end mobile devices?
Approach
- Clarify what is being asked and what a complete answer contains.
- State your assumptions explicitly before working the problem.
- Say what you would check first and why it is the highest-information step.
- 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 ScriptableObjects in Unity, and how would you use them to manage game data or configuration?
What are ScriptableObjects in Unity, and how would you use them to manage game data or configuration?
Approach
- Clarify what is being asked and what a complete answer contains.
- State your assumptions explicitly before working the problem.
- Say what you would check first and why it is the highest-information step.
- 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 design and implement an efficient pathfinding algorithm (such as A*) for a grid-based game board
How would you design and implement an efficient pathfinding algorithm (such as A*) for a grid-based game board?
Approach
- Fix the scope first: who calls this, how often, and what they do when it fails.
- Name the read and write paths separately; they rarely have the same bottleneck.
- Choose a partition key and say what query it makes expensive.
- 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?
Edge instances grow 400 MB per hour until the nightly restart
Edge API instances start at 700 MB resident and grow about 400 MB/hour; a nightly rolling restart has hidden it for weeks. Growth continues unchanged when request rate halves overnight, p99 degrades in the last hours before an instance is recycled, and heap used immediately after a forced full GC rises monotonically. The service holds no product state. Name the discriminating measurement that separates the plausible causes, give the most likely cause, and give the fix and how you would verify it.
Approach
- Separate resident memory from live heap first, because they fail differently. Resident size can grow from fragmentation, native buffers or thread stacks while the heap is flat; heap used after a full GC rising monotonically is the measurement that says objects are reachable and not being released. You already have it, so this is retention, not fragmentation, and that closes off half the candidate list.
- Use the rate's independence from traffic as the discriminator. Growth that continues at half the request rate rules out per-request objects that are merely slow to collect and points at a structure that grows with distinct values observed rather than with call volume. Write the candidates that have that property: a metrics registry keyed on a high-cardinality label, an unevicted cache, an interner, a per-key lock map.
- Take two heap snapshots an hour apart and diff by retained size, reading the dominator tree, not by allocation count or instance count. Expect one root holding a map with millions of entries, then follow the reference chain to the code that inserts and never removes. Allocation profilers point at churn, which is the wrong signal here.
- The candidate that fits this service is an observability label carrying an identifier, such as a request path recorded before templating so that /v1/resources/48213 becomes its own metric series. That grows with distinct ids seen, is independent of rate, and explains the late p99 degradation, since GC cost rises with the size of the live set.
Follow-up
- Post-GC heap is now flat but resident size still creeps. What are you looking at, and does it matter?
- How would you have detected this before an OOM, given the nightly restart masked the trend?
Built from the rounds and topics Product & Design candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the Product & Design loop
- Write out the reported sequence: Conversational Screening Call, Technical Evaluations, Algorithmic Testing, Collaborative Coding Sessions, Deep Technical Discussions, Behavioral Preparation.
- 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 7 reported rounds, with the weakest marked.
02Work Algorithms
- Spend the session on Algorithms, which Product & Design candidates report being tested on.
- Write one worked example in Algorithms and time yourself on it.
Deliverable: One timed worked example in Algorithms.
03Work Data Structures
- Spend the session on Data Structures, which Product & Design candidates report being tested on.
- Write one worked example in Data Structures and time yourself on it.
Deliverable: One timed worked example in Data Structures.
04Work Problem Solving
- Spend the session on Problem Solving, which Product & Design candidates report being tested on.
- Write one worked example in Problem Solving and time yourself on it.
Deliverable: One timed worked example in Problem Solving.
05Answer out loud: Object-Oriented Programming (OOP) & Language Fundamentals
- Answer aloud, timed: Explain the four main pillars of Object-Oriented Programming and how you have applied them in your past projects.
- Answer aloud, timed: What is the difference between a class and a struct in C#, and how do they impact memory allocation (stack vs. heap)?
Deliverable: Spoken answers to 2 reported Object-Oriented Programming (OOP) & Language Fundamentals question(s), under time.
06Answer out loud: Unity & Game Development Concepts
- Answer aloud, timed: Describe the Unity MonoBehaviour lifecycle, specifically highlighting the difference between Awake, Start, Update, and FixedUpdate.
- Answer aloud, timed: How do you optimize draw calls and batching in Unity to ensure high performance on lower-end mobile devices?
Deliverable: Spoken answers to 2 reported Unity & Game Development Concepts question(s), under time.
07Answer out loud: Algorithms & Data Structures
- Answer aloud, timed: Implement a function to detect a cycle in a linked list.
- Answer aloud, timed: Given an array of integers, find the contiguous subarray which has the largest sum (Kadane’s Algorithm).
Deliverable: Spoken answers to 2 reported Algorithms & Data Structures question(s), under time.
Expand any day for tasks and deliverables. Your progress is saved on this device.
Behavioural rounds judge the decision you made and what it cost.
How do you handle physics calculations in Unity to prevent performance bottlenecks?
How do you handle physics calculations in Unity to prevent performance bottlenecks?
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- 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 had a technical disagreement with a teammate. How did you resolve it and reach a cons
Describe a time when you had a technical disagreement with a teammate. How did you resolve it and reach a consensus?
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- 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 challenging bug you encountered in production. How did you diagnose, debug, and ultimately res
Tell me about a challenging bug you encountered in production. How did you diagnose, debug, and ultimately resolve it?
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- 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 balance the pressure of meeting tight launch deadlines with the need to maintain clean, technical d
How do you balance the pressure of meeting tight launch deadlines with the need to maintain clean, technical debt-free code?
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- 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 Product Madness, and what excites you about the social mobile gaming space?
Why do you want to work at Product Madness, and what excites you about the social mobile gaming space?
Approach
- Pick a story where you made the decision, not one where you watched it.
- State the situation in two sentences and spend the rest on the reasoning.
- Give the blast radius: what could have broken, and what you measured.
- 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?
- 01
How do you handle physics calculations in Unity to prevent performance bottlenecks?
- 02
Describe a time when you had a technical disagreement with a teammate. How did you resolve it and reach a consensus?
- 03
Tell me about a challenging bug you encountered in production. How did you diagnose, debug, and ultimately resolve it?
- 04
How do you balance the pressure of meeting tight launch deadlines with the need to maintain clean, technical debt-free code?
How difficult is the interview process at Product Madness?
Candidates generally describe the interview process as average in difficulty. The technical tests are highly relevant to everyday game development tasks, focusing on practical coding, OOP concepts, and algorithmic problem-solving rather than obscure academic puzzles.
Product & Design Software Engineer candidate reports ↗What is the typical timeline from application to offer?
The process is exceptionally fast. Many candidates report completing the entire process—including the initial screen, technical test, final round, and receiving an offer—in less than a single week.
Product & Design Software Engineer candidate reports ↗What programming languages can I use in the technical test?
The online coding platform used by Product Madness typically allows you to choose your preferred language, with C# and C++ being the most common and highly recommended choices for engineering candidates.
Product & Design Software Engineer candidate reports ↗Is there a cultural fit component to the interview?
Yes, cultural alignment is highly valued. The final rounds almost always include conversations focused on your collaboration style, passion for gaming, and how you handle feedback and teamwork in a fast-paced environment.
Product & Design Software Engineer candidate reports ↗Does Product Madness offer remote or hybrid work options?
Yes, the company generally offers flexible hybrid work arrangements depending on the office location (such as London or Montreal), allowing engineers to balance in-office collaboration with remote productivity.
Product & Design Software Engineer candidate reports ↗What topics does Product & Design test in interviews?
Product & Design interviews most often cover SQL, Python, Interview process comprehension, Problem Solving, and Communication skills. The exact emphasis depends on the specific role you apply for.
Product & Design Software Engineer candidate reports ↗Sources & methodology 3 sources ↗
Official role evidence, timestamped platform data and clearly labeled preparation advice.
- 01Product & Design Software Engineer candidate reports ↗
Company-reported rounds, questions and FAQ.
candidate · Accessed 2026-09-22 - 02PracHub Software Engineer practice ↗
PracHub practice material, not company-reported.
platform · Accessed 2026-09-22 - 03PracHub preparation framework ↗
PracHub preparation guidance.
platform · Accessed 2026-09-22
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