As a Software Engineer at Brain, you will play a pivotal role in developing innovative software solutions that drive the company's mission forward. This position is essential for creating products that leverage artificial intelligence, machine learning, and sophisticated algorithms to enhance the autonomy of machines and systems. Your contributions will directly impact the usability and effectiveness of Brain's offerings, enabling users to interact seamlessly with technology in their everyday lives. In this role, you will work closely with cross-functional teams, including product management, data scientists, and hardware engineers, to solve complex problems and implement cutting-edge technology. The work is dynamic and challenging, involving both project-based and exploratory tasks where you'll have the opportunity to shape the future of autonomy and robotics. Expect to engage with real-world applications that require not only strong technical skills but also creativity and strategic thinking.
Initial Phone Screen
reportedAn initial screening call to assess candidate fit and discuss the role.
What to demonstrate
- An initial screening call to assess candidate fit and discuss the role
- Depth in Machine Learning
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
reportedCandidates undergo technical assessments to evaluate their software engineering skills.
What to demonstrate
- Candidates undergo technical assessments to evaluate their software engineering skills
- Depth in Machine Learning
How to prepare
- Answer aloud and timed: Describe how you would design a scalable web service.
- Answer aloud and timed: What are the key advantages of using a microservices architecture?
On-site Interview
reportedA comprehensive on-site interview that includes coding tasks and discussions on system design.
What to demonstrate
- A comprehensive on-site interview that includes coding tasks and discussions on system design
- Depth in Machine Learning
How to prepare
- Answer aloud and timed: How would you optimize a slow-running query in a database?
- Answer aloud and timed: Write a function to reverse a linked list.
PracHub editorial advice for the preparation topics above.
Practice coding under time constraints
Familiarize yourself with coding challenges to improve your speed and accuracy.
Engage in mock interviews
Conduct practice interviews with peers or use platforms that simulate technical interviews.
Research Brain's products and culture
Understanding the company’s mission and projects can help you tailor your answers and demonstrate your enthusiasm.
Be prepared for behavioral questions
Reflect on your past experiences and be ready to discuss them in a structured manner (Situation, Task, Action, Result).
Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.
Explain how you would implement a binary search algorithm.
Explain how you would implement a binary search 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?
Write a function to reverse a linked list.
Write a function to reverse 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 two numbers such that they add up to a specific target.
Given an array of integers, find two numbers such that they add up to a specific target.
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?
Implement a function to check if a string is a palindrome.
Implement a function to check if a string is a palindrome.
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?
Describe the time complexity of your solution.
Describe the time complexity of your solution.
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?
How would you optimize a slow-running query in a database?
How would you optimize a slow-running query in a database?
Approach
- Name the grain you start from and join outward from it.
- Check whether any join is one-to-many before aggregating, or the sums inflate.
- Say which index the query would use, and what makes it unusable.
- 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 the update path that detects a concurrent edit
resource carries version INT NOT NULL DEFAULT 1. resource_revision holds revision_id, resource_id, version, actor_user_id, change_kind, patch JSONB, request_id, created_at with UNIQUE (resource_id, version). outbox_event holds aggregate_type, aggregate_id, aggregate_version, event_type, payload, status. A PUT carries the version the client read. Write the exact statements for the single transaction that applies the edit, records the revision and enqueues 'resource.updated', and give the handler's branch on zero affected rows. Then say what PostgreSQL 16 does under READ COMMITTED when two of these updates hit one row at once.
Approach
- One transaction, three writes, no network call inside it: UPDATE resource SET title = $3, version = version + 1, updated_at = now() WHERE resource_id = $1 AND tenant_id = $4 AND version = $2; then INSERT the resource_revision row at version $2 + 1; then INSERT the outbox_event row at the same aggregate_version. The event goes to a table rather than a broker because no transaction spans both.
- Branch on the affected-row count before doing anything else. Zero has three causes — stale version, wrong tenant, row gone — so re-read once and map to 409 carrying the current version, or 404 for an id outside the caller's tenant, which also stops the endpoint confirming that another tenant's id exists.
- State the engine behaviour instead of assuming it. Under READ COMMITTED the second UPDATE blocks on the row lock, and when the first commits PostgreSQL re-evaluates the WHERE clause against the newly committed row, so the version predicate now fails and the statement reports zero rows. Under REPEATABLE READ the identical collision raises SQLSTATE 40001 instead, so the handler must fold both shapes into one conflict response.
- Keep UNIQUE (resource_id, version) even though the predicate already serialises writers. It is what makes a lost update unwritable if any other path ever reaches the revision table, and it converts a logic bug into 23505 rather than into a silently missing history row.
Follow-up
- A client sends the version it read ten minutes ago and the resource has moved three versions. What is in your 409 so it can resolve the conflict without a full re-fetch?
- Two editors, two disjoint fields, no overlap. Does your answer still refuse the second write, and should it?
What is the difference between a stack and a queue?
What is the difference between a stack and a queue?
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?
Describe how you would design a scalable web service.
Describe how you would design a scalable web service.
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?
What are the key advantages of using a microservices architecture?
What are the key advantages of using a microservices 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?
How would you design a system for real-time data processing?
How would you design a system for real-time data processing?
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 considerations you would take into account when building a distributed system.
Describe the considerations you would take into account when building a distributed system.
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?
What strategies would you use to ensure high availability and fault tolerance in a service?
What strategies would you use to ensure high availability and fault tolerance in a service?
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?
If you were tasked with improving the user experience of a product, what steps would you take?
If you were tasked with improving the user experience of a product, what steps would you take?
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 approach debugging a production issue?
How would you approach debugging a production issue?
Approach
- Establish what changed and when, before forming any theory.
- Pick a bisection that eliminates candidates whichever way it turns out.
- Check the instrumentation before believing the symptom.
- 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?
Built from the rounds and topics Brain candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the Brain loop
- Write out the reported sequence: Initial Phone Screen, Technical Assessments, On-site Interview.
- 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.
02Work Machine Learning
- Spend the session on Machine Learning, which Brain candidates report being tested on.
- Write one worked example in Machine Learning and time yourself on it.
Deliverable: One timed worked example in Machine Learning.
03Work Deep Learning
- Spend the session on Deep Learning, which Brain candidates report being tested on.
- Write one worked example in Deep Learning and time yourself on it.
Deliverable: One timed worked example in Deep Learning.
04Work Reinforcement Learning (RL)
- Spend the session on Reinforcement Learning (RL), which Brain candidates report being tested on.
- Write one worked example in Reinforcement Learning (RL) and time yourself on it.
Deliverable: One timed worked example in Reinforcement Learning (RL).
05Answer out loud: Technical / Domain Questions
- Answer aloud, timed: What is the difference between a stack and a queue?
- Answer aloud, timed: Explain how you would implement a binary search algorithm.
Deliverable: Spoken answers to 2 reported Technical / Domain Questions question(s), under time.
06Answer out loud: Coding / Algorithms
- Answer aloud, timed: Write a function to reverse a linked list.
- Answer aloud, timed: Given an array of integers, find two numbers such that they add up to a specific target.
Deliverable: Spoken answers to 2 reported Coding / Algorithms question(s), under time.
07Answer out loud: Behavioral / Leadership
- Answer aloud, timed: Tell me about a time you faced a significant challenge at work and how you overcame it.
- Answer aloud, timed: Describe a project where you had to work closely with others. What was your role?
Deliverable: Spoken answers to 2 reported Behavioral / Leadership 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.
Tell me about a time you faced a significant challenge at work and how you overcame it.
Tell me about a time you faced a significant challenge at work and how you overcame 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?
Describe a project where you had to work closely with others. What was your role?
Describe a project where you had to work closely with others. What was your role?
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 prioritize tasks when you have multiple deadlines?
How do you prioritize tasks when you have multiple deadlines?
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
Tell me about a time you faced a significant challenge at work and how you overcame it.
- 02
Describe a project where you had to work closely with others. What was your role?
- 03
How do you prioritize tasks when you have multiple deadlines?
What is the typical difficulty level of the interviews?
The interviews at Brain can range from average to difficult, depending on the position and specific team. Candidates should prepare for a rigorous process that includes technical assessments and behavioral questions.
Brain Software Engineer candidate reports ↗What differentiates successful candidates?
Successful candidates typically demonstrate strong technical expertise, clear communication, and a collaborative mindset. They are able to articulate their problem-solving processes and align their experiences with the company’s values.
Brain Software Engineer candidate reports ↗What is the culture and working style at Brain?
The culture at Brain is collaborative and innovation-driven. Employees are encouraged to share ideas and work together to solve complex challenges, fostering an environment of continuous learning.
Brain Software Engineer candidate reports ↗What is the typical timeline from initial screen to offer?
The timeline can vary, but candidates usually hear back within a few weeks after the initial screening. Be prepared for multiple rounds of interviews that may extend over several weeks.
Brain Software Engineer candidate reports ↗Are there remote work or hybrid expectations?
Brain has embraced flexible work arrangements, and candidates should inquire about specific policies during the interview process.
Brain Software Engineer candidate reports ↗What topics does Brain test in interviews?
Brain interviews most often cover Python, Coding Assignments, Unit Testing, Hiring Manager Collaboration, and Algorithms. The exact emphasis depends on the specific role you apply for.
Brain Software Engineer candidate reports ↗Sources & methodology 3 sources ↗
No official company page is cited. Rounds and questions come from candidate reports and PracHub editorial material; each source shows the date it was read.
- 01Brain Software Engineer candidate reports ↗
Company-reported rounds, questions and FAQ.
Candidate reports · Accessed 2026-09-22 - 02PracHub Software Engineer practice ↗
PracHub practice material, not company-reported.
PracHub page · Accessed 2026-09-22 - 03PracHub preparation framework ↗
PracHub preparation guidance.
PracHub page · Accessed 2026-09-22
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