As a Software Engineer at Spin, you play a pivotal role in shaping the future of urban mobility. Your contributions directly impact the design, development, and deployment of software systems that power Spin’s innovative mobility solutions. This role is crucial for enhancing user experience, ensuring operational efficiency, and driving the technology that supports Spin's mission of creating accessible and sustainable transportation options. In this dynamic environment, you'll collaborate with cross-functional teams to solve complex problems, architect scalable solutions, and implement features that delight users. Your work will influence various product lines, from mobile applications to backend services, making this role both strategically important and technically challenging. Expect to engage with cutting-edge technologies and methodologies, all while contributing to a mission that promotes smarter and greener cities.
Initial Screening
reportedAn initial screening with a recruiter to discuss the candidate's background and fit for the role.
What to demonstrate
- An initial screening with a recruiter to discuss the candidate's background and fit for the role
- Depth in Virtual Onsite Interview
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 Interview
reportedA technical interview, often conducted via video call, focusing on coding challenges and system design.
What to demonstrate
- A technical interview, often conducted via video call
- Focusing on coding challenges and system design
How to prepare
- Answer aloud and timed: Describe a time you optimized a piece of code. What was the impact?
- Answer aloud and timed: What are your strategies for ensuring code quality and maintainability?
Virtual Onsite
reportedA final stage where candidates meet with various team members and stakeholders in a virtual setting.
What to demonstrate
- A final stage where candidates meet with various team members and stakeholders in a virtual setting
- Depth in Virtual Onsite Interview
How to prepare
- Answer aloud and timed: Explain the concept of microservices and their advantages.
- Answer aloud and timed: Describe a challenge you faced in a team project and how you resolved it.
PracHub editorial advice for the preparation topics above.
Be prepared to showcase your projects
Discuss your past work in detail, highlighting your contributions and the impact they had.
Practice coding problems regularly
Use platforms like LeetCode or HackerRank to sharpen your skills and gain familiarity with common coding challenges.
Research Spin’s products and mission
Understanding the company’s goals and values will help you align your responses with what they seek in candidates.
Engage with your interviewers
Show interest in their experiences and perspectives, which can lead to a more engaging conversation.
Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.
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, find the two numbers that add up to a specific target.
Given an array, find the two numbers that 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?
How would you implement a binary search algorithm?
How would you 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?
Explain the time complexity of your solution for a recent coding challenge.
Explain the time complexity of your solution for a recent coding challenge.
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?
Stop tag and share joins from fanning out a page
resource_tag is (resource_id, tag_id) with PK (resource_id, tag_id); resource_share is (resource_id, shared_with_user_id, permission). The tagged-and-shared listing inner-joins resource to both, filters tenant_id, tag_id = ANY($2) and shared_with_user_id = $3, orders by updated_at DESC and takes 50. Pages come back with fewer than 50 distinct resources and the total in the header is far too high. Explain the row multiplication, rewrite both the page query and the count query so each is correct, and name the index each one needs. PostgreSQL 16.
Approach
- Do the arithmetic against the predicates that are actually there. An inner join emits one row per matching child row, and both joins are filtered: tag_id = ANY($2) admits only the requested tags, shared_with_user_id = $3 admits one user's share rows. So a resource holding three of the requested tags and shared with $3 once yields three rows, not one — the multiplier is its count of matching tags times its share rows for that single user, and that second factor is 1 unless the table admits duplicate (resource_id, shared_with_user_id) pairs. LIMIT 50 then limits rows rather than resources, and COUNT(*) counts pairs — the header is the product, not the population.
- Reject DISTINCT as the fix. It deduplicates after the product has been built, so the planner must materialise and sort the fanned-out set before the LIMIT can apply, and it leaves any SUM or AVG in the same select list wrong.
- Rewrite both filters as semi-joins, keeping resource as the only row source: AND EXISTS (SELECT 1 FROM resource_tag rt WHERE rt.resource_id = r.resource_id AND rt.tag_id = ANY($2)) and the same shape against resource_share. A semi-join stops at the first match per resource and preserves the driving index order, so ORDER BY updated_at DESC, resource_id DESC LIMIT 50 still stops after 50 rows.
- Count with the same predicates and no join at all: SELECT count(*) FROM resource r WHERE r.tenant_id = $1 AND r.status = 'active' AND EXISTS (...) AND EXISTS (...). Nothing multiplies a resource, so the number is the population.
Follow-up
- The filter changes from 'any of these tags' to 'all of these tags'. Rewrite it and state what it costs relative to the ANY form.
- A resource can be shared with the same user twice under different permissions. Does your count change, and should it?
Denormalise tenant onto revisions and backfill it live
resource_revision (revision_id, resource_id, version, actor_user_id, change_kind, patch, request_id, created_at) has 400M rows and no tenant column; tenant_id lives only on resource. Two reads need it: a tenant-scoped audit feed ordered by created_at DESC, and an offboarding purge. Both join back to resource today. Justify adding tenant_id to resource_revision against those two reads, name the anomaly the copy introduces and the constraint that prevents it, then give the ordered migration for a live table taking 1.2k writes/second — the lock each step takes, how the backfill is batched, and where each step stops being reversible. PostgreSQL 16.
Approach
- Justify from the access path rather than from taste. Without the column, the audit feed either scans resource_revision by created_at and discards other tenants' rows, or resolves the tenant's resource_ids first and probes with them — both proportional to the tenant's whole history rather than to one page. With (tenant_id, created_at DESC, revision_id DESC) it is a seek that stops at 50 rows, and the purge becomes a ranged delete instead of a join.
- Name the cost exactly: a second copy of a fact can disagree with the first. Make the disagreement unwritable rather than documented — add UNIQUE (resource_id, tenant_id) on resource so it can serve as a foreign-key target, then FOREIGN KEY (resource_id, tenant_id) REFERENCES resource (resource_id, tenant_id) on the revision table. A revision can then only ever carry its parent's tenant.
- Step one, expand: ALTER TABLE resource_revision ADD COLUMN tenant_id BIGINT NULL, with no default, so it is a catalogue change and no rewrite. It still needs ACCESS EXCLUSIVE for an instant, and that instant queues behind the longest open transaction on the table while every later query queues behind it — set lock_timeout to 2s and retry rather than wait.
- Step two, dual-write: deploy the writer that populates tenant_id on every new revision while reads still use the join. Reversible by redeploying the previous build, because nothing reads the column yet.
Follow-up
- The backfill is half finished and a rollback is required. What state is the table in, and what does the previous build do with a half-populated column?
- How do you verify the backfill actually finished, given rows are still being inserted while it runs?
Can you explain the differences between REST and GraphQL?
Can you explain the differences between REST and GraphQL?
Approach
- Say who the caller is and what they do when the call fails halfway.
- Define the identity of a request so a retry cannot double-apply it.
- Separate accepted, pending, failed and confirmed; they are different facts.
- 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?
What are your strategies for ensuring code quality and maintainability?
What are your strategies for ensuring code quality and maintainability?
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?
Explain the concept of microservices and their advantages.
Explain the concept of microservices and their advantages.
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 to handle millions of user requests?
How would you design a system to handle millions of user requests?
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 tasked with improving an existing application, what metrics would you consider?
If tasked with improving an existing application, what metrics would you consider?
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?
Walk me through your thought process for a recent technical problem you solved.
Walk me through your thought process for a recent technical problem you solved.
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 a project where you had to learn a new technology quickly.
Describe a project where you had to learn a new technology quickly.
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 complex system?
How would you approach debugging a complex system?
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 Spin candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the Spin loop
- Write out the reported sequence: Initial Screening, Technical Interview, Virtual Onsite.
- 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 Virtual Onsite Interview
- Spend the session on Virtual Onsite Interview, which Spin candidates report being tested on.
- Write one worked example in Virtual Onsite Interview and time yourself on it.
Deliverable: One timed worked example in Virtual Onsite Interview.
03Work Technical Interview
- Spend the session on Technical Interview, which Spin candidates report being tested on.
- Write one worked example in Technical Interview and time yourself on it.
Deliverable: One timed worked example in Technical Interview.
04Work Hiring Manager Interview (Zoom)
- Spend the session on Hiring Manager Interview (Zoom), which Spin candidates report being tested on.
- Write one worked example in Hiring Manager Interview (Zoom) and time yourself on it.
Deliverable: One timed worked example in Hiring Manager Interview (Zoom).
05Answer out loud: Technical / Domain Questions
- Answer aloud, timed: How would you approach debugging a complex system?
- Answer aloud, timed: Can you explain the differences between REST and GraphQL?
Deliverable: Spoken answers to 2 reported Technical / Domain Questions question(s), under time.
06Answer out loud: Behavioral / Leadership
- Answer aloud, timed: Describe a challenge you faced in a team project and how you resolved it.
- Answer aloud, timed: How do you handle feedback and criticism?
Deliverable: Spoken answers to 2 reported Behavioral / Leadership question(s), under time.
07Answer out loud: Problem-Solving / Case Studies
- Answer aloud, timed: How would you design a system to handle millions of user requests?
- Answer aloud, timed: If tasked with improving an existing application, what metrics would you consider?
Deliverable: Spoken answers to 2 reported Problem-Solving / Case Studies 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.
Describe a time you optimized a piece of code. What was the impact?
Describe a time you optimized a piece of code. What was the impact?
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 challenge you faced in a team project and how you resolved it.
Describe a challenge you faced in a team project and how you resolved 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 handle feedback and criticism?
How do you handle feedback and criticism?
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?
Give an example of how you influenced team decisions.
Give an example of how you influenced team decisions.
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?
What motivates you to excel in your work?
What motivates you to excel in your work?
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 working under tight deadlines?
How do you prioritize tasks when working under tight 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
Describe a time you optimized a piece of code. What was the impact?
- 02
Describe a challenge you faced in a team project and how you resolved it.
- 03
How do you handle feedback and criticism?
- 04
Give an example of how you influenced team decisions.
What is the interview difficulty like?
The interview difficulty for the Software Engineer role at Spin is generally moderate. Candidates should anticipate a blend of technical and behavioral questions, with an emphasis on practical problem-solving. Preparing for a range of topics will be beneficial.
Spin Software Engineer candidate reports ↗What differentiates successful candidates?
Successful candidates typically demonstrate a strong combination of technical skills, effective communication, and a cultural fit with Spin’s values. They are also able to articulate their thought processes clearly during technical discussions.
Spin Software Engineer candidate reports ↗How does the culture at Spin influence work style?
Spin’s culture emphasizes collaboration, innovation, and a commitment to sustainability. Employees are encouraged to contribute ideas and engage in open communication, fostering an inclusive environment that values diverse perspectives.
Spin Software Engineer candidate reports ↗What is the typical timeline from initial screen to offer?
The process can vary, but candidates can expect to complete the initial screening within one to two weeks, followed by interviews that may take an additional few weeks. Overall, the timeline from application to offer may span 4-6 weeks.
Spin Software Engineer candidate reports ↗Are there remote work opportunities available?
Spin supports flexible work arrangements, including remote and hybrid options, depending on team needs and individual circumstances.
Spin Software Engineer candidate reports ↗What topics does Spin test in interviews?
Spin interviews most often cover Stakeholder Communication, System Design, Problem Solving, Communication Clarity, and SQL. The exact emphasis depends on the specific role you apply for.
Spin 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.
- 01Spin 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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