As a Software Engineer at Kinexcs, you play a pivotal role in bridging the gap between cutting-edge digital health technology and clinical outcomes. You are not just writing code; you are building the digital infrastructure that empowers physical therapy and patient rehabilitation. Your contributions directly impact the scalability and reliability of Kinexcs products, which are designed to track movement and provide actionable insights for users and clinicians alike. This position demands a blend of technical rigor and a passion for health-tech innovation. You will navigate complex problem spaces, from data processing to user-facing application development, ensuring that our software remains performant and user-centric. Expect a fast-paced environment where your work has immediate visibility and your ability to translate clinical needs into robust software solutions is highly valued.
Initial Conversation
reportedStart with a conversation with a Product Owner or hiring lead to introduce the company mission and role scope.
What to demonstrate
- Start with a conversation with a Product Owner or hiring lead to introduce the company mission and role scope
- Depth in Interview Process (Product/Technical Rounds)
How to prepare
- Answer aloud and timed: Can you walk me through your process for debugging a complex system issue?
- Answer aloud and timed: How do you ensure your code is both scalable and maintainable?
Technical Assessment
reportedA technical assessment to validate coding and architectural skills, often with an external provider.
What to demonstrate
- A technical assessment to validate coding and architectural skills, often with an external provider
- Depth in Interview Process (Product/Technical Rounds)
How to prepare
- Answer aloud and timed: What is your experience with the specific tech stack mentioned in our internal documentation?
- Answer aloud and timed: How do you approach testing to ensure high software reliability?
Final Interview Round
reportedIn-depth interview via video conference or in person to discuss technical approach and behavioral traits.
What to demonstrate
- In-depth interview via video conference or in person to discuss technical approach and behavioral traits
- Depth in Interview Process (Product/Technical Rounds)
How to prepare
- Answer aloud and timed: Describe a time you had to explain a complex technical hurdle to a team member from a different department.
- Answer aloud and timed: How do you handle disagreements regarding technical architecture or implementation?
PracHub editorial advice for the preparation topics above.
Understand the Product
Spend time researching what Kinexcs does. Understanding our mission in physical therapy will make your answers much more compelling.
Be Transparent
If you don't know an answer, it is better to explain how you would find the solution rather than guessing.
Think Out Loud
During technical assessments, your thought process is as important as the final code.
Clarify Expectations
Always ask clarifying questions if a prompt seems ambiguous. This shows you are a thoughtful engineer who values accuracy.
Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.
Find overlapping job attempts and peak concurrency from lease records
A day of job_run history yields about 50,000,000 attempt records: (job_run_id, job_type, attempt, started_at, finished_at which is NULL when the worker died, lease_expires_at). Leases expire on a clock, so a job that outran its lease ran twice. Produce (a) every job_run_id whose attempts overlapped in wall-clock time and (b) the peak number of simultaneously running attempts per job_type with the minute it occurred. Target O(n log n). State how you treat a NULL finished_at and what clock skew does to your answer.
Approach
- Define the interval before sorting anything: an attempt occupies [started_at, COALESCE(finished_at, lease_expires_at)). finished_at is observed and lease_expires_at is only a promise, so every attempt without a finish contributes an estimate and the whole result is a lower bound on overlap rather than an exact count.
- For peak concurrency, sweep: emit 2n endpoints, sort by (timestamp, kind) with ends ordered before starts at equal timestamps, then walk the sequence maintaining a counter per job_type and record each type's maximum with its timestamp. O(n log n) dominated by the sort, O(n) space, or O(1) extra if the sort is external and the walk streams.
- For overlap detection, do not compare attempts pairwise. A single global sort by (job_run_id, started_at) gives both the grouping and the order; within a group, keep the maximum end seen so far and report an overlap exactly when the next start is less than that running maximum, which is one linear pass after the sort.
- Half-open intervals matter and are easy to get wrong: with closed intervals an attempt ending at the same millisecond another begins reads as concurrency two, and across 50,000,000 records that artefact swamps the real signal.
Follow-up
- A handler is not idempotent and you have found 400 overlapping jobs. Which of them actually caused damage, and what would you query to find out?
- Peak concurrency for one job_type is 4 against a configured cap of 4. Is the cap working, or is the data hiding attempts that never started?
Track a rolling failure rate per destination for circuit decisions
The egress service delivers about 1,500 webhooks per second across roughly 40,000 destinations, each call bounded by a 10 second timeout. Maintain, per destination, the failure rate over the trailing 60 seconds so a caller can ask before dispatch whether the circuit should open. Attempts arrive as (destination_id, finished_at_ms, outcome). Requirement: amortised O(1) per attempt, with total memory bounded by the destination count rather than by traffic. Give the structure, its exact memory, and the rule that stops a destination with three attempts from opening a circuit.
Approach
- Name the exact-deque version and then reject it as the default. Holding timestamps and advancing a tail pointer past anything older than now minus 60 seconds is a correct two-pointer window at amortised O(1) per attempt, but its memory tracks in-window traffic, so one destination in a retry storm holds hundreds of thousands of entries while thousands of quiet destinations hold none.
- Use a ring of 60 one-second buckets per destination, each bucket a pair of counters for attempts and failures. On an attempt, advance the ring by the elapsed whole seconds, zeroing at most min(elapsed, 60) buckets, then increment the head. That is amortised O(1) with a fixed footprint per destination.
- State the footprint: 60 buckets times two 4-byte counters is 480 bytes of payload per destination, so 40,000 destinations is roughly 20 to 25 MB with per-entry overhead, bounded by the catalogue rather than by the rate. The cost is granularity, since the oldest bucket ages out in whole seconds, which is far tighter than the decision needs.
- Require a minimum sample before the circuit may open. A destination with three attempts and three failures reads as 100 percent and is not evidence; a floor of roughly 20 attempts in the window makes the ratio meaningful, and below that floor use a run of consecutive failures as the trigger instead.
Follow-up
- The fleet is 30 instances and each sees roughly a thirtieth of a destination's traffic. Where does the rate actually live, and what does a per-instance answer get wrong?
- A destination answers in 9.5 seconds and succeeds. It is not failing but it is consuming your per-destination concurrency. What signal should open the circuit here?
Diff a projection against the primary without per-row point reads
The listing projection has drifted and some rows show a stale version. The primary holds 40,000,000 resource rows across 12,000 tenants while serving 1,200 writes and 14,000 reads per second. The obvious repair, reading each resource row and comparing its version against the projection, is correct and would eventually finish. Explain precisely why it is unacceptable here, then give a diff that finds the differing rows, state its complexity, and make it safe to run against a live primary. Replication lag is usually under 100 ms and is not bounded.
Approach
- Quantify the naive cost rather than calling it slow: 40,000,000 point reads at even 0.5 ms each is over five hours serialised, and the only lever is concurrency, which is exactly what you cannot spend. The primary's pool is sized for the write path, and 40,000,000 random reads evict the buffer cache that sustains the 85 percent cache hit rate, so the audit degrades the system it is auditing.
- Replace random access with one ordered pass per side. Both sides can be read in (tenant_id, resource_id) order, which is a sequential scan on each and a merge join in O(n) time and O(1) memory. For a dense diff that is the whole answer, and it reads the primary once instead of 40,000,000 times.
- For the expected sparse case, compare range hashes instead of rows: partition the key space, compute per range an order-independent aggregate over hash(resource_id, version), compare aggregates, and descend only into ranges that differ. With d differing rows and branching factor B, at most d ranges mismatch per level, so the drill-down examines O(d log_B(n/d)) ranges and reads full rows only in mismatching leaves.
- Aggregate with a sum modulo 2^64 or a multiset hash, never XOR. XOR is order-independent but self-cancelling, so two rows wrong in the same way, or a row duplicated on one side, leave the range aggregate matching and the range is declared clean.
Follow-up
- The diff reports 900 stale rows. How do you decide between patching those rows and rebuilding the projection from resource_revision?
- Same job, but the projection lives in a search index that cannot be scanned in key order. What changes?
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?
Find version gaps and relay lag with window functions
outbox_event holds event_id, aggregate_type, aggregate_id, aggregate_version, event_type, payload, status ('pending','published','dead'), attempts, created_at, published_at. A projection is missing rows and you must decide whether the relay skipped events or the consumer dropped them. Write three queries over the last seven days: one listing every aggregate_id whose published aggregate_version sequence has a hole, one giving per-day counts with a running total, and one returning the newest published event per aggregate. For each, say where the window function is evaluated relative to WHERE and LIMIT. PostgreSQL 16.
Approach
- Gaps: compute lead(aggregate_version) OVER (PARTITION BY aggregate_id ORDER BY aggregate_version) in a subquery, then filter next_version <> aggregate_version + 1 in the outer query. Window functions are evaluated after WHERE, GROUP BY and HAVING and before the outer ORDER BY and LIMIT, so the predicate cannot sit in the same WHERE clause and PostgreSQL 16 has no QUALIFY.
- Say what the seven-day filter does to the answer: it truncates every partition, so the first row per aggregate has no predecessor inside the window and a hole spanning the boundary is invisible. Widen the window, or join to resource.version as the authority for the true maximum.
- Running total: SELECT date_trunc('day', created_at) AS d, count() AS n, sum(count()) OVER (ORDER BY date_trunc('day', created_at) ROWS UNBOUNDED PRECEDING). An aggregate inside a window call is legal because grouping runs before windowing. The grouping key is unique per row here so ROWS and RANGE agree, but write the frame anyway — over ungrouped rows with tied timestamps the default RANGE frame pulls in every peer row and the total jumps.
- Newest per aggregate: DISTINCT ON (aggregate_id) ... ORDER BY aggregate_id, aggregate_version DESC is the cheap PostgreSQL-only form when an index matches that order; row_number() OVER (PARTITION BY aggregate_id ORDER BY aggregate_version DESC) = 1 is the portable form and needs a subquery for the same evaluation-order reason as the gap query.
Follow-up
- Relay failover redelivers events. Does a duplicate break the gap query, and how would you detect one from this table alone?
- Turn the gap check into a continuous monitor rather than a query someone runs after an incident. What does it watch?
How do you ensure your code is both scalable and maintainable?
How do you ensure your code is both scalable and maintainable?
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 do you approach testing to ensure high software reliability?
How do you approach testing to ensure high software reliability?
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 a challenging technical project you led from inception to deployment.
Walk me through a challenging technical project you led from inception to deployment.
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 prioritize your tasks when faced with multiple urgent requests?
How do you prioritize your tasks when faced with multiple urgent requests?
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?
If you found a critical bug in production, what are the first three steps you would take?
If you found a critical bug in production, what are the first three steps you would 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?
Can you walk me through your process for debugging a complex system issue?
Can you walk me through your process for debugging a complex system 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 Kinexcs candidates report.
Prepare, practise & reflect
One practical outcome each day. Spend longer where you need it.
0 / 7 done01Map the Kinexcs loop
- Write out the reported sequence: Initial Conversation, Technical Assessment, Final Interview Round.
- 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 Interview Process (Product/Technical Rounds)
- Spend the session on Interview Process (Product/Technical Rounds), which Kinexcs candidates report being tested on.
- Write one worked example in Interview Process (Product/Technical Rounds) and time yourself on it.
Deliverable: One timed worked example in Interview Process (Product/Technical Rounds).
03Work Problem Solving (General)
- Spend the session on Problem Solving (General), which Kinexcs candidates report being tested on.
- Write one worked example in Problem Solving (General) and time yourself on it.
Deliverable: One timed worked example in Problem Solving (General).
04Work Technical Interview Preparation
- Spend the session on Technical Interview Preparation, which Kinexcs candidates report being tested on.
- Write one worked example in Technical Interview Preparation and time yourself on it.
Deliverable: One timed worked example in Technical Interview Preparation.
05Answer out loud: Technical & Domain Knowledge
- Answer aloud, timed: Can you walk me through your process for debugging a complex system issue?
- Answer aloud, timed: How do you ensure your code is both scalable and maintainable?
Deliverable: Spoken answers to 2 reported Technical & Domain Knowledge question(s), under time.
06Answer out loud: Behavioral & Communication
- Answer aloud, timed: Describe a time you had to explain a complex technical hurdle to a team member from a different department.
- Answer aloud, timed: How do you handle disagreements regarding technical architecture or implementation?
Deliverable: Spoken answers to 2 reported Behavioral & Communication question(s), under time.
07Answer out loud: Problem-Solving & Process
- Answer aloud, timed: Walk me through a challenging technical project you led from inception to deployment.
- Answer aloud, timed: How do you prioritize your tasks when faced with multiple urgent requests?
Deliverable: Spoken answers to 2 reported Problem-Solving & Process 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.
What is your experience with the specific tech stack mentioned in our internal documentation?
What is your experience with the specific tech stack mentioned in our internal documentation?
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 you had to explain a complex technical hurdle to a team member from a different department.
Describe a time you had to explain a complex technical hurdle to a team member from a different department.
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 disagreements regarding technical architecture or implementation?
How do you handle disagreements regarding technical architecture or implementation?
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 us about a project where you had to pivot quickly due to changing requirements.
Tell us about a project where you had to pivot quickly due to changing requirements.
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
What is your experience with the specific tech stack mentioned in our internal documentation?
- 02
Describe a time you had to explain a complex technical hurdle to a team member from a different department.
- 03
How do you handle disagreements regarding technical architecture or implementation?
- 04
Tell us about a project where you had to pivot quickly due to changing requirements.
How difficult are the technical assessments?
The assessments are designed to be accessible to experienced engineers, focusing on practical problem-solving rather than obscure theory. If you have a solid grasp of your primary language and fundamental data structures, you will be well-prepared.
Kinexcs Software Engineer candidate reports ↗What is the typical timeline from the first interview to an offer?
We aim to keep the process efficient; many candidates receive feedback within one week of their final interview.
Kinexcs Software Engineer candidate reports ↗Does Kinexcs support remote work?
Our team culture relies heavily on collaboration, so we generally prefer candidates based in Singapore, though we encourage you to discuss specific location expectations with your recruiter.
Kinexcs Software Engineer candidate reports ↗What differentiates a successful candidate?
Successful candidates are those who show curiosity, ask insightful questions about our product's impact, and demonstrate a clear ability to balance technical perfection with project deadlines.
Kinexcs Software Engineer candidate reports ↗What topics does Kinexcs test in interviews?
Kinexcs interviews most often cover Computer Vision, Human Pose Estimation, Interview Process (Product/Technical Rounds), Sensor Fusion (Vision + IMU), and Machine Learning. The exact emphasis depends on the specific role you apply for.
Kinexcs 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.
- 01Kinexcs 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
Explore related engineering environments and compare the preparation focus.
Cognition Software Engineer Interview Guide
What Cognition asks Software Engineer candidates, from reported rounds and questions.
Vercel Software Engineer Interview Guide
Debugging practice for Vercel software engineer prep built on a reproduction you trust, narrowing to the smallest failing input, and changing one variable per run so the result stays attributable.
Together Ai Software Engineer Interview Guide
Failure-handling practice for Together Ai software engineer candidates: requests whose outcome a timeout leaves unknown, where a retry is safe, and deduplicating at the receiver instead of assuming exactly-once delivery.
Spotify Software Engineer Interview Guide
Timed practice for Spotify software engineer candidates who lose time to the clock: short problems taken end to end, then reviewed against a written rubric rather than a passing test run.