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Navihealth Software Engineer Interview Guide

Navihealth Software Engineer interview guide: reported rounds, questions and how candidates describe the process.

The 60-second brief

A Software Engineer at Navihealth plays a critical role in developing and scaling technologies that directly impact post-acute care management and clinical decision support. The applications you build and maintain enable healthcare providers, coordinators, and health plans to make data-driven decisions, ensuring patients transition from hospitals to post-acute care settings safely and efficiently. By working on these platforms, your code directly influences patient outcomes and helps optimize the delivery of healthcare services across the nation. In this role, you are not just writing code in isolation; you are building highly collaborative, service-oriented systems. The engineering organization at Navihealth places a strong emphasis on architectural reliability, scalability, and integration with complex clinical workflows.

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

Focus areas

  • Coding Interviews
  • Problem Solving
  • Technical Knowledge

The Navihealth interview process

Navihealth candidates report 6 rounds over 4-6 weeks. The stages below are what candidates describe, not a published process.

HR Screening Call

Discuss your background, career goals, and alignment with the company's mission.

What to demonstrate

  • Discuss your background, career goals, and alignment with the company's mission
  • Depth in Coding Interviews

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 Phone Screen

Initial technical assessment to evaluate core coding and problem-solving abilities.

What to demonstrate

  • Initial technical assessment to evaluate core coding and problem-solving abilities
  • Depth in Coding Interviews

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.

Final Interview Loop

Conducted in person or virtually, consisting of three to four rounds with multiple engineers.

What to demonstrate

  • Conducted in person or virtually, consisting of three to four rounds with multiple engineers
  • Depth in Coding Interviews

How to prepare

  • Answer aloud and timed: How would you design a clinical notification system that alerts care coordinators when a patient's status changes?
  • Answer aloud and timed: Walk me through how you would design a RESTful API for managing patient records, ensuring proper data validation and security.

Technical Discussions

Deep-dive technical discussions and whiteboarding exercises with engineers.

What to demonstrate

  • Deep-dive technical discussions and whiteboarding exercises with engineers
  • Depth in Coding Interviews

How to prepare

  • Answer aloud and timed: Describe how you would handle database schema migrations for a high-availability application without causing downtime.
  • Answer aloud and timed: How do you approach gathering requirements from non-technical stakeholders before you begin designing a new system component?

System Design Session

Evaluate system design capabilities through structured design sessions.

What to demonstrate

  • Evaluate system design capabilities through structured design sessions
  • Depth in Coding Interviews

How to prepare

  • Answer aloud and timed: Describe your experience working with Product Owners and QA Engineers during sprint planning and refinement.
  • Answer aloud and timed: How do you handle a situation where a Scrum Master identifies a bottleneck in your sprint deliverables?

Cross-Functional Round

Meet with team members like Product Owners and QA Engineers to assess Agile practices and collaboration.

What to demonstrate

  • Meet with team members like Product Owners and QA Engineers to assess Agile practices and collaboration
  • Depth in Coding Interviews

How to prepare

  • Answer aloud and timed: Walk me through how you ensure your code is ready for QA, and how you handle bug reports during a tight release cycle.
  • Answer aloud and timed: Explain your approach to handling technical debt while still meeting sprint commitments.

Where candidates lose points

Clarify requirements early

When presented with a design or coding problem, do not immediately start writing code. Ask clarifying questions to understand the constraints, inputs, and expected outputs. This demonstrates strong requirements-gathering skills, which Navihealth highly values.

Practice rapid-fire fundamentals

Be prepared for some interviewers to ask direct, fundamental computer science questions. Ensure you can explain concepts like OOP, database indexing, and memory management clearly and concisely.

Some technical interviewers may ask rapid-fire questions on CS fundamentals and expect quick, direct answers

If you do not know an answer immediately, state what you do know and walk through your logical reasoning rather than guessing silently.

Questions & practice

Implement a solution to find the first non-repeating character in a stream of data.

Medium · Coding & Problem Solving

Approach

  1. Restate the input: its shape, its size, and what is guaranteed about it.
  2. Name the brute-force solution and its complexity before improving on it.
  3. Choose the data structure from the access pattern, not from familiarity.
  4. State the target complexity and say which constraint rules the naive version out.

Follow-up

  • How does this change if the input no longer fits in memory?
  • What is the worst case, and how likely is it on real data?

Given an array of integers, write an algorithm to find all unique triplets that sum to a specific target value

Medium · Coding & Problem Solving

Given an array of integers, write an algorithm to find all unique triplets that sum to a specific target value.

Approach

  1. Restate the input: its shape, its size, and what is guaranteed about it.
  2. Name the brute-force solution and its complexity before improving on it.
  3. Choose the data structure from the access pattern, not from familiarity.
  4. State the target complexity and say which constraint rules the naive version out.

Follow-up

  • How does this change if the input no longer fits in memory?
  • What is the worst case, and how likely is it on real data?

Write a program to reverse a linked list, both iteratively and recursively, and compare their space complexiti

Medium · Coding & Problem Solving

Write a program to reverse a linked list, both iteratively and recursively, and compare their space complexities.

Approach

  1. Restate the input: its shape, its size, and what is guaranteed about it.
  2. Name the brute-force solution and its complexity before improving on it.
  3. Choose the data structure from the access pattern, not from familiarity.
  4. State the target complexity and say which constraint rules the naive version out.

Follow-up

  • How does this change if the input no longer fits in memory?
  • What is the worst case, and how likely is it on real data?

Given a set of overlapping intervals, write a function to merge them into a minimal set of non-overlapping int

Medium · Coding & Problem Solving

Given a set of overlapping intervals, write a function to merge them into a minimal set of non-overlapping intervals.

Approach

  1. Restate the input: its shape, its size, and what is guaranteed about it.
  2. Name the brute-force solution and its complexity before improving on it.
  3. Choose the data structure from the access pattern, not from familiarity.
  4. State the target complexity and say which constraint rules the naive version out.

Follow-up

  • How does this change if the input no longer fits in memory?
  • What is the worst case, and how likely is it on real data?

Explain the concept of garbage collection and how memory management works in your primary programming language

Medium · Core CS & Technical Fundamentals

Explain the concept of garbage collection and how memory management works in your primary programming language.

Approach

  1. Say what the runtime actually does before reasoning about the code.
  2. Name what is shared across threads and what owns each piece of state.
  3. Identify the window where an invariant is briefly untrue.
  4. Distinguish a value from a reference to it, and say which one you handed out.

Follow-up

  • What happens if two callers reach this at the same time?
  • Where could this allocate more than you expect?

Describe how you would handle database schema migrations for a high-availability application without causing d

Medium · Application Design & Architecture

Describe how you would handle database schema migrations for a high-availability application without causing downtime.

Approach

  1. Name the grain you start from and join outward from it.
  2. Check whether any join is one-to-many before aggregating, or the sums inflate.
  3. Say which index the query would use, and what makes it unusable.
  4. Handle the rows that do not match: that is usually the actual question.

Follow-up

  • How does the query change if that join becomes one-to-many?
  • What happens to this when the table is ten times larger?

Hold a per-tenant active cap against concurrent creates

Hard · write skew · isolation levels · constraints

A tenant on the standard plan may hold at most 50 resources with status='active'. The create handler runs SELECT count(*) FROM resource WHERE tenant_id = $1 AND status = 'active', compares to 50, then inserts. Two creates arrive 3 ms apart on different instances and the tenant lands at 51. Name the anomaly, say whether PostgreSQL 16 READ COMMITTED or REPEATABLE READ prevents it and why, then give an implementation that holds the cap at READ COMMITTED with the exact statements. Finally, say what changes when the cap is 'at most one running export per tenant' on job_run.

Approach

  1. Name it: write skew. The two transactions read an overlapping set and write disjoint rows, so there is no row-level conflict for the engine to detect and each commit is individually legal.
  2. Rule out the levels precisely. READ COMMITTED takes a fresh snapshot per statement and takes no lock on the counted rows, so both see 49. PostgreSQL's REPEATABLE READ is snapshot isolation: it removes non-repeatable reads and phantoms within the snapshot but still admits write skew, because the anomaly is not a re-read of a changed row, it is a read of a set that a concurrent transaction invalidates. Only SERIALIZABLE closes it, by tracking the read dependency and aborting one transaction with SQLSTATE 40001 — a guarantee that exists only if the application re-runs the whole transaction from the read.
  3. Convert the set predicate into a single-row conflict: keep tenant.active_resource_count and run UPDATE tenant SET active_resource_count = active_resource_count + 1 WHERE tenant_id = $1 AND active_resource_count < 50 in the same transaction as the INSERT. Zero affected rows is the cap, returned as 409. The row lock serialises the decision at any isolation level, and contention is bounded to one tenant's row — which is also the fair-scheduling unit, unlike a global counter that would convoy every tenant behind one row.
  4. State the cost you just took on: a counter is a second source of truth that can drift, so every path that changes status must adjust it inside the same transaction, and a periodic reconciliation has to exist, with resource_revision as the authority for what the count should have been.

Follow-up

  • A resource moves from archived back to active. Which statements change, and what breaks if the counter update and the status change land in different transactions?
  • The cap becomes plan-dependent and a plan can change mid-month. Where does the number 50 live, and who reads it?

How would you design a clinical notification system that alerts care coordinators when a patient's status chan

Medium · Application Design & Architecture

How would you design a clinical notification system that alerts care coordinators when a patient's status changes?

Approach

  1. Fix the scope first: who calls this, how often, and what they do when it fails.
  2. Name the read and write paths separately; they rarely have the same bottleneck.
  3. Choose a partition key and say what query it makes expensive.
  4. State the consistency you need, and where you are willing to be stale.

Follow-up

  • What breaks first when traffic grows ten times?
  • How does this behave when that dependency is down for an hour?

Walk me through how you would design a RESTful API for managing patient records, ensuring proper data validati

Medium · Application Design & Architecture

Walk me through how you would design a RESTful API for managing patient records, ensuring proper data validation and security.

Approach

  1. Fix the scope first: who calls this, how often, and what they do when it fails.
  2. Name the read and write paths separately; they rarely have the same bottleneck.
  3. Choose a partition key and say what query it makes expensive.
  4. State the consistency you need, and where you are willing to be stale.

Follow-up

  • What breaks first when traffic grows ten times?
  • How does this behave when that dependency is down for an hour?

How do you approach gathering requirements from non-technical stakeholders before you begin designing a new sy

Medium · Application Design & Architecture

How do you approach gathering requirements from non-technical stakeholders before you begin designing a new system component?

Approach

  1. Fix the scope first: who calls this, how often, and what they do when it fails.
  2. Name the read and write paths separately; they rarely have the same bottleneck.
  3. Choose a partition key and say what query it makes expensive.
  4. State the consistency you need, and where you are willing to be stale.

Follow-up

  • What breaks first when traffic grows ten times?
  • How does this behave when that dependency is down for an hour?

Walk me through how you ensure your code is ready for QA, and how you handle bug reports during a tight releas

Medium · Agile & Team Dynamics

Walk me through how you ensure your code is ready for QA, and how you handle bug reports during a tight release cycle.

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. 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 your approach to handling technical debt while still meeting sprint commitments.

Medium · Agile & Team Dynamics

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. 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 difference between optimistic and pessimistic locking in a relational database.

Medium · Core CS & Technical Fundamentals

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. 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 the primary differences between abstract classes and interfaces, and when would you use each?

Medium · Core CS & Technical Fundamentals

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. 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 does dependency injection improve the testability of an application?

Medium · Core CS & Technical Fundamentals

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. Work from the requirement backwards to the design.

Follow-up

  • What assumption would you test first?
  • How would you know your answer was wrong?

One customer endpoint stalls deliveries to every other destination

Medium · bulkhead · timeouts · saturation

The egress service delivers about 1.5k webhooks/second across 40,000 destinations, with a per-destination concurrency cap of 4 and a 10-second connect-plus-read timeout. Throughput falls to 300/second, queue depth climbs, and p99 delivery latency for unaffected destinations goes from 200 ms to minutes, while the error rate barely moves. One tenant holds 900 destination rows whose URLs share a hostname that now answers in 9.5 seconds. Explain the mechanism with the arithmetic, then give the containment in the order you would apply it.

Approach

  1. Look at saturation before errors. A flat error rate with collapsing throughput says nothing is failing, things are waiting, so the first signal to pull is in-flight request count or pool wait time rather than the error counter. This is the distinction that decides the whole investigation.
  2. Group in-flight work by resolved host, not by destination id. The cap is keyed per destination row, so 900 rows sharing one hostname buy 3,600 concurrent slots against a single host, each held for 9.5 seconds. The bulkhead was never a bulkhead for that host, and grouping by the wrong dimension is why the dashboard looked healthy.
  3. Do the arithmetic in both directions. Required concurrency is arrival rate times latency, so 1.5k/second at 200 ms needs about 300 in flight, which is entirely consumed by 3,600 slow slots; conversely whatever concurrency is left sustains rate equals concurrency divided by 9.5 seconds, which is the 300/second you are seeing. Matching both numbers is what promotes this from a plausible story to the mechanism.
  4. Explain why the circuit breaker never helped. It opens on consecutive failures, and a 9.5-second response inside a 10-second timeout is a success. Slow is not failing, so an error-rate breaker cannot see this; you need a slow-call ratio, a deadline propagated from the caller's remaining budget, or a concurrency limiter.

Follow-up

  • The host recovers to 80 ms. How long does the queue take to drain, and what does the drain do to the recovered host?
  • Where should the 10-second timeout number actually come from?

Suggested practice checklist

Built from the rounds and topics Navihealth candidates report.

Day 1 — Map the Navihealth loop

  • Write out the reported sequence: HR Screening Call, Technical Phone Screen, Final Interview Loop, Technical Discussions, System Design Session, Cross-Functional 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 6 reported rounds, with the weakest marked.

Day 2 — Work Coding Interviews

  • Spend the session on Coding Interviews, which Navihealth candidates report being tested on.
  • Write one worked example in Coding Interviews and time yourself on it.

Deliverable: One timed worked example in Coding Interviews.

Day 3 — Work Problem Solving

  • Spend the session on Problem Solving, which Navihealth 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.

Day 4 — Work Technical Knowledge

  • Spend the session on Technical Knowledge, which Navihealth candidates report being tested on.
  • Write one worked example in Technical Knowledge and time yourself on it.

Deliverable: One timed worked example in Technical Knowledge.

Day 5 — Answer out loud: Coding & Problem Solving

  • Answer aloud, timed: Implement a solution to find the first non-repeating character in a stream of data.
  • Answer aloud, timed: Given an array of integers, write an algorithm to find all unique triplets that sum to a specific target value.

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

Day 6 — Answer out loud: Application Design & Architecture

  • Answer aloud, timed: How would you design a clinical notification system that alerts care coordinators when a patient's status changes?
  • Answer aloud, timed: Walk me through how you would design a RESTful API for managing patient records, ensuring proper data validation and security.

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

Day 7 — Answer out loud: Agile & Team Dynamics

  • Answer aloud, timed: Describe your experience working with Product Owners and QA Engineers during sprint planning and refinement.
  • Answer aloud, timed: How do you handle a situation where a Scrum Master identifies a bottleneck in your sprint deliverables?

Deliverable: Spoken answers to 2 reported Agile & Team Dynamics question(s), under time.

Behavioural preparation

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

Describe your experience working with Product Owners and QA Engineers during sprint planning and refinement.

Medium · Agile & Team Dynamics

Approach

  1. Pick a story where you made the decision, not one where you watched it.
  2. State the situation in two sentences and spend the rest on the reasoning.
  3. Give the blast radius: what could have broken, and what you measured.
  4. Name the disagreement and how you resolved it with evidence.

Follow-up

  • What would you do differently if you ran that again?
  • How did you know your change caused the improvement?

How do you handle a situation where a Scrum Master identifies a bottleneck in your sprint deliverables?

Medium · Agile & Team Dynamics

Approach

  1. Pick a story where you made the decision, not one where you watched it.
  2. State the situation in two sentences and spend the rest on the reasoning.
  3. Give the blast radius: what could have broken, and what you measured.
  4. Name the disagreement and how you resolved it with evidence.

Follow-up

  • What would you do differently if you ran that again?
  • How did you know your change caused the improvement?

Turn a code review disagreement into a decision

Easy · code review · optimistic concurrency · communication

A colleague's change updates a row with UPDATE resource SET version = version + 1 WHERE resource_id = $1 AND version = $2 and treats an affected-row count of zero as a successful no-op. You read that as a silently lost update; they think returning 200 is friendlier to clients than returning a conflict. Describe how you have handled a review disagreement of this shape: what goes in the comment, when you leave the thread, and who decides. Then write the comment you would leave here, in under 80 words.

Approach

  1. Sort the disagreement before writing anything. A silently discarded write is a correctness claim about data; the choice between 409 and 412 is taste. Only the first justifies blocking a merge, and saying which one you are doing is most of the value of the comment.
  2. Make the claim reproducible in the comment itself with an interleaving rather than a principle: A reads version 7, B reads version 7, B commits version 8, A's predicate matches zero rows, A is told it succeeded and A's edit is gone.
  3. Offer the alternative with its cost attached: return 409 carrying the current version and the revision that won, so the client can re-read and re-apply. Note that automatic retry is not the fix, because a retry re-reads the winner's state and reapplies an intent formed against data that no longer exists.
  4. Apply an escalation rule you can state: two round trips on the thread, then a call, and the service's owner decides rather than the reviewer. A reviewer who cannot be overruled is a bottleneck with extra steps.

Follow-up

  • Where would you put the test that fails if someone reintroduces the swallowed zero rowcount?
  • The author says clients cannot handle a 409. How do you check whether that is true?