cswork / libraryOpen practice workspace

Interview guides · NAVA TECH

NAVA TECH Software Engineer Interview Guide

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

The 60-second brief

As a Software Engineer at NAVA TECH, you play a vital role in architecting, developing, and deploying robust digital solutions that drive business transformation. NAVA TECH operates as a premier technology partner, meaning our engineers work on highly visible projects that directly impact major corporate clients as well as our own internal digital platforms. You will be responsible for building scalable, high-performance software systems that solve complex real-world problems. This position demands a unique blend of technical excellence and collaborative agility. You will not just write clean, maintainable code; you will also influence system architecture, optimize database performances, and design intuitive user interfaces.

This guide is scoped to a Software Engineer candidate at NAVA TECH.

Focus areas

  • System Design
  • Coding Interviews / Live Coding
  • Technical Interviewing

The NAVA TECH interview process

NAVA TECH candidates report 3 rounds over 3-5 weeks. The stages below are what candidates describe, not a published process.

Initial Screening Call

A call from the recruitment team to understand your career aspirations, past experiences, and general fit.

What to demonstrate

  • A call from the recruitment team to understand your career aspirations, past experiences, and general fit
  • Depth in System Design

How to prepare

  • Be able to walk your CV end to end in two minutes, and say why this company specifically.
  • Have your salary expectations, notice period and location constraints ready, and ask for the rest of the loop in writing.

Technical Evaluations

A series of assessments including hands-on coding, system design discussions, and conversations with engineering leadership.

What to demonstrate

  • A series of assessments including hands-on coding, system design discussions, and conversations with engineering leadership
  • Depth in System Design

How to prepare

  • Answer aloud and timed: What is Atomic Design, and how do you apply its principles to build highly reusable UI components?
  • Answer aloud and timed: How do you manage global state in a complex web application, and what are the trade-offs of your chosen approach?

Final Collaborative Session

A session to ensure alignment with project-specific demands, depending on the team or client project.

What to demonstrate

  • A session to ensure alignment with project-specific demands, depending on the team or client project
  • Depth in System Design

How to prepare

  • Answer aloud and timed: Walk me through your approach to executing a large-scale database migration with zero downtime.
  • Answer aloud and timed: How do you design an API gateway to handle high traffic spikes while ensuring secure authentication and rate limiting?

Where candidates lose points

Communicate your thought process

Do not code in silence. Talk through your assumptions, explain why you are choosing a specific data structure, and discuss alternative solutions before writing a single line of code.

Focus on the business context

When describing your past projects, do not just explain what you built. Explain why you built it, the business problem it solved, and the measurable impact it had on the organization.

Be ready for database migration discussions

Candidates frequently encounter questions regarding database structure, schema changes, and data integrity. Review standard migration patterns before your interview.

Ask thoughtful questions

At the end of each round, use the opportunity to ask your interviewers about their current technical challenges, team culture, and engineering practices. This demonstrates genuine curiosity and engagement.

Questions & practice

Given an array of integers, write an efficient algorithm to find the two numbers that add up to a specific tar

Medium · Coding & Algorithmic Problem Solving

Given an array of integers, write an efficient algorithm to find the two numbers that add up to a specific target.

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?

How would you implement a function to deeply clone an object in JavaScript, handling circular references?

Medium · Coding & Algorithmic Problem Solving

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?

Write a program to merge two sorted linked lists and analyze its time and space complexity.

Medium · Coding & Algorithmic 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?

Explain why the owner filter ignores the listing index

Medium · composite index · query plans · sort elimination

The only index on resource is (tenant_id, status, updated_at DESC, resource_id DESC). A new endpoint returns one user's resources across all statuses, newest created first: WHERE tenant_id = $1 AND owner_user_id = $2 ORDER BY created_at DESC LIMIT 20. On a tenant with 2M rows it takes 900 ms and EXPLAIN shows a sort above a large scan. Explain precisely why the existing index cannot serve it, give the index that can, and state which of these the new index still will not help: owner_user_id alone across tenants; the same query ordered by updated_at. PostgreSQL 16.

Approach

  1. Separate the two jobs an index does. For filtering, a composite btree is seekable only on a left prefix, so with no predicate on status the scan can at best range over tenant_id and test owner_user_id per row; PostgreSQL 16 has no btree skip scan to jump the unconstrained column.
  2. For ordering, the index is sorted by (status, updated_at) within a tenant and not by created_at, so the LIMIT cannot stop early: every matching row is read and then sorted. That is the 'Sort Method: top-N heapsort' line, and it is why the plan reads 2M rows to answer with 20.
  3. Derive the replacement from the access path — equality, equality, then the ordering column: CREATE INDEX CONCURRENTLY ON resource (tenant_id, owner_user_id, created_at DESC). The scan seeks to the (tenant, owner) range and walks 20 entries in order, so the Sort node disappears along with the row-read.
  4. Treat INCLUDE (title, status) as conditional, not free. An index-only scan still visits the heap for any row whose page is not marked all-visible, so on a table taking 1.2k writes/second the win depends on autovacuum keeping the visibility map current, and the wider index costs more on every insert.

Follow-up

  • 90% of rows are status='active'. Would a partial index WHERE status = 'active' change your answer, and for which of the three queries?
  • A dashboard runs this for 40 owners in one page load. What changes about the design?

Keep soft-deleted accounts from blocking re-registration

Easy · soft delete · unique constraints · engine differences

app_user holds user_id, tenant_id, email CITEXT, password_hash (NULL for SSO principals), email_verified_at, auth_version, status ('invited','active','suspended','deactivated'), created_at, updated_at, deleted_at. Two live accounts for one address inside a tenant must be impossible, but an address freed by a soft delete must be reusable, and the same tenant may delete and re-register it repeatedly. Write the uniqueness DDL for PostgreSQL 16, then the equivalent for MySQL 8 where partial indexes do not exist, and say what each permits once three deleted rows already hold that address.

Approach

  1. Start from what is actually unique: not (tenant_id, email), but (tenant_id, email) among live rows. PostgreSQL says that directly — CREATE UNIQUE INDEX app_user_live_email ON app_user (tenant_id, email) WHERE deleted_at IS NULL. A full constraint over the same two columns burns the address permanently the first time someone deletes an account.
  2. Keep case-insensitivity in the type or the index, never in the application: CITEXT as given, or UNIQUE (tenant_id, lower(email)) as an expression index where the extension is unavailable. A case-sensitive unique column is exactly how two accounts for one human appear.
  3. For MySQL 8 the predicate has to move inside the key: add a discriminator column that is a constant 0 while the row is live and is set to user_id on delete, with UNIQUE (tenant_id, email, deleted_marker). Live rows share the constant and still collide; deleted rows differ from each other and stop colliding.
  4. State the NULL variant and its dependency: leaving the marker NULL for deleted rows also works, because a unique index treats NULLs as distinct — true in MySQL, and true in PostgreSQL only under the default NULLS DISTINCT, which PostgreSQL 15 lets you reverse. Check the polarity against the three existing deleted rows: constant-on-live is what preserves the collision you want, and reversing it silently admits duplicate live accounts.

Follow-up

  • A deleted account re-registers with the same address the next day. Do the old resource rows follow the new user_id, and how does the API keep the two principals apart?
  • How do you honour an erasure request while resource_revision.actor_user_id still references this table?

How do you structure a front-end project to ensure long-term maintainability and scalability?

Medium · Front-End & Component Architecture

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?

Explain the lifecycle of React hooks and how you optimize functional components to prevent unnecessary re-rend

Medium · Front-End & Component Architecture

Explain the lifecycle of React hooks and how you optimize functional components to prevent unnecessary re-renders.

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?

What is Atomic Design, and how do you apply its principles to build highly reusable UI components?

Medium · Front-End & Component Architecture

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 manage global state in a complex web application, and what are the trade-offs of your chosen approa

Medium · Front-End & Component Architecture

How do you manage global state in a complex web application, and what are the trade-offs of your chosen approach?

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 your approach to executing a large-scale database migration with zero downtime.

Medium · System Design & Infrastructure

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 design an API gateway to handle high traffic spikes while ensuring secure authentication and rate l

Medium · System Design & Infrastructure

How do you design an API gateway to handle high traffic spikes while ensuring secure authentication and rate limiting?

Approach

  1. Say who the caller is and what they do when the call fails halfway.
  2. Define the identity of a request so a retry cannot double-apply it.
  3. Separate accepted, pending, failed and confirmed; they are different facts.
  4. 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?

How do you determine when to use a relational database versus a non-relational database for a new microservice

Medium · System Design & Infrastructure

How do you determine when to use a relational database versus a non-relational database for a new microservice?

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?

Describe a scenario where you had to debug a severe performance bottleneck in a distributed system.

Medium · System Design & Infrastructure

Approach

  1. Establish what changed and when, before forming any theory.
  2. Pick a bisection that eliminates candidates whichever way it turns out.
  3. Check the instrumentation before believing the symptom.
  4. 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?

Suggested practice checklist

Built from the rounds and topics NAVA TECH candidates report.

Day 1 — Map the NAVA TECH loop

  • Write out the reported sequence: Initial Screening Call, Technical Evaluations, Final Collaborative Session.
  • 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.

Day 2 — Work System Design

  • Spend the session on System Design, which NAVA TECH candidates report being tested on.
  • Write one worked example in System Design and time yourself on it.

Deliverable: One timed worked example in System Design.

Day 3 — Work Coding Interviews / Live Coding

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

Deliverable: One timed worked example in Coding Interviews / Live Coding.

Day 4 — Work Technical Interviewing

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

Deliverable: One timed worked example in Technical Interviewing.

Day 5 — Answer out loud: Front-End & Component Architecture

  • Answer aloud, timed: How do you structure a front-end project to ensure long-term maintainability and scalability?
  • Answer aloud, timed: Explain the lifecycle of React hooks and how you optimize functional components to prevent unnecessary re-renders.

Deliverable: Spoken answers to 2 reported Front-End & Component Architecture question(s), under time.

Day 6 — Answer out loud: System Design & Infrastructure

  • Answer aloud, timed: Walk me through your approach to executing a large-scale database migration with zero downtime.
  • Answer aloud, timed: How do you design an API gateway to handle high traffic spikes while ensuring secure authentication and rate limiting?

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

Day 7 — Answer out loud: Coding & Algorithmic Problem Solving

  • Answer aloud, timed: Given an array of integers, write an efficient algorithm to find the two numbers that add up to a specific target.
  • Answer aloud, timed: How would you implement a function to deeply clone an object in JavaScript, handling circular references?

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

Behavioural preparation

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

How do you handle asynchronous operations in your code, and how do you manage error propagation across multipl

Medium · Coding & Algorithmic Problem Solving

How do you handle asynchronous operations in your code, and how do you manage error propagation across multiple parallel promises?

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?

Describe a time when you had to work with a highly ambiguous technical requirement. How did you align with sta

Medium · Behavioral & Professional Experience

Describe a time when you had to work with a highly ambiguous technical requirement. How did you align with stakeholders?

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?

Tell me about a past project where you had to compromise on technical debt to meet a tight business deadline.

Medium · Behavioral & Professional Experience

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 peer disagrees with your architectural proposal during a design review?

Medium · Behavioral & Professional Experience

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?

Share an experience where you had to quickly learn and adopt a completely new technology stack for a critical

Medium · Behavioral & Professional Experience

Share an experience where you had to quickly learn and adopt a completely new technology stack for a critical project.

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?