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Full Visibility Software Engineer Interview Guide

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

The 60-second brief

As a Software Engineer at Full Visibility, you play a vital role in delivering innovative technical solutions that address the nation's most critical and sensitive missions. Operating at the intersection of digital transformation, artificial intelligence, analytics, and cloud engineering, you build and manage application development projects that directly support federal, defense, and law enforcement agencies. Your work directly enables large-scale data processing, computationally intensive statistical modeling, and advanced analytics for high-stakes environments. This position is critical because it drives the programmatic integration of third-party components, introduces custom capabilities, and automates core IT infrastructure operations. You will participate in all aspects of the software development lifecycle, from planning and architecture to testing and deployment.

This guide is scoped to a Software Engineer candidate at Full Visibility.

Focus areas

  • Java
  • Python
  • AWS

The Full Visibility interview process

Full Visibility candidates report 2 rounds over 2-4 weeks. The stages below are what candidates describe, not a published process.

Phone Screening

Initial call with a recruiter to discuss your background, career goals, and security clearance status.

What to demonstrate

  • Initial call with a recruiter to discuss your background, career goals, and security clearance status
  • Depth in Java

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 Evaluation

Structured assessments to evaluate your practical development skills and architectural thinking.

What to demonstrate

  • Structured assessments to evaluate your practical development skills and architectural thinking
  • Depth in Java

How to prepare

  • Answer aloud and timed: Describe a time when you had to optimize a slow-running query or routine. What steps did you take?
  • Answer aloud and timed: Walk through your thought process when designing a modular software component from scratch.

Where candidates lose points

Review your personal code repositories

Interviewers frequently appreciate discussing real code samples you have written, so be prepared to walk through your design choices, trade-offs, and lessons learned from past personal or professional projects.

Focus on fundamentals over trivia

Rather than memorizing framework minutiae, concentrate your preparation on solid software engineering principles, object-oriented design in Java, and cloud architecture fundamentals.

Communicate your thought process

When presented with a technical or problem-solving scenario, always talk through your logic out loud so the interviewer can follow your analytical reasoning.

Highlight mission alignment

Emphasize your appreciation for national security and law enforcement missions, connecting your technical work to the real-world impact it delivers for federal clients.

Leverage the full employee mindset

Reflect the company's core values of collaboration, continuous development, and mutual support in your behavioral answers.

Questions & practice

Questions in this category focus on testing your core developer aptitude, analytical thinking, and logical app

Medium · General Aptitude and Problem Solving

Questions in this category focus on testing your core developer aptitude, analytical thinking, and logical approach rather than hyper-specific tool trivia.

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?

Walk through your thought process when designing a modular software component from scratch.

Medium · General Aptitude and 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?

How do you ensure thread safety in concurrent Java applications?

Medium · Java and Microservices Development

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?

Find version gaps and relay lag with window functions

Medium · window functions · event tables · frame semantics

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

  1. 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.
  2. 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.
  3. 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.
  4. 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?

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?

These questions evaluate your proficiency in backend development, object-oriented principles, and modern micro

Medium · Java and Microservices Development

These questions evaluate your proficiency in backend development, object-oriented principles, and modern microservices architectures.

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 how you manage state and communication across distributed microservices.

Medium · Java and Microservices Development

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 are the key benefits and potential pitfalls of using dependency injection in Java applications?

Medium · Java and Microservices Development

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?

This category covers cloud infrastructure, AWS ecosystem familiarity, and end-to-end application development c

Medium · Cloud and Full Stack Engineering

This category covers cloud infrastructure, AWS ecosystem familiarity, and end-to-end application development capabilities.

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 key factors do you consider when deploying a scalable application architecture on AWS?

Medium · Cloud and Full Stack Engineering

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 securing data both at rest and in transit within cloud environments?

Medium · Cloud and Full Stack Engineering

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 automate deployment pipelines to ensure consistent releases?

Medium · Cloud and Full Stack Engineering

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 do you approach debugging a complex issue in a distributed application with limited logs?

Medium · General Aptitude and Problem Solving

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 Full Visibility candidates report.

Day 1 — Map the Full Visibility loop

  • Write out the reported sequence: Phone Screening, Technical Evaluation.
  • 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 2 reported rounds, with the weakest marked.

Day 2 — Work Java

  • Spend the session on Java, which Full Visibility candidates report being tested on.
  • Write one worked example in Java and time yourself on it.

Deliverable: One timed worked example in Java.

Day 3 — Work Python

  • Spend the session on Python, which Full Visibility candidates report being tested on.
  • Write one worked example in Python and time yourself on it.

Deliverable: One timed worked example in Python.

Day 4 — Work AWS

  • Spend the session on AWS, which Full Visibility candidates report being tested on.
  • Write one worked example in AWS and time yourself on it.

Deliverable: One timed worked example in AWS.

Day 5 — Answer out loud: General Aptitude and Problem Solving

  • Answer aloud, timed: Questions in this category focus on testing your core developer aptitude, analytical thinking, and logical approach rather than hyper-specific tool trivia.
  • Answer aloud, timed: How do you approach debugging a complex issue in a distributed application with limited logs?

Deliverable: Spoken answers to 2 reported General Aptitude and Problem Solving question(s), under time.

Day 6 — Answer out loud: Java and Microservices Development

  • Answer aloud, timed: These questions evaluate your proficiency in backend development, object-oriented principles, and modern microservices architectures.
  • Answer aloud, timed: Explain how you manage state and communication across distributed microservices.

Deliverable: Spoken answers to 2 reported Java and Microservices Development question(s), under time.

Day 7 — Answer out loud: Cloud and Full Stack Engineering

  • Answer aloud, timed: This category covers cloud infrastructure, AWS ecosystem familiarity, and end-to-end application development capabilities.
  • Answer aloud, timed: What key factors do you consider when deploying a scalable application architecture on AWS?

Deliverable: Spoken answers to 2 reported Cloud and Full Stack Engineering question(s), under time.

Behavioural preparation

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

Describe a time when you had to optimize a slow-running query or routine. What steps did you take?

Medium · General Aptitude and Problem Solving

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 conflicting technical requirements from different stakeholders during a project?

Medium · General Aptitude and Problem Solving

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?

Discuss your experience with integrating RESTful APIs and managing third-party component dependencies.

Medium · Java and Microservices Development

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 your experience building full stack applications using modern frontend frameworks and backend service

Medium · Cloud and Full Stack Engineering

Describe your experience building full stack applications using modern frontend frameworks and backend services.

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?

These conversational queries assess your background, code quality philosophy, and how you collaborate within t

Medium · Behavioral and Experience Discussion

These conversational queries assess your background, code quality philosophy, and how you collaborate within technical teams.

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?

Can you discuss some personal code samples from your repository and explain your design choices?

Medium · Behavioral and Experience Discussion

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 stay updated with emerging software engineering trends and security practices?

Medium · Behavioral and Experience Discussion

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 situation where a project timeline shifted unexpectedly and how you adjusted your deliverables.

Medium · Behavioral and Experience Discussion

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?

What interests you about supporting federal missions and working within cleared environments?

Medium · Behavioral and Experience Discussion

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?