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Gecko Robotics Software Engineer Interview Guide

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

The 60-second brief

At Gecko Robotics, a Software Engineer is at the forefront of modernizing critical infrastructure. You are not just writing code; you are building the digital backbone that interprets data from wall-climbing robots and industrial sensors. Your work directly impacts the safety and reliability of power plants, manufacturing facilities, and other essential systems that keep society running. This role is uniquely challenging because it sits at the intersection of hardware and high-level software. You will navigate the complexity of time-series IoT data, document intelligence, and agentic AI systems. Because Gecko Robotics operates in an office-first, high-collaboration environment, you will work closely with cross-functional teams to solve real-world problems.

This guide is scoped to a Software Engineer candidate at Gecko Robotics.

Focus areas

  • Data Structures & Algorithms (DSA)
  • System Design
  • Dynamic Programming (DP)

The Gecko Robotics interview process

Gecko Robotics candidates report 5 rounds over 4-6 weeks. The stages below are what candidates describe, not a published process.

Technical Screening

Initial assessment to evaluate technical aptitude and coding skills.

What to demonstrate

  • Initial assessment to evaluate technical aptitude and coding skills
  • Depth in Data Structures & Algorithms (DSA)

How to prepare

  • Answer aloud and timed: How would you implement a localization scan of a room?
  • Answer aloud and timed: Explain the basics of IMU (Inertial Measurement Unit) sensors and their application.

Algorithmic Challenges

Candidates will solve coding challenges that test their algorithmic skills.

What to demonstrate

  • Candidates will solve coding challenges that test their algorithmic skills
  • Depth in Data Structures & Algorithms (DSA)

How to prepare

  • Answer aloud and timed: What are the primary considerations when processing high-volume time-series IoT data?
  • Answer aloud and timed: How do you handle distributed systems and data consistency in a production environment?

System Design Discussion

In-depth conversation about system design principles and past experiences.

What to demonstrate

  • In-depth conversation about system design principles and past experiences
  • Depth in Data Structures & Algorithms (DSA)

How to prepare

  • Answer aloud and timed: Can you explain the trade-offs between different NoSQL databases for storing sensor logs?
  • Answer aloud and timed: Solve a problem involving binary search implementation.

Behavioral Interview

Discussion focused on past project experiences and alignment with company mission.

What to demonstrate

  • Discussion focused on past project experiences and alignment with company mission
  • Depth in Data Structures & Algorithms (DSA)

How to prepare

  • Prepare three examples from your own work, each with a decision you made and an outcome you can quantify.
  • Re-read the description of the behavioral interview above and write down what you would ask to confirm before it.

Onsite or Virtual-Onsite

Final stage involving comprehensive evaluations in a face-to-face or virtual setting.

What to demonstrate

  • Final stage involving comprehensive evaluations in a face-to-face or virtual setting
  • Depth in Data Structures & Algorithms (DSA)

How to prepare

  • Answer aloud and timed: Explain your approach to debugging a production system with limited logs.
  • Answer aloud and timed: Why are you interested in the mission of Gecko Robotics?

Where candidates lose points

Own your answers

When explaining your past projects, be prepared to answer deep-dive questions about why you chose specific libraries or architectures.

Ask clarifying questions

In coding and system design rounds, never start coding immediately. Clarify constraints and requirements first.

Focus on the mission

Show that you understand the impact of your work on infrastructure reliability; this alignment is highly valued.

Be prepared for ambiguity

Some interviewers may intentionally present open-ended problems to see how you structure your thinking.

Practice your "Why

Have a clear, compelling reason for why you want to work at Gecko Robotics specifically, beyond just the technical challenge.

Questions & practice

Solve a problem involving binary search implementation.

Medium · Coding and Algorithms

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 an algorithm to process a complex dataset with specific time and space constraints.

Medium · Coding and Algorithms

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?

Implement a solution for a data structure manipulation problem (e.g., dynamic programming or graph traversal).

Medium · Coding and Algorithms

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 approach working in an ambiguous, early-stage environment?

Medium · Behavioral and Leadership

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?

Denormalise tenant onto revisions and backfill it live

Hard · denormalisation · online migration · backfill

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

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

Write the update path that detects a concurrent edit

Medium · optimistic concurrency · transactional outbox · audit history

resource carries version INT NOT NULL DEFAULT 1. resource_revision holds revision_id, resource_id, version, actor_user_id, change_kind, patch JSONB, request_id, created_at with UNIQUE (resource_id, version). outbox_event holds aggregate_type, aggregate_id, aggregate_version, event_type, payload, status. A PUT carries the version the client read. Write the exact statements for the single transaction that applies the edit, records the revision and enqueues 'resource.updated', and give the handler's branch on zero affected rows. Then say what PostgreSQL 16 does under READ COMMITTED when two of these updates hit one row at once.

Approach

  1. One transaction, three writes, no network call inside it: UPDATE resource SET title = $3, version = version + 1, updated_at = now() WHERE resource_id = $1 AND tenant_id = $4 AND version = $2; then INSERT the resource_revision row at version $2 + 1; then INSERT the outbox_event row at the same aggregate_version. The event goes to a table rather than a broker because no transaction spans both.
  2. Branch on the affected-row count before doing anything else. Zero has three causes — stale version, wrong tenant, row gone — so re-read once and map to 409 carrying the current version, or 404 for an id outside the caller's tenant, which also stops the endpoint confirming that another tenant's id exists.
  3. State the engine behaviour instead of assuming it. Under READ COMMITTED the second UPDATE blocks on the row lock, and when the first commits PostgreSQL re-evaluates the WHERE clause against the newly committed row, so the version predicate now fails and the statement reports zero rows. Under REPEATABLE READ the identical collision raises SQLSTATE 40001 instead, so the handler must fold both shapes into one conflict response.
  4. Keep UNIQUE (resource_id, version) even though the predicate already serialises writers. It is what makes a lost update unwritable if any other path ever reaches the revision table, and it converts a logic bug into 23505 rather than into a silently missing history row.

Follow-up

  • A client sends the version it read ten minutes ago and the resource has moved three versions. What is in your 409 so it can resolve the conflict without a full re-fetch?
  • Two editors, two disjoint fields, no overlap. Does your answer still refuse the second write, and should it?

How would you implement a localization scan of a room?

Medium · Technical and Domain Knowledge

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 basics of IMU (Inertial Measurement Unit) sensors and their application.

Medium · Technical and Domain Knowledge

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 considerations when processing high-volume time-series IoT data?

Medium · Technical and Domain Knowledge

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?

Can you explain the trade-offs between different NoSQL databases for storing sensor logs?

Medium · Technical and Domain Knowledge

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 debugging a production system with limited logs.

Medium · Coding and Algorithms

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 Gecko Robotics candidates report.

Day 1 — Map the Gecko Robotics loop

  • Write out the reported sequence: Technical Screening, Algorithmic Challenges, System Design Discussion, Behavioral Interview, Onsite or Virtual-Onsite.
  • For each round, write one sentence on what it is judging, from the description above, and mark the one you are least ready for.

Deliverable: A one-page map of the 5 reported rounds, with the weakest marked.

Day 2 — Work Data Structures & Algorithms (DSA)

  • Spend the session on Data Structures & Algorithms (DSA), which Gecko Robotics candidates report being tested on.
  • Write one worked example in Data Structures & Algorithms (DSA) and time yourself on it.

Deliverable: One timed worked example in Data Structures & Algorithms (DSA).

Day 3 — Work System Design

  • Spend the session on System Design, which Gecko Robotics 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 4 — Work Dynamic Programming (DP)

  • Spend the session on Dynamic Programming (DP), which Gecko Robotics candidates report being tested on.
  • Write one worked example in Dynamic Programming (DP) and time yourself on it.

Deliverable: One timed worked example in Dynamic Programming (DP).

Day 5 — Answer out loud: Technical and Domain Knowledge

  • Answer aloud, timed: How would you implement a localization scan of a room?
  • Answer aloud, timed: Explain the basics of IMU (Inertial Measurement Unit) sensors and their application.

Deliverable: Spoken answers to 2 reported Technical and Domain Knowledge question(s), under time.

Day 6 — Answer out loud: Coding and Algorithms

  • Answer aloud, timed: Solve a problem involving binary search implementation.
  • Answer aloud, timed: Write an algorithm to process a complex dataset with specific time and space constraints.

Deliverable: Spoken answers to 2 reported Coding and Algorithms question(s), under time.

Day 7 — Answer out loud: Behavioral and Leadership

  • Answer aloud, timed: Why are you interested in the mission of Gecko Robotics?
  • Answer aloud, timed: Tell me about a time you owned a technical problem from end to end.

Deliverable: Spoken answers to 2 reported Behavioral and Leadership question(s), under time.

Behavioural preparation

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

How do you handle distributed systems and data consistency in a production environment?

Medium · Technical and Domain Knowledge

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?

Why are you interested in the mission of Gecko Robotics?

Medium · Behavioral and Leadership

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 time you owned a technical problem from end to end.

Medium · Behavioral and Leadership

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 you had to manage conflicting requirements from different stakeholders.

Medium · Behavioral and Leadership

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 that you are particularly proud of and why.

Medium · Behavioral and Leadership

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?