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1X Technologies AS Software Engineer Interview Guide

1X Technologies AS Software Engineer interview guide: reported rounds, questions and how candidates describe the process.

The 60-second brief

A Software Engineer at 1X Technologies AS works at the absolute frontier of physical artificial intelligence. The mission here is not just to build software, but to create the digital mind, nervous system, and infrastructure that power next-generation humanoid robots like Eve and Neo. Engineers in this role build the foundational layers that enable safe, intelligent, and natural human-robot interaction in real-world environments. Because 1X Technologies AS integrates hardware, low-level control, simulation, and cloud infrastructure, your work as a software engineer directly impacts how robots perceive, navigate, and manipulate their surroundings.

This guide is scoped to a Software Engineer candidate at 1X Technologies AS.

Focus areas

  • Cloud and infrastructure engineering
  • Production software engineering
  • Systems engineering

The 1X Technologies AS interview process

1X Technologies AS candidates report 3 rounds over 3-5 weeks. The stages below are what candidates describe, not a published process.

Recruiter Screen

Initial screening call with a recruiter or HR representative to evaluate fit and technical capabilities.

What to demonstrate

  • Initial screening call with a recruiter or HR representative to evaluate fit and technical capabilities
  • Depth in Cloud and infrastructure engineering

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 Screening Call

A technical screening call with the hiring manager to assess your technical skills.

What to demonstrate

  • A technical screening call with the hiring manager to assess your technical skills
  • Depth in Cloud and infrastructure engineering

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 Panel Interview

Comprehensive technical panel or on-site interview with multiple engineers covering specialized topics.

What to demonstrate

  • Comprehensive technical panel or on-site interview with multiple engineers covering specialized topics
  • Depth in Cloud and infrastructure engineering

How to prepare

  • Answer aloud and timed: What are the primary performance bottlenecks when transmitting high-frequency sensor data over a local network?
  • Answer aloud and timed: How do you handle latency and packet loss in a real-time teleoperation loop?

Where candidates lose points

Provide Detailed, Thorough Answers

Whether in a live interview or a recorded session, avoid brief or superficial answers. The team values engineering depth; walk through your reasoning, discuss trade-offs, and explain the "why" behind your technical decisions.

Master Your Fundamentals

Don't get bogged down trying to memorize complex robotics algorithms. Focus on mastering core computer science and engineering fundamentals—concurrency, memory management, basic physics, and systems design—as these form the foundation of all technical evaluations.

Be proactive in your communication and follow up professionally if you experience delays in the interview process

With teams operating across multiple time zones and locations (including Norway, the US, and Taiwan), communication gaps can occasionally occur during busy hiring cycles.

Questions & practice

Explain the difference between process-level and thread-level concurrency in a Linux environment.

Medium · Systems & Low-Level Programming

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?

How would you debug a race condition in a multi-threaded system controlling physical actuators?

Medium · Systems & Low-Level Programming

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 a real-time operating system (RTOS) handles task scheduling compared to standard Linux.

Medium · Systems & Low-Level Programming

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?

What are the primary performance bottlenecks when transmitting high-frequency sensor data over a local network

Medium · Systems & Low-Level Programming

What are the primary performance bottlenecks when transmitting high-frequency sensor data over a local network?

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?

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?

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?

Describe the architecture of a physics engine used for high-fidelity robot simulation.

Medium · Robotics, Simulation, and Teleoperation

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 would you synchronize a robot's physical state with its digital twin in real-time?

Medium · Robotics, Simulation, and Teleoperation

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 approach would you take to calibrate a multi-camera vision system on a mobile robot?

Medium · Robotics, Simulation, and Teleoperation

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 how you would implement joint-space control versus Cartesian-space control for a robotic arm.

Medium · Robotics, Simulation, and Teleoperation

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 use CAD tools to verify physical clearances and component fitment in a robotic assembly?

Medium · Hardware, CAD, and Diagnostics

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?

Describe your process for diagnosing a communication failure on a CAN bus.

Medium · Hardware, CAD, and Diagnostics

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 factors influence the selection of sensors for monitoring joint temperature and motor health?

Medium · Hardware, CAD, and Diagnostics

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 write software to validate the structural integrity or material limits of a physical prototype?

Medium · Hardware, CAD, and Diagnostics

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 how you would design an automated diagnostic suite for a robot's electrical subsystem.

Medium · Hardware, CAD, and Diagnostics

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 memory allocation in a real-time system to avoid latency spikes?

Medium · Systems & Low-Level Programming

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 1X Technologies AS candidates report.

Day 1 — Map the 1X Technologies AS loop

  • Write out the reported sequence: Recruiter Screen, Technical Screening Call, Technical Panel Interview.
  • 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 Cloud and infrastructure engineering

  • Spend the session on Cloud and infrastructure engineering, which 1X Technologies AS candidates report being tested on.
  • Write one worked example in Cloud and infrastructure engineering and time yourself on it.

Deliverable: One timed worked example in Cloud and infrastructure engineering.

Day 3 — Work Production software engineering

  • Spend the session on Production software engineering, which 1X Technologies AS candidates report being tested on.
  • Write one worked example in Production software engineering and time yourself on it.

Deliverable: One timed worked example in Production software engineering.

Day 4 — Work Systems engineering

  • Spend the session on Systems engineering, which 1X Technologies AS candidates report being tested on.
  • Write one worked example in Systems engineering and time yourself on it.

Deliverable: One timed worked example in Systems engineering.

Day 5 — Answer out loud: Systems & Low-Level Programming

  • Answer aloud, timed: How do you manage memory allocation in a real-time system to avoid latency spikes?
  • Answer aloud, timed: Explain the difference between process-level and thread-level concurrency in a Linux environment.

Deliverable: Spoken answers to 2 reported Systems & Low-Level Programming question(s), under time.

Day 6 — Answer out loud: Robotics, Simulation, and Teleoperation

  • Answer aloud, timed: How do you handle latency and packet loss in a real-time teleoperation loop?
  • Answer aloud, timed: Describe the architecture of a physics engine used for high-fidelity robot simulation.

Deliverable: Spoken answers to 2 reported Robotics, Simulation, and Teleoperation question(s), under time.

Day 7 — Answer out loud: Hardware, CAD, and Diagnostics

  • Answer aloud, timed: How do you use CAD tools to verify physical clearances and component fitment in a robotic assembly?
  • Answer aloud, timed: Describe your process for diagnosing a communication failure on a CAN bus.

Deliverable: Spoken answers to 2 reported Hardware, CAD, and Diagnostics question(s), under time.

Behavioural preparation

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

How do you handle latency and packet loss in a real-time teleoperation loop?

Medium · Robotics, Simulation, and Teleoperation

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 debug a software issue that turned out to be a hardware failure. How did you i

Medium · Behavioral & Communication

Describe a time when you had to debug a software issue that turned out to be a hardware failure. How did you identify it?

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 mechanical constraints limit your software implementation?

Medium · Behavioral & Communication

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?

Explain a complex technical concept you recently learned to someone with a non-technical background.

Medium · Behavioral & Communication

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 prioritize tasks when working on a highly experimental prototype with shifting requirements?

Medium · Behavioral & Communication

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?