Real-Time Innovations (RTI) · Software Engineer
Updated · 2026-10-02

Real-Time Innovations (RTI) Software Engineer
Interview Guide

THE 60-SECOND BRIEF

A Software Engineer at Real-Time Innovations (RTI) plays a pivotal role in shaping the future of autonomous systems, robotics, and mission-critical infrastructure. As the leading provider of messaging middleware for the Industrial Internet of Things (IIoT), RTI relies on its engineers to build and maintain high-performance, distributed systems that operate under extreme constraints. You will be working with the Data Distribution Service (DDS) standard, ensuring that data moves reliably and in real-time across complex, heterogeneous networks. This role is not just about writing code; it is about system-level thinking. You will contribute to products that power everything from autonomous vehicles and medical devices to aerospace defense systems. The impact of your work is measured by reliability, low latency, and scalability.

This guide is scoped to a Software Engineer candidate at Real-Time Innovations (RTI).

Real-Time Innovations (RTI) candidates report 3 rounds over 3-5 weeks. The stages below are what candidates describe, not a published process.

C programming (C)TCP vs UDPProblem solving / algorithmic thinking

24 min read

Browse Software Engineer questions

See the practice prompts

11Practice promptsAcross five skill areas

A Software Engineer at Real-Time Innovations (RTI) plays a pivotal role in shaping the future of autonomous systems, robotics, and mission-critical infrastructure. As the leading provider of messaging middleware for the Industrial Internet of Things (IIoT), RTI relies on its engineers to build and maintain high-performance, distributed systems that operate under extreme constraints. You will be working with the Data Distribution Service (DDS) standard, ensuring that data moves reliably and in real-time across complex, heterogeneous networks. This role is not just about writing code; it is about system-level thinking. You will contribute to products that power everything from autonomous vehicles and medical devices to aerospace defense systems. The impact of your work is measured by reliability, low latency, and scalability. Successful engineers here are those who thrive on solving deep technical puzzles, possess a strong grasp of networking and concurrency, and are capable of bridging the gap between low-level system performance and customer-facing requirements. ##### Tip The culture at RTI is known for long employee tenure and a deep commitment to technical excellence. Be prepared to discuss your long-term interest in the company, as they value candidates who want to build a career rather than just fill a role.

01

Recruiter Screen

reported

Initial screening call with a recruiter to assess your fit for the role.

What to demonstrate

  • Initial screening call with a recruiter to assess your fit for the role
  • Depth in C programming (C)

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.
Real-Time Innovations (RTI) Software Engineer candidate reports ↗
02

Technical Interviews

reported

Multiple technical interviews that may include live coding, architectural discussions, or technical presentations.

What to demonstrate

  • Multiple technical interviews that may include live coding, architectural discussions, or technical presentations
  • Depth in C programming (C)

How to prepare

  • Answer aloud and timed: These help the team understand your communication style and your approach to collaborative problem-solving. Describe a time you had to explain a complex technical concept to a non-technical stakeholder. What motivated you to apply to RTI specifically? Tell us about a project where you faced a significant technical roadblock—how did you resolve it? How do you handle feedback during a code review?
  • Work C programming (C) until you can explain it without notes
Real-Time Innovations (RTI) Software Engineer candidate reports ↗
03

Team Interaction

reported

Engagement with engineering peers and management to evaluate team fit.

What to demonstrate

  • Engagement with engineering peers and management to evaluate team fit
  • Depth in C programming (C)

How to prepare

  • Work C programming (C) until you can explain it without notes
  • Work TCP vs UDP until you can explain it without notes
Real-Time Innovations (RTI) Software Engineer candidate reports ↗

PracHub editorial advice for the preparation topics above.

01

Prioritize clarity

When solving coding problems, prioritize explaining your logic over writing perfect syntax immediately.

02

Prepare for the presentation

If you are asked to give a technical presentation, choose a topic you are passionate about, but ensure it relates to the technical work at RTI.

03

Know your resume

Be prepared to discuss every project on your resume in detail. You will likely be asked to explain the design decisions you made.

04

Ask meaningful questions

Use the time at the end of the interview to ask about the team’s current technical challenges or the company’s long-term roadmap.

05

Don't ignore the basics

Review fundamental networking concepts and OS internals before your onsite; these are often the "differentiators" between candidates.

Choose a category, try a prompt, then open its approach, worked solution or follow-up when you need it.

8 technical prompts0 include a worked solution

These questions test your proficiency in low-level programming and your understanding of how software interact

medium
Technical Foundations (C/C++ & OS)

These questions test your proficiency in low-level programming and your understanding of how software interacts with hardware. Explain the difference between the heap and the stack. How do you manage memory in C to prevent leaks? How does a mutex differ from a semaphore in a multi-threaded environment? What is the difference between TCP and UDP, and how would you implement reliability on top of UDP? Explain the role of a virtual memory system in an operating system.

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?

These assess your analytical approach and ability to write clean, efficient code under pressure. Given a point

medium
Problem Solving & Algorithms

These assess your analytical approach and ability to write clean, efficient code under pressure. Given a pointer to a linked list, how do you detect a cycle? Write a function to reverse a string in place. Solve a standard data structure problem (e.g., array manipulation) using a live coding platform. How would you design a simple thread-safe queue?

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?

Identify the heaviest tenants in a five-minute window under memory pressure

medium
top-kheavy hittersstreaming

The edge service handles about 3,000 requests per second across roughly 50,000 tenants, peaking near 9,000. Expose the 50 heaviest tenants by request count over the trailing five minutes so limits can be tightened before one tenant's backfill starves the fleet. You may not retain five minutes of raw records. Give the exact solution and its memory, then the bounded-memory approximation with its error stated as a formula, and say which you would ship and at what tenant cardinality that choice changes.

Approach
  1. Do the exact version first, because it is affordable at this cardinality: a ring of 300 one-second counters per tenant, advanced lazily, is 1,200 bytes of counters per tenant and roughly 60 to 90 MB for 50,000 tenants with overhead. Carry a running total and subtract the bucket you overwrite so a window read is O(1) rather than 300 adds.
  2. Extract the top 50 with a size-k min-heap over the tenant sums: O(d log k) for d tenants, against O(d log d) to sort them all. Maintaining the heap continuously instead of on query requires a tenant-to-heap-index map, because incrementing a count already inside the heap means sifting from a known position, and without that map you rebuild the heap on every request.
  3. State the approximation precisely rather than gesturing at sketches. Misra-Gries with m counters retains every item whose true count exceeds N/(m+1), and each retained count underestimates the truth by at most N/(m+1). With m = 1,000 and N = 900,000 requests in the window the error is roughly 900 requests, which is fine for spotting a tenant sending 50,000 and useless for ranking two tenants 200 apart.
  4. Say what breaks when the window slides: Misra-Gries and Space-Saving are insert-only and cannot be decremented as records age out. The workable construction is one summary per sub-window, say ten seconds, with 30 summaries merged at query time, and the merged error is the sum of the per-summary errors, so the bound degrades linearly in the number of sub-windows.
Follow-up
  • The heaviest tenant is heavy because of one export job rather than user traffic. Should the limiter treat those as the same tenant?
  • Two tenants sit tied at the boundary of the top 50. Does your answer flap, and does the flapping matter?

Built from the rounds and topics Real-Time Innovations (RTI) candidates report.

Small steps. Visible outcomes.0 / 7 completed
ONE WEEK · YOUR PACE

Prepare, practise & reflect

One practical outcome each day. Spend longer where you need it.

0 / 7 done
01Map the Real-Time Innovations (RTI) loop
  • Write out the reported sequence: Recruiter Screen, Technical Interviews, Team Interaction.
  • 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.

02Work C programming (C)
  • Spend the session on C programming (C), which Real-Time Innovations (RTI) candidates report being tested on.
  • Write one worked example in C programming (C) and time yourself on it.

Deliverable: One timed worked example in C programming (C).

03Work TCP vs UDP
  • Spend the session on TCP vs UDP, which Real-Time Innovations (RTI) candidates report being tested on.
  • Write one worked example in TCP vs UDP and time yourself on it.

Deliverable: One timed worked example in TCP vs UDP.

04Work Problem solving / algorithmic thinking
  • Spend the session on Problem solving / algorithmic thinking, which Real-Time Innovations (RTI) candidates report being tested on.
  • Write one worked example in Problem solving / algorithmic thinking and time yourself on it.

Deliverable: One timed worked example in Problem solving / algorithmic thinking.

05Answer out loud: Technical Foundations (C/C++ & OS)
  • Answer aloud, timed: These questions test your proficiency in low-level programming and your understanding of how software interacts with hardware. Explain the difference between the heap and the stack. How do you manage memory in C to prevent leaks? How does a mutex differ from a semaphore in a multi-threaded environment? What is the difference between TCP and UDP, and how would you implement reliability on top of UDP? Explain the role of a virtual memory system in an operating system.

Deliverable: Spoken answers to 1 reported Technical Foundations (C/C++ & OS) question(s), under time.

06Answer out loud: Problem Solving & Algorithms
  • Answer aloud, timed: These assess your analytical approach and ability to write clean, efficient code under pressure. Given a pointer to a linked list, how do you detect a cycle? Write a function to reverse a string in place. Solve a standard data structure problem (e.g., array manipulation) using a live coding platform. How would you design a simple thread-safe queue?

Deliverable: Spoken answers to 1 reported Problem Solving & Algorithms question(s), under time.

07Answer out loud: Behavioral & Situational
  • Answer aloud, timed: These help the team understand your communication style and your approach to collaborative problem-solving. Describe a time you had to explain a complex technical concept to a non-technical stakeholder. What motivated you to apply to RTI specifically? Tell us about a project where you faced a significant technical roadblock—how did you resolve it? How do you handle feedback during a code review?

Deliverable: Spoken answers to 1 reported Behavioral & Situational question(s), under time.

Expand any day for tasks and deliverables. Your progress is saved on this device.

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

These help the team understand your communication style and your approach to collaborative problem-solving. De

medium
Behavioral & Situational

These help the team understand your communication style and your approach to collaborative problem-solving. Describe a time you had to explain a complex technical concept to a non-technical stakeholder. What motivated you to apply to RTI specifically? Tell us about a project where you faced a significant technical roadblock—how did you resolve it? How do you handle feedback during a code review?

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 callers you do not own that their integration breaks

medium
deprecationcompatibilitystakeholders

A field in a write endpoint's response must change shape. You own the endpoint; you do not own the four internal callers or the outbound webhook consumers who read it. Describe a deprecation you were responsible for: what you shipped first, how you established who was actually reading the field, the window you gave and what set its length, what you did about the consumer who never moved, and how you decided removal was safe. Name the signal you used, not the announcement you sent.

Approach
  1. Establish the reader set empirically rather than from a wiki of owners: per-field usage counters keyed by principal, or access logs attributed to a consumer. State the blind spot of whichever you pick, since a consumer that reads the field only on a monthly job will not appear in a week of logs.
  2. Ship additive first. Populate the new field alongside the old one so no reader is forced to move, which is also what keeps a rolling deploy safe, because old and new instances answer the same requests at the same time and a rollback must still find the old shape present.
  3. Set the window from the slowest legitimate consumer's release cadence, not from your calendar, and decide separately what to do for a consumer with no release process at all, such as an external webhook endpoint you can only email.
  4. Convert silence into evidence before you rely on it: a short, low-traffic removal window that makes a still-dependent consumer fail visibly and loudly while you are watching, rather than at three in the morning after you have moved on.
Follow-up
  • How would you detect a consumer that reads the field only during a monthly export?
  • One caller refuses to move and has a commercial relationship behind it. What changes in your plan and what does not?

Narrate an outage you owned from page to postmortem

hard
incident responseblast radiuspostmortems

Pick an incident you personally drove, ideally one where writes were affected rather than reads. In six to eight minutes: state the symptom as it first appeared on a dashboard, the blast radius you established before you knew the cause, the mitigation you applied and when, the mechanism you eventually proved, and the follow-up that would prevent a repeat. Bring numbers: error rate, tenants affected, minutes to mitigate, minutes to resolve. If you cannot name what you measured, choose a different incident.

Approach
  1. Open on the signal rather than the cause: which metric at which percentile moved, on which service, at what time, so the listener follows the same evidence you had rather than a conclusion you already reached.
  2. Separate mitigation from diagnosis out loud. State what you did to stop the bleeding (flag off, shed traffic, drain a lease, roll back a deploy) and say plainly that you did it before the mechanism was known, because those are two jobs with different deadlines.
  3. Establish blast radius in countable terms: how many tenants, how many writes, and crucially whether the effect was loss or only delay. An append-only revision table or a pending outbox row means the change survived and the projection was merely behind, which is a repair rather than a data-loss incident.
  4. Prove the mechanism instead of asserting it. Name the trace span that grew, the plan that flipped to a sequential scan, the lease that expired, plus one alternative you ruled out and the signal that stayed flat while you ruled it out.
Follow-up
  • What would you do differently in the first five minutes, given the same dashboard and no more information?
  • Which follow-up action did you deliberately not take, and why was dropping it the right call?
  • 01

    These help the team understand your communication style and your approach to collaborative problem-solving. Describe a time you had to explain a complex technical concept to a non-technical stakeholder. What motivated you to apply to RTI specifically? Tell us about a project where you faced a significant technical roadblock—how did you resolve it? How do you handle feedback during a code review?

  • 02

    A field in a write endpoint's response must change shape. You own the endpoint; you do not own the four internal callers or the outbound webhook consumers who read it. Describe a deprecation you were responsible for: what you shipped first, how you established who was actually reading the field, the window you gave and what set its length, what you did about the consumer who never moved, and how you decided removal was safe. Name the signal you used, not the announcement you sent.

  • 03

    Pick an incident you personally drove, ideally one where writes were affected rather than reads. In six to eight minutes: state the symptom as it first appeared on a dashboard, the blast radius you established before you knew the cause, the mitigation you applied and when, the mechanism you eventually proved, and the follow-up that would prevent a repeat. Bring numbers: error rate, tenants affected, minutes to mitigate, minutes to resolve. If you cannot name what you measured, choose a different incident.

PracHub preparation framework ↗
How difficult are the technical interviews?

The difficulty is generally considered moderate to high, as they focus on deep system-level concepts rather than just "LeetCode" style puzzles. Expect to be challenged on your understanding of how code interacts with the underlying OS and network.

Real-Time Innovations (RTI) Software Engineer candidate reports ↗
How long does the process take?

The process typically takes one to three months, involving several rounds of interviews. RTI is generally prompt with feedback, so you will rarely be left guessing about your status.

Real-Time Innovations (RTI) Software Engineer candidate reports ↗
Is there a specific coding language I should master?

C++ is the primary language used at RTI. Being highly proficient in modern C++ standards and understanding memory management in C will be your greatest advantage.

Real-Time Innovations (RTI) Software Engineer candidate reports ↗
Does RTI offer remote work?

Policies vary by location and team. Be sure to clarify the expectations regarding office attendance or remote flexibility during your initial recruiter screen.

Real-Time Innovations (RTI) Software Engineer candidate reports ↗
What topics does Real-Time Innovations (RTI) test in interviews?

Real-Time Innovations (RTI) interviews most often cover Concurrency, Distributed Systems, Marketing Analytics, C programming (C), and Physical AI. The exact emphasis depends on the specific role you apply for.

Real-Time Innovations (RTI) Software Engineer candidate reports ↗
Sources & methodology 3 sources ↗

No official company page is cited. Rounds and questions come from candidate reports and PracHub editorial material; each source shows the date it was read.