From our research
What this interview looks like
The interview boards of ISRO, DRDO, BARC and the defence PSUs look alike: five to eight senior scientists or engineers sit across a table, the chair asks you to introduce yourself and to name two or three subjects you are strongest in, and the panel then probes those subjects from first principles, often asking you to derive a result or work a rough calculation aloud on a whiteboard. Your final-year or M.Tech project is examined in detail, with the panel testing whether you personally understand every block of it. A short portion goes to motivation, willingness to relocate to a remote centre, and plans for higher studies. Real boards run from 30 minutes at a defence PSU to over an hour at BARC, where the interview alone decides selection. The ExamPilot mock compresses this into an 18-minute board with a chairperson, a technical member, a subject expert for the project discussion and an HR member, scored on fundamentals, project depth, problem-solving and fit.
How it is weighted
ICRB shortlists through the written test and then interviews; a minimum of about 60 percent in the interview is required, and the final merit in recent cycles has combined written-test and interview performance. Check the current advertisement for the exact weightage.
Who this is for
BE or B.Tech in Electronics, Mechanical, Computer Science and, in some cycles, Electrical, Civil and other disciplines, with first class (65 percent aggregate or CGPA 6.84 on 10). Candidates clear the ICRB written test and are shortlisted roughly in the ratio of five to eight per post for interview at an ISRO centre such as VSSC, URSC, SAC or SDSC.
The panel focuses on
- Two or three subjects you name yourself, probed from first principles with derivations talked through aloud
- Your final-year project: every block of your own block diagram, the numbers you measured and what you would change
- Rough calculations and orders of magnitude with correct units, especially where the panel changes one condition
- Awareness of what ISRO builds in your discipline: launch vehicles, satellites, avionics, ground stations, propulsion
- Honesty when you do not know, and the ability to use a single hint
- Willingness to be posted at Sriharikota, Thiruvananthapuram, Ahmedabad or Mahendragiri and long-term intent in the organisation
Step 1
Pick your subject
The expert on the panel probes these areas at the level of this post. Optional here; you can choose during setup.
Step 2
Choose how you want to be interviewed
1:1 interview
One interviewer runs every round and adapts the focus as you go. Lower pressure; ideal for a first attempt.
Dr. Raghunath Pillai
Chairperson
Panel interview · 4 members
Most realisticEach member leads their own round and hands over to the next. They hear each other, so a weak answer will be revisited.
Dr. Raghunath Pillai
Chairperson
Dr. Sharmila Rao
Technical lead
Prof. Debashis Sanyal
Subject expert
Ms. Neha Kulkarni
HR member
What to expect
5 rounds · 18 minutes
A research-organisation selection board compressed into 18 minutes: a short introduction with the chairperson on the candidate's project and interest areas, a long fundamentals round with a senior scientist who makes the candidate talk through derivations and first principles in their own discipline, a deep dive into the candidate's final-year or M.Tech project with a subject expert, a short aptitude and fit round with the HR member on why a research organisation, relocation and long-term intent, and a closing by the chairperson. The real boards sit five to eight scientists for 30 to 90 minutes, ask the candidate to name their favourite subjects and then probe those relentlessly, and reward a candidate who reasons aloud from basics over one who recites.
- Round 1
Introduction, project & interest areas
· 2:00Set the candidate at ease, hear a short account of their education and project, and get them to name the two or three subjects they are strongest in so the technical member can scope the fundamentals round.
Dr. Raghunath Pillai2–3 questionsup to 1 follow-up each - Round 2
Core fundamentals
· 7:00Test first-principles understanding of the candidate's discipline in the subjects they named: definitions, derivations talked through aloud, design calculations, orders of magnitude, and the assumptions behind the standard results.
Dr. Sharmila Rao4–6 questionsup to 2 follow-ups each - Round 3
Project deep dive
· 5:00Establish how much of the final-year or M.Tech project the candidate owns and understands, and whether they can defend design decisions, interpret their own results and think about what they would do next.
Prof. Debashis Sanyal3–5 questionsup to 2 follow-ups each - Round 4
Aptitude & fit
· 3:00Check motivation for a research or defence organisation over private industry, willingness to relocate to remote centres, awareness of the service conditions, and long-term intent including higher studies.
Ms. Neha Kulkarni2–3 questionsup to 1 follow-up each - Round 5
Closing
· 1:00Close the interview formally and courteously without revealing any assessment.
Dr. Raghunath Pillai1–1 questions
Sample questions
Scientist/Engineer ISRO SC interview questions
Questions panels commonly ask in the Scientist/Engineer ISRO SC interview, with what a strong answer covers. Practise them aloud with the AI panel.
- Control systems
You named control systems as a strong subject. A launch vehicle is aerodynamically unstable during ascent. How does the control system keep it on course, and what happens if the loop has too little phase margin?
What a strong answer covers
Explains sensing attitude with inertial sensors, computing corrections and actuating through gimballed nozzles or fins, and that low phase margin leads to oscillation or instability. A strong answer reasons in physical terms before maths. Avoid reciting Bode plot rules without linking them to the vehicle.
- Estimation
Estimate roughly how long a radio signal takes to travel to a geostationary satellite and back. Walk us through your numbers.
What a strong answer covers
Uses an altitude of roughly 36,000 km, the speed of light, and arrives at about a quarter of a second round trip, with units stated throughout. Avoid jumping to an answer without showing the assumption about distance.
- Spacecraft systems
Why does a satellite in low earth orbit need a thermal control system, when space is cold?
What a strong answer covers
Explains that heat transfer is by radiation only, the satellite faces intense sunlight on one side and deep cold on the other, electronics generate heat, and so coatings, insulation, heat pipes and radiators are used. Avoid saying space simply cools everything.
- Project
In your final-year project on a software-defined radio receiver, draw the block diagram in words and tell us which block you designed yourself.
What a strong answer covers
Describes antenna, front-end, mixing, filtering, sampling and demodulation stages in order, identifies the candidate's own block, and states one design decision with its reason. Avoid claiming ownership of blocks you only integrated.
- Propulsion
For mechanical engineers, why do rocket nozzles have a converging and then diverging shape?
What a strong answer covers
Explains that subsonic flow accelerates in the converging section, reaches sonic speed at the throat, and continues to accelerate supersonically in the diverging part, increasing exhaust velocity and thrust. Avoid answering only with a formula.
- Communication
If we doubled the data rate of a satellite downlink while keeping transmit power the same, what happens to the bit error rate, and how could you compensate?
What a strong answer covers
Reasons that energy per bit halves, so error rate rises, and suggests remedies such as a larger antenna, better coding or higher power. Avoid assuming data rate can be increased without trade-offs.
- Onboard software
For computer science candidates, how would you design software for an onboard computer so that a single memory error does not crash the mission?
What a strong answer covers
Mentions error-correcting memory, watchdog timers, redundancy, safe modes and rigorous testing, explaining why space radiation makes this necessary. Avoid relying only on testing after development.
- Posting
You may be posted to Sriharikota or Mahendragiri, far from big cities. How do you see your life and career there over the next five years?
What a strong answer covers
A realistic picture of living in a campus or township, the technical exposure such centres provide, and a genuine commitment beyond the first posting. Avoid saying you will request a transfer soon.
- Honesty
We just asked you something you did not know. What is the right thing to do in a board like this when you do not know an answer?
What a strong answer covers
Says honestly that you do not know, offers how you would reason or find out, and uses any hint given. Avoid guessing confidently, because the board will probe further and the guess will be exposed.
Reading is not rehearsing. Answer these out loud to an AI Scientist/Engineer ISRO SC panel that follows up like the real one.
Practise these questionsMeet the panel
Your AI interviewers
Distinct personas, voices and questioning styles, briefed on this post.
Dr. Raghunath Pillai
ChairChairperson
Group Director (Retd.), ISRO; led avionics and mission teams at VSSC and URSC; chairs scientist/engineer selection boards
Courteous, unhurried, listens for ownership and honesty.
Male voice · 4 languages
Dr. Sharmila Rao
Technical lead
Scientist G, DRDO; project director on a radar and electronic-warfare programme; technical member on RAC selection boards
Sharp, fast, first-principles, allergic to memorised formulas.
Female voice · 4 languages
Prof. Debashis Sanyal
Subject expert
Senior Professor, Homi Bhabha National Institute and Outstanding Scientist, BARC; faculty at the BARC Training School; member on OCES/DGFS interview boards
Patient, deep, interested in what the candidate actually did.
Male voice · 4 languages
Ms. Neha Kulkarni
HR member
HR business partner, IT services
Friendly, efficient, detail-checking.
Female voice · 4 languages
Languages
Answer in the language you think in
The panel asks in your chosen language. Switch mid-answer if you like.
- English
- हिंदीHindi
- Hinglish (Hindi + English)Hinglish
How scoring works
A report you can act on
Every round is scored on the rubric
Each interviewer scores only the criteria their round covers. Weights add up to your overall score out of 100.
Only what you actually said counts
Feedback quotes your own answers. Rounds you skip show as “Not assessed” rather than a zero.
Communication is always measured
Fluency, clarity, confidence and structure are tracked across the whole interview, in any language.
Pass mark, then a plan
You see the pass mark for this interview, your gaps, and the courses that close them fastest.
Scored on
- Core fundamentals40%
Correct, first-principles understanding of the candidate's own discipline: can state a law or theorem, explain where it comes from, talk through a derivation or a design calculation step by step, give orders of magnitude and units, and recognise the limits of a model. Red flags: memorised formulas with no idea of assumptions, wrong units, confident wrong answers that do not change under a hint.
- Project depth & ownership25%
Knows their own final-year or M.Tech project in detail: the problem, why the chosen method, the hardware or software actually built, the numbers measured, what went wrong and what they would do differently. Can defend design choices and admit what a guide or teammate did. Red flags: cannot explain a component of their own block diagram, quotes results they cannot interpret, claims the whole team's work as their own.
- Problem-solving under probing15%
When given a new problem or a twist on a known one, sets it up systematically, states assumptions, estimates before computing, uses hints productively and checks the answer for sanity. Red flags: freezes, guesses randomly, or argues instead of reconsidering when shown an inconsistency.
- Communication, aptitude & fit20%
Explains technical ideas clearly and concisely in English or Hinglish, says 'I do not know' honestly, and gives a credible reason for a research or defence organisation over private industry, with realistic expectations about pay, postings at remote centres, bonds and the slow pace of large programmes. Red flags: bluffing, salary-only motivation, unwillingness to relocate without saying so plainly.
Pass mark 60 / 100 · Scientist / Engineer selection board (ISRO, DRDO, BARC, defence PSUs)
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