My interview was scheduled on Feb 29th at VSSC . They asked us to report by 8:00 in the morning. I reached by 7.30 AM. At around 10.30 AM, document verification took place following which they provided a sequence number for the interview. It was a long wait of a whole day. At last, they called me for interview at around 7:00 PM. The interview session itself was pretty short, roughly 10 minutes or so.

Panel was composed of around 7 to 8 interviewers. They asked what I was doing in Samsung (I have two years  of work experience). I talked about the projects I was working on. However, they didn’t ask me any questions on those projects, as those were related to Tizen and network simulation.

Panel: What all are the subjects you are interested in?

Me: Anything apart from Software Engineering (As it was not in GATE syllabus, so I didn’t prepare 😛 )  (Everybody was laughing). I was told that they were there to ask questions from that subject only.

The following are the questions asked in interview. I’m not providing answers, since most of those cover the basics.


  1. Considering that Software Engineering didn’t even exist in 1970, why is it so popular now-a-days?
  2. What is difference between error and bug?
  3. What is cache, direct mapped cache and set associative cache?
  4. What does object file contain?
  5. Is collision possible inside router, hub and repeater?
  6. Explain exponential back off algorithm.
  7. What is RTT in Ethernet?
  8. Which direction will the cross product of two vectors be in?
  9. In set theory, they asked basic definition of union, intersection etc.
  10. How will you run if one program refers variables in other file [like static, global] in Linux?

On final year project:

My final year project was optical character recognition of Telugu characters.

  1. What is difference between node and neuron?
  2. How weights are updated in neural networks?
  3. Is it necessary to have summation function?

Written test and interview are so easy that if you prepare well for GATE, you can nail it down without much pain. In written examination, more than 95% questions were just copy-pasted verbatim from previous years’ GATE question papers. During the written test, I reported a few errors to the invigilator and was told that I’d get marks for those questions if I just attempt it. What more annoying was, the invigilators corrected answer options to almost four to six questions while the examination was in progress. Also, there were a bunch of questions with incorrect answer keys, even for questions directly copied from previous years’ GATE question papers.

For the curious ones, I stood 6th in the written examination by scoring 149 while the topper got 153. In the interview, though I am not sure what they could judge in a brief interaction of ten minutes, I scored 75.38% while my overall place being 16th in final the merit list. In the whole process, I felt bad about not receiving any prior information on dates of crucial milestones, e.g. result of written examination, interview, issuance of appointment letter etc. Kind of I seem to loss my energy in the waiting period itself. Worse is, even if you call them, most of the time they provide false information or gives out some “canned” reply. Not only for me, but the story is the same for many candidates as you can read here. It didn’t appear to me that they were recruiting for as responsible and esteemed a designation as “Scientist” is. ISRO is not a private organisation. It can be left without paying any bond amount, unlike many private organizations. It’s the prestige of our country. I hope it will improve soon.

Please read this post before reading this to know about the interview process and it was written before the interview results were announced, so can find no bias in it. In this post, I will be answering some questions based on the previous statistics that I have collected.

  1. Your Interview will be scheduled at morning 8.00 AM but they can call you any time before 9.00 PM. I was  called for the interview at around 7.10 PM and there were three more candidates left after me in Thiruvananthapuram. A male candidate was interviewed at around 9.00 PM in Delhi (another interview center). Don’t loose your energy/get tired by simply sitting. Often, they will provide refreshment, also you can interact with the other colleagues if you are that kind of a person. So, book your return ticket for the next day to be on the safer side. This is not applicable to the lady candidates as they are interviewed first.
  2. Will I be not selected if I am interviewed very late, as interviewers might already have selected the required candidates? Will they be less interested to interview me? Absolutely not. I was interviewed fourth from the last, still I got selected while having a good rank at the same time. Moreover, the next person sitting after me also ranked good and got selected. The interviewers are experienced enough to know our feeling when candidates are interviewed so late. Be cool/positive and don’t worry on this.
  3. What are the subjects to be prepared? Will they ask from our final year project? Every questions will be from your favorite subjects if you are lucky and if not, they will ask some questions beyond your comfort zone. There will be no HR questions. They will question your project if you passed out recently, say 2-3 years back. Its good to prepare the project, at least the technique or technology you have used in that.
  4. I got All-India Rank (AIR) < 23 in written test and the number of positions advertised are 23. Will I be selected for sure?. No. This year (2016) the top 5 rankers in the written test were not selected in the interview. Do prepare for the interview. See the attachment at the end for the proof of the same. There is an equal chance to get selected even for the last shortlisted candidate, so don’t skip the interview.
  5. I have no experience/passed out last year with no job. Is my probability of getting selected looks bleak?. No. Though I didn’t mention my experience/job, I was selected. I had no questions regarding the year I have a career gap in. You might be asked questions when you are unemployed more than a year. Stay prepared for that. I didn’t mention my experience/job because I don’t have any notable skill/experience acquired from my company because of various reasons.
  6. I am a girl candidate and selected for the interview. Will I be selected for the post as ISRO have mentioned that “Government strives to have a workforce which reflects gender balance and women candidates are encouraged to apply”?. Obviously women candidates slightly have an edge over their counterpart in the process. However, to be noted that it’s a rare event that you will be selected if you don’t perform well in the interview. Prepare for the worst and hope for the best. For the male candidates, don’t ever think of this because this policies are not in our hand to be changed. Do your best and hope for the rest.
  7. Is scientist ‘SC’ not a permanent post in ISRO, because in their job advertisement they mention that: “The posts are temporary, but likely to continue“? As quoted by Dipanjan (worked in ISRO), it’s a permanent post with probation for initial few months. That’s why it’s written like that. Saying that, I have never seen/heard someone getting terminated during the probation. The notification is always phrased like that, using legal jargon. It will definitely be permanent barring special cases, e.g. one commits a crime etc.
  8. And regarding the documents, they will verify the documents (mark sheets, certificates…) before attending the interview. Be sure to bring all the original documents and attested copies that they mention in the call letter. They are strict/cautious in this process, for instance they even summed up the marks of my 10th, 12th standard mark sheets while the total marks was already written in the mark sheet by the issuing board :). Double check while filling up the online application form as they cross verify against it prior to the interview.

Below, I have attached all the documents/results for this year(all branches):


The interview was scheduled to be conducted at 8.00 AM (28th Feb 2016), I reached VSSC ATF centre at around 7.30 AM. After the document verification, they allotted numbers for each candidate base on the following priority: (i) Girls (ii) Those who booked their tickets on the same day (actually on the interview letter they mentioned that in worst case, it needs two days for the interview). As I booked the ticket for the next day evening, they called me around 7.10 PM.

There were seven peoples sitting in a semi-circle. They didn’t ask me about myself or what I do. Firstly, they questioned me about my project work. As soon as I started explaining, they interrupted me (seemed that they were either not interested or because of time constraint since there were three more peoples waiting to be interviewed). Next,  I was asked what my favorite subject are. I mentioned (i) Operating Systems (ii) Data structures (iii) Computer Networks in order. The interviewer who was sitting in the middle asked others to start off with Data Structure.

Here is a list of questions I was asked and those which I remember now:

Interviewer – I:

  • What is binary heap? Types? Properties? [Answered]
  • Application of the Heap [Answered]
  • Abstract data type and its use [Answered]
  • Stacks, Grow-able stack and queue and their use [Answered]
  • Dynamic memory allocation [Answered]

Interviewer – II:

  • Questions regarding routing algorithm [Answered]
  • A question on FILE’s in C: The temporary buffer of file [Answered as “RAM”, I don’t know it is right or not]
  • WAN protocol [Not answered]

Interviewer – III:

  • Memory leak in Java [I didn’t know about this in Java, offered an explanation w.r.t. C instead]
  • C pre-processor [Answered]
  • Phases of compiler [Answered]
  • JAR file in Java. [I admitted that I am not familiar with Java. What all I could remember is using JAR file in my Nokia S40 series. They didn’t seem to be very  impressed]

Important points:

  • For the interview round, they didn’t expect an one word brief reply. There were some discussions happened for every answer like Implementation ,application of it etc..They will help if you stuck but they wanted the answer from your mouth.
  • The questions were mostly based on the feedback. Meaning that, the next question will be based on your answer for current question. So think twice before you answer.
  • As you see from my interview questions that they can ask you from any computer science subject[not only on your favorite  subjects].Even I had in depth discussion on Compiler design which I don’t have in my B.Tech course ware.
  • For some of the interviewee’s the questions were from Mathematics notably from Geometry, Discrete Mathematics etc.
  • One candidate, who works in a PSU, was not allowed to attend interview because of not having NoC letter from his company.
  • The candidates who attended the interview were quite knowledgeable and experienced. Most of them passed out before 2011 or 2012. Probably, only two of them including me were 2015 pass-outs[w.r.t boys]. The companies they were working include Adobe, Samsung research, Adobe, GATE CSE tutors , Asst. Professors, IIsc and IIT M.Tech. students and from PSU’s.
  • Some of the candidate’s came there were attended interview before hand in ISRO[previous year’s].

To conclude, you should be  top of your game and need a bit of luck in terms of questions they start with.

Scenario: Interview for the promotion to “Scientist/ Engineer D”
Panel chairman: Shoots out the initiating question
Interviewee       : Oh shit! Couldn’t answer that one

Let me introduce the interviewee. It’s me; Soumen Kumar Das, a CS graduate. I joined ISRO in 2012. Luckily the fiasco in the opening question didn’t dictate the decision of Departmental Promotion Committee (DPC)! I got promoted with flying colors and currently continuing over there as a “Scientist/Engineer D”. That gives me a feel that I have some sort of authority to present my holistic experience of spending more than three years at ISRO; solely based on my personal views (and biases, may be :))

Working life…. Living work in ISRO” – the two phrases, though look similar, there is a thin line in between. Working life in ISRO very much depends on the division and the bosses you are working in and under. In a certain division, if the quantity of work is suitable for ten people, then the division tries to maintain a count of  more or less six to seven personnel. So, there is a lot of work to do. Unlike other government sectors jobs, of course, here you will be having more responsibilities and more ways to work at the same time. Nature of bosses does vary, too. A flexible one gives the nature of work as asked by you from the responsibility set. Some are very rigid or helpless to provide so. Some of them are very much unaware of the correct deadline to set and only thinks that providing less time builds up pressure to make the employees work more and more. Some are very cool and if knows that the particular colleague under him is sincere, then does not intervene. Not only bosses, but the peers are enthusiastic and passionate about research and development will never slow you down and keep updated. If all of the above mentioned points are suitable for you, then it can be easily understood that working life will be enjoyable allowing you to thrive your knowledge.

Living work in ISRO depends on the type of work you want vs. the type you get. The aerodynamicist, mechanical, electrical, chemical engineers mostly get interesting and challenging works. But for computer science guys the probability of getting interesting work is a rare event at Vikram Sarabhai Space Center (VSSC). Fortunately, I have got an interesting domain allocated where I’m working in high performance computing in the SAGA Supercomputer  division in ISRO. I’m playing with hardware, software and their interaction at a finer level. I’m living work here. But, inside any division there are lot of scopes where one can gain new vision, if worthy enough, then from organization one will receive all the required help. Living work has another view mostly people like me. I think many among you will also agree that one can live work life in a very productive manner if his/her home town is within a range of 300 kms. such that, at least, he/she can come back home around weekend. This is possible for very few lucky people for whom their stay at ISRO is very enjoyable.

An engineer and an ISRO engineer is different as far as social and personal lives are concerned. This job requires ones 24×7 involvement at times. You are expected to be there irrespective of time or situation in case of any emergency. Otherwise, the job life is somewhat “cool“. Certainly, ISRO is a brand name which is recognized all over the world. It will specifically be of utmost use if someone works in a valuable project. That way, the brand value of ISRO can be “traded” in research projects. As a Scientist/Engineer, one receives respect and gratitude from others that may enlighten some people. But, the main thing is life will be joyful and happening. Don’t expect any huge compensation or any extra reward as at the end of the day it’s a Government of India job. Salary is comparable to an ordinary central government employee with a pay band 3. Therefore, come and join if you like the prospect above. For recruitment, please check out ISRO website.


Compared to other Govt. organizations, ISRO is quite different in certain aspects. Let me point out a few.


  1. Starting from time of late Dr. Vikram Sarabhai, Dr. Sathish Dhawan and many other, ISRO has contributed significantly in different domains related to space science. Being the only player in this field in India, it is now a “brand”, a name which many of us want our names to attach to. Being an ISRO-ian gives you a higher societal respect. It is a sort of monopoly. Like IT industries, if five more organizations start working on the same, then the glory which is there at present might get faded out in future. Nonetheless, you’ll yourself feel proud while dealing with classified national information which are otherwise inaccessible from outside the organization.
  2. The environment is academics-friendly. At Vikram Sarabhai Space Center (VSSC), you’ll be having one large library, free subscriptions to IEEE and other paid journals without paying a single penny from your pocket. Sometimes, you’ll be sent to different workshops held at various IITs and IISc being sponsored by organization  If the sponsorship amount exceeds Rs/-5,000, it is subject to the approval of an academic committee. Otherwise, your Division Head’s approval is sufficient. Also apart from these external seminars and workshops, they arrange internal seminars and meetings chaired by people out here for years. Professors from other institutes, e.g. BARC, are also invited to deliver lecture.
  3. You’ll get to know space science and technology closely. Computer Science people generally work in launch vehicle software development which are used either directly on-board of a flight or related to development of such software indirectly. While working in an IT company, you’ll never get a chance to get involved in development of a software which will fly thousands of kilometers away. Have you ever been surprised thinking that even the smallest of bug present in such a software, e.g. floating-point rounding issue, can cause a mission to fail leading to a wastage of 500-600 crores of INR? How are such pieces of software quality-assured? How is the offline simulation done? How much time is involved from the development of such a real-time software to be quality-approved? Or have you ever dreamt of developing customized system tools, e.g. RTOS, Compiler, Assembler, Linker, Loader, Simulator etc.? Electronics people generally work in designing and fabricating electronics packages. Some of them, again, in quality-assuring the packages developed. And ISRO is “the place” for people fro Mechanical background. The whole of the launch vehicle, satellite are realized by their ideas. Depending on the division you have been put in, you may get chances to travel to other ISRO centres, especially SDSC-SHAR, the only launch port of India. I went there twice during my last one year of stay at ISRO. Believe me, it’s an wonderful experice to touch a launch-vehicle which’ll be flying away tomorrow. Success of every mission will make you feel prouder as your service is towards the nation.
  4. Coming to professional benefits  you’ll be entitled to availing CHSS (Contributory Health Service Scheme) which will offer you and your dependents an unlimited medical coverage. PRAN, the new pension scheme (NPS – Tier – I) is there to support your post-retiral life. Annually, a decent sum will get credited to your account as professional update allowance. For the post of Scientist/Engineer – ‘SC’, it is Rs./-10,000 presently. Mostly the working hours is limited to 8 hours starting from 9:00 AM to 5:00 PM. The post what is offered is of a Class-A gazetted officer. After the closure of one year probation period required for your background check by local police station and CBI, you can get one seal of yours to “attest” documents. Something funny, initially! Apart from that, the establishment is quite complete because of having a staff quarter, a post office, a bank and a health-center at reasonable distance from office. The area is well-guarded by CISF (Central Industrial Security Force) people. At canteens, the food is highly subsidized.
  5. After you finish three years of service life here, you can appear GATE as a sponsored candidate to get a relatively easy seat in IISc. and IITs. Given the level of competition in GATE now-a-days, this is a chance to fulfill the dreams of those who couldn’t make it through.
  6. Till now, the service is no-bond. You are free to resign from the organization at any point of time without paying any compensation.
  7. You will come in touch will people whom you have dreamt only during IITP – ISRO Induction Training Program conducted to induce you to ISRO.
  8. Like any other Govt. job, your future is assured. Nobody will fire you the next day once your back ground check is complete and found clean.
  9. Job deadlines are there, but depending on the nature of assignment, it is quite flexible. “Slow but steady” is the key here.
  10. Work environment is less hostile and less competitive compared to any private company. But those who’ll expect usual “sit-back-and-relax” type environment what is seen in many other Govt. organizations, a severe shock is awaiting them!


  1. Common disease to all Govt. organizations is being unbelievably slow-moving. ISRO is also affected by the same in certain cases. As an example, last year one of my friends resigned with a notice period of one month. In spite of his earnest efforts, ha failed to acquire the relieving letter on the day of his resignation. I was with TCS, a privately held MNC, which required only half a day to process my resignation! Thumb rule for those who have worked in a private company, “Never expect nothing to happen lightning fast here”.
  2. Salary wise it is never comparable to private companies. Though the initial salary may be higher than the starting salary offered by an average IT company, the growth rate is pathetic. For all the promotions, at least four years or more gaps are needed. Worst is, it may get delayed failing to satisfy DPC (Departmental Promotion Committee). Those who are having M.Tech. as their highest qualification, they will get the first promotion in two years instead of four years unlike B.Tech candidates, but subject to the condition that 1/3 of their course tenure must have to overlap with their service period in ISRO.
  3. For Scientist/Engineer – ‘SC’ post, around Rs./-3,500 will be deducted from your salary every month. If you resign prior to your 60 yrs. of your age, that amount will not be refunded back. Our honorable Govt. has not yet decided any policy for such employees. Also, 50% of EL (Earned Leaves) will be en-cashed in case of resignation.
  4. Scientist quarters are not readily available after your joining. It may take a couple of years or so as there will be many people in the queue ahead of you. Bachelors quarters are immediately available, but the problem is that you can’t allow anyone to stay three along with you, even parents.
  5. Until and unless you finish three years of your service here, you can’t apply for either academic sponsorship or study leave. Even if you go as a sponsored candidate after three years, you have to serve a mandatory service period of five years after joining back, otherwise some ~10 Lakhs of bond amount has to be paid from your pocket.
  6. A word of caution to people who have worked in any average IT company. Neither environment nor life is as “shiny and gorgeous” as it is in an IT company.
  7. Unless having special permission, one can’t carry mobile phones inside the office premises. It takes some time to get friends and relatives trained to ISRO culture of not attending calls during office hours.
  8. A gazetted officer, as you will be, may be called in weekends, theoretically 24*7. Saturday and Sunday are the usual holidays, but in certain occasions depending upon the workload in the division you are working in, you may have to work the whole day. “Stay-back” is an usual term here. In such cases, you’ll get car drop to you place.
  9. There are certain division (I won’t name those), though very few, are carrying out “bogus” activities which are not anyway related to launch vehicle. If you are that much unlucky, you won’t get the feel of being in ISRO. To make the matter worse, there is no formal procedure for division change and location transfer. You don’t have any control on which division you’ll be put in prior to joining. This is solely an organizational decision.
  10. Paper work is more here. People are still relying on signature in black on a white paper rather than signing it digitally!
  11. Organizational knowledge management is very poor. Information is either absent or scattered.
  12. Most of the PCs in the workplace are Intranet-only. Only few restricted Internet nodes are available. The constraint is due to restrict the free flow of information from inside the organization. Even the proxy allows only 25 KB of upload from behind. If a mail-chain becomes larger, specially containing inline images, it becomes impossible to send.
  13. In my case, the date of publishing of the recruitment advertisement and date of joining had gap of 13 months contrary to few hours in case of IT companies.
  14. Concept of resource/energy-saving “green” office is still far away.

Now rate and evaluate ISRO yourself. Enough input has been given. 🙂