I am software professional having enormous experience of software development (viz. in C++) and have worked in many prominent multi-national software companies and in various domains.
Few years back I came out of job. Then out of my own passion I developed a server framework in C++ (which is more than 65 thousands of lines of code). I've designed it, coded it, tested it for high performance and released it. I've done it all by myself. It is all single handed work done sheer out of my own passion. Now I have made it all open source where-in I have created its detailed design documentation as well (available on GitHub). I also launched a website and an Android App based on this framework.
Despite of doing all this, whenever I face interviews (currently I am looking for job) interviewers sounds completely disregarding the work that I have done. They do not even seems caring to look at my source code or documentation, and simply ask me questions like:
Can you please tell us how can you design XYZ using C++ ?
(This XYZ can be like anything for e.g. "XML format", "Vehicle parking system", "Files processing software", "Cache storing application" etc)
I am finding this is truly annoying and painful. How can someone design something in quick few minutes right in front of them & there itself? I mean I surely can design it all, but I need some time to design (And I believe many do). But here I cannot buy time or space for myself. They want me to design there itself right in front of them while they are staring at me. Then helplessly I go on telling them anything what comes to my mind at that moment. Sometime I experience nervous breakdown also. And as a result get rejected in the interview.
I must note: It also has happened that I came up with perfect design as an answer for such questions but after interview is over. For example, in one interview I was asked "How would you design parking system when given there are multiple parking slots and for various types of vehicles?" Then after coming out of the interview, I realized I should have told "Parking, Vehicle, Slots are classes. Parking will have member objects of class Slot. Car, Truck, Bike etc will be derived from class Vehicle. And then we can have appropriate methods. Some of them are virtual. Vehicle class could be abstract having pure virtual methods and so on..." It was that easy. But right in front of them, very much at that time itself, under "do it now and let me see" pressure, I could not have thought of it all clearly and what I went on telling them was totally weird.
Thus, despite of designing complicated projects (along with their coding and testing) like high-performance server framework and Messaging app, all by my own, I still get rejected in multiple C++ interviews in this manner. In one of the interviews I tried to tell them to go through my GitHub repository and have look at my design and coding. But of no use. This is really extremely frustrating experience I am going through these days.
Please advise me and give me suggestions as to how can I go about it next time I face interview. Time is running fast and I cannot afford loosing interview opportunities just like that. Please help.