A year ago the company where I work founded a startup to develop an IoT device, and since my hiring (August 2019 as a Junior Full Stack Developer, I am 19) I have been working on its mobile app as the only Android Developer, but still employed in the "big company" (not so big actually because the IT department consists of 12 people).
When I arrived there I didn't know Android Programming at all, but in these months I have learnt quite fast and my boss keeps saying that he didn't expect this "quality" from me because I can handle all the stuff that my company needs. I am very happy about this of course and I enjoy a lot what I am doing. I am also very interested about this new project and I keep asking question/participating during the meetings, etc...
The problem came about a month ago, when I was talking with some coworkers in the startup's office (we share a big apartment divided in two by a corridor) and the Firmware Developer asked me: "If it were possible, would you join us as a F.Dev?" I sincerely answered that I loved the project and that I would enjoy working with them but I was happy to work as Android Dev, not to mention the fact that I was (and still I am) the only one, so I couldn't leave "the boat". After this conversation in the following weeks they sometimes repeated (even if in a kidding manner) the question and I almost always answered that I couldn't clone myself, that I like both the jobs, etc.. This situation continued until last week, when the CTO and the F.Dev. of the startup called me in a short meeting and asked me seriously if I'd like to join them. They told me they would be very happy, that a Jr. Firmware Dev is strongly needed and they are sure I would be awesome, etc... Of course I was flattered about all that, and I said that in the followings days I would think about it.
After many days yesterday I made the decision and I thought that it was the time to share all of this to my supervisor, the IT manager of my company. Shortly, he said that he knew that already because he listened many times when the startup's workers were joking with me. He told me he was glad I told him spontaneously, and he was fully conscious about my good intentions but that situation, if not handled correctly, was dangerous for our department. Maybe some executive could think that he was not controlling the division, or that the workers are escaping his department, etc... I acknowledged all his reasons and I felt quite ashamed because I wasn't thinking my genuine and true interest for that project could cause such a large amount of problems. He told me also that I am important for this division and he is thinking to hire another Jr. to work with me instead of a Senior, to allow me to work along and somehow teach him. The discussion finished and my boss told me that I was free to choose and the decision is mine, of course he needs to know what I will decide in order to search the correct profiles for the company.
Before that talk I was almost sure that I would have liked to change position to learn new things and to help develop a project I am very proud of, but now I am quite scared about the consequences. What would you do if you were in my shoes? I like both jobs, but if I remain here I would have a primary position (and I hope so that will bring to a raise, since I am the responsible for the app, and I think that this responsibility should not belong to a Jr. Dev who also in the future months will have to teach other Jrs.) while in the other side I would learn many new things I'll love to do , and this makes me feel kinda sad, because I am feeling like I am wasting a nice opportunity.
Thanks for your attention and your help, sorry if I have made many mistakes with verbs and grammar.
Guys, thank you kindly for all your wholesome support and help. I have understood that I have nothing to be ashamed of and the final decision is up to me. Joining the startup would make me learn a lot of new things that I'll love and also it wouldn't mean that I have to stop doing apps, maybe in my free time for fun. The only problem (which of course I have to solve on my own) is: should I make this change or should I keep my (maybe) future lead position in Android (with the following raises)? Thanks again for your time and sorry for the long question:)