iMATCHATIVE Software Developer interview questions

Was contacted by a recruiter at iMatchative. Had technical interview with one of their engineers. Questions were designing and complexities related. Went well, got called for an onsite and scheduled it. Spoke to 4 people including a lunch interview. All along the process they never mentioned that they were looking for a candidate with a specific technology expertise. I was completely transparent about my abilities and made sure they knew about it before proceeding. Interview questions were okay and I did pretty well and was even acknowledged about it. After the interview, I was told that the feedback was really positive and that I would be a good fit and salary negotiations were on the table. I am not sure about what happened that they changed their mind and decided they needed someone with specific technology expertise. It was not a good experience especially after being very explicit about myself and hoping for the same transparency from them. Did not end up getting an offer.