I have been contacted by Collabera several times for IT contracts with Wells Fargo and United Health Care. Both times, I was strung along for weeks. The first time was with Wells Fargo, and I did finally receive a job offer that vaporized several weeks later. The second time was for a job at United Health Care. First it was an "urgent requirement" then I found out from several colleagues that they have been strung along for months about the same "several positions" that the hiring manager was supposedly "scheduling interviews" for, and they were never interviewed, yet like myself told that their resume was still "under consideration" by the hiring manager. After several weeks of this nonsense, I told them I wasn't wasting anymore time with dealing with recruiters for a job that doesn't exist.
