One Week Experience interview questions

worst experience ever. Very unprofessional . The interview lasts about 2 months. After first phone interview , they gave me a coding challenge (a project to complete) . After completing that another skype interview in where they gave me feedback they are very pleased and to come to their office to work for 1 day as the last step. I went to Berlin (though travel cost not imbursed) and worked with them 1 day. At the following day they sent me an email and offer me the job and told me that when their CEO come to office they will send me the contract paper. But they did not send me the contract paper , I wrote them email couple of times but no reply. After 1 month they replied and told me they can not send me the contract paper because for the project they want to hire me is longer active, which is pretty lame. They should have courage and professionalism to say whether they will hire or not at the very first day. Not hanging people 2 months. They totally waste my time and effort