To bid on a public tender in Romania, you register your company in SEAP (e-licitatie.ro) with a qualified digital certificate, find a notice that fits your trade, read the tender documentation to check the qualification requirements, prepare the DUAE and your technical and financial offer, and submit everything electronically before the deadline.
The DUAE (Document Unic de Achiziție European, in English ESPD) is a self-declaration in which a bidder states that it meets the exclusion and qualification criteria of a tender.
Construction tenders in Romania typically ask for four kinds of proof: that the company may carry out the activity, that it has enough financial standing (a minimum turnover), that it has done similar works before, and that it has the people, equipment and certificates for the job.
First-time bidders on Romanian tenders most often lose by choosing tenders they cannot qualify for, missing a requirement hidden in the data sheet, leaving submission to the last hour, or declaring things in the DUAE that they cannot prove.