Project/Client: FintechDuration: 12 monthsRole Overview:We are looking for a Senior .NET Developer to join a fintech project delivering greenfield payment initiatives across Europe. This is a hands-on engineering role focused on building modern, compliant payment platforms from the ground up, requiring deep expertise in real-time and batch payment systems, banking standards, and Open Banking within regulated environments.Key Responsibilities:Develop and maintain backend payment processing services using C# / .NETImplement and process ISO 20022 and SWIFT MT/MX payment messagesIntegrate with bank APIs, real-time payment rails, and file-based channelsSupport the full payment lifecycle from initiation to clearing, settlement, and reconciliationEnsure security, compliance, error handling, and auditability of payment flowsCollaborate with engineering, product, and compliance teamsContribute to code reviews, testing, CI/CD, and technical documentationMust-Have Requirements:6+ years of hands-on experience with C# / .NET (Core / 6 / 7 / 8)Strong, practical experience with payment systems and banking integrationsAdvanced knowledge of ISO 20022, SEPA, and payment messaging standardsHands-on experience with SWIFT, FPS, BACS, CHAPS, TARGET2Proven experience with Open Banking and regulated payment environmentsExperience with REST, SOAP, SFTP, XML/JSON, message queues, and SQL ServerSecure coding practices and familiarity with DockerExcellent English communication skillsNice to Have:Experience with core banking systems or digital walletsKnowledge of cut-off times, clearing, and settlement processes