Senior Software Engineer (Java / .NET)

Senior Software Engineer (Java / .NET) Remote | Bulgaria | London Working Hours Our client, a leading U.S. investment management firm, is seeking an experienced Senior Software Engineer to join a highly collaborative engineering team responsible for developing and supporting business-critical applications. This is a full-time remote consulting opportunity for a senior, hands-on engineer who is comfortable working across both Java and C#/.NET environments. Fluent professional English is required, as you will communicate directly with U.S.- and international-based technical and business stakeholders. This position will operate on London business hours and is open to candidates located in Bulgaria. What You'll Do Design, develop, and maintain enterprise software applications using Java and C#/.NET. Build scalable APIs and backend services. Participate in architecture discussions, code reviews, and technical design. Collaborate closely with business stakeholders and fellow engineers in a distributed international environment. Troubleshoot production issues and continuously improve existing systems. Contribute to engineering best practices, automated testing, and software quality. What We're Looking For 7+ years of professional software engineering experience. Strong hands-on development experience with both Java/Spring Boot and C#/.NET. Ability to move comfortably between Java and .NET codebases. Experience developing and supporting enterprise applications. Experience with REST APIs and SQL databases. Cloud experience with AWS and/or Azure. Fluent professional English, both written and spoken. Comfortable communicating directly with technical and business stakeholders in English. Comfortable working full-time London business hours. Someone who enjoys being hands-on and deep in the code. Preferred Experience Banking, Financial Services, Investment Management, FinTech, or Payments. Microservices architecture. Docker and Kubernetes. CI/CD pipelines. Messaging technologies such as Kafka or RabbitMQ. Angular or React. Why Consider This Opportunity? 100% remote from Bulgaria. Work directly with a respected U.S.-based investment management firm. Initial 6-month consulting engagement with the potential for renewal. Modern enterprise technology environment. Collaborative international engineering culture. Meaningful technical challenges and business-critical applications. If you're an experienced engineer with strong Java and C#/.NET skills, fluent professional English, and are comfortable working London hours, we'd love to connect.