Principal Full Stack .NET Engineer

UBB was established in 1992 through the merger of 22 Bulgarian regional commercial banks as the first and largest in terms of scale consolidation project in the Bulgarian banking sector. Since 2017,  the Bank has been part of the Belgian bank-assurance group КВС, currently the largest financial group in Bulgaria.

While invariably standing by our corporate values, we want to be the reference in the bank business through client-centricity in all our activities. We aim at achieving sustainable and profitable growth by fulfillment of our role in society.

UBB is seeking a talented and dynamic Principal Full? Stack. NET Engineer to join our IT Delivery team

 
Requirements:

Backend (. NET)

• 7+ years of hands? on professional experience in. NET (. NET 9. 0) / C# backend development, with full? stack exposure
• Proven experience designing and evolving ASP. NET Core–based architectures following microservices and clean architecture principles
• Strong hands? on experience with HTTP integrations and consumption of external and internal services
• Deep expertise in API? first design, using OpenAPI / NSwag for system? to? system integrations
• Experience designing and maintaining enterprise? grade infrastructure libraries, including logging, exception handling, and custom middleware
• Strong focus on security? and compliance? aware development, including sensitive data handling, redaction, and secure API design
• Solid understanding of resilience and reliability patterns such as retries, timeouts, circuit breakers, and graceful degradation

Frontend (Angular)

• Strong practical experience with Angular and TypeScript in large? scale frontend applications
• Proven ability to design modular, scalable, and maintainable frontend architectures
• Solid knowledge of JavaScript, XML/JSON, XSLT, and frontend integration with RESTful APIs
• Experience working with shared UI components, application state management, and frontend best practices
• Ability to ensure frontend performance, usability, and long? term maintainability

DevOps & Delivery

• Strong expertise in DevOps practices, including CI/CD pipeline design, build automation, and release management
• Hands? on experience integrating applications into automated build, test, and deployment pipelines
• Solid understanding of environment configuration, deployment strategies, and release orchestration
• Experience collaborating with platform, infrastructure, or SRE teams to improve deployment reliability, scalability, and observability
• Familiarity with monitoring, logging, and alerting concepts in production systems

Data, Quality & Leadership

• Solid knowledge of Microsoft SQL Server and data? driven application development
• Ability to write high? quality, maintainable, testable, and production? ready code
• Excellent analytical thinking, communication, and technical decision? making skills
• Proven ability to solve complex problems, lead technical discussions, and guide teams through challenging scenarios
• Fluent English, written and spoken
• University degree in Computer Science, Informatics, Engineering, Mathematics, or a related field
   
  

Nice to Have:

• Strong experience in the financial, banking, or fintech domain
• Proven background working on large? scale enterprise systems
• Hands? on experience with CI/CD pipelines, DevOps practices, and release automation
• Experience working in Agile / Scrum environments
• Exposure to cloud platforms and distributed system operations
   
  

Responsibilities:

Technical Leadership & Full? Stack Delivery

• Lead and contribute to the end? to? end lifecycle (design, development, and maintenance) of a new enterprise? grade online solution, delivering state? of? the? art backend services and APIs using. NET and ASP. NET Core, along with modern frontend components developed in Angular
• Define and evolve technical architecture and standards across backend and frontend layers
• Design, develop, and maintain high? performance, secure backend services and APIs
• Drive the development of scalable, user? friendly frontend applications, ensuring seamless integration with backend APIs
• Contribute to and continuously improve microservice? based architectures, aligned with clean architecture principles for a modern online banking solution

New Functionalities & Platform Capabilities

• Lead the design and implementation of new core functionalities that extend platform capabilities and support evolving business requirements
• Drive the integration of advanced authorization, access? control, or platform services (e. g. , SpiceDB or similar technologies) into the existing system landscape
• Evaluate, prototype, and introduce new technologies or third? party components, ensuring alignment with security, scalability, and enterprise architecture standards
• Define integration patterns, APIs, and data models required to support new platform features
• Ensure newly introduced functionalities are secure, compliant, well? documented, and production? ready
• Collaborate with architects, security teams, and business stakeholders to ensure successful adoption and long? term maintainability of new capabilities

Integration, Security & Reliability

• Own and maintain reliable integrations with internal and external systems
• Lead API design, versioning, documentation, and lifecycle management using OpenAPI / NSwag
• Ensure secure, compliant, and resilient implementations, applying best practices for data protection and fault tolerance
• Promote operability, observability, and reliability across services

DevOps & Engineering Excellence

• Drive and contribute to DevOps practices, including CI/CD pipeline design, build automation, and deployment strategies
• Collaborate with DevOps and infrastructure teams to improve deployment reliability, scalability, and monitoring
• Advocate for shift? left quality, test automation, and continuous delivery principles
• Identify and implement engineering improvements that increase delivery speed, quality, and system stability