Senior .NET Developer
We are seeking a Senior .NET Developer who will take a lead role in crafting and delivering scalable software solutions. Develop high-performance applications, craft architectural strategies, mentor implementation of standards, provide team mentorship. Within your responsibilities, you will partner closely with product coordinators, architects, and other teams to convert business requirements into technical blueprints, ensuring secure, efficient, and forward-thinking solutions. As a senior member of the team, you will be trusted to own sophisticated initiatives end-to-end, provide technical leadership, and help evolve our engineering culture
This is a hybrid role, and it requires 3 days in our office in Sofia. The office location is 1 Boris Nikolov - Mokata Str, 1407 Sofia. Easily found next to Paradise mall – Office X , building 3, floor 5
What You’ll Be Doing
Software Development & Engineering Excellence
● Define and carry out coding standards, guide architectural decisions, and champion standards
● Lead the design, development, and enhancement of scalable .NET applications using C#
● Deliver high-quality, reusable, maintainable code aligned with modern engineering standards
● Integrate third-party APIs with strong focus on reliability, error handling, and data integrity
● Fix and resolve sophisticated bugs, performance issues, and edge-case behaviours across environments
● Guide junior and mid-level developers by providing feedback on their code, offering technical advice, and aiding in Performance, Security & Data Architecture
● Own performance, scalability, and resilience strategies across distributed systems
● Promote the use of cloud-native and microservices-based architectures where relevant
● Ensure consistent application of security guidelines and data protection principles
● Design and maintain secure, efficient, scalable data storage solutions Teamwork & Agile Delivery
● Partner with product managers and QA to translate business objectives into technical strategies
● Lead and actively chip in to Agile ceremonies (sprint planning, stand-ups, reviews, retrospectives)
● Coordinate architectural discussions, user documentation, and ensure cross-team alignment DevOps, Tooling & Innovation
● Own and evolve CI/CD workflows using GitLab, focusing on automation, reliability, and delivery efficiency
● Evaluate, recommend, and drive adoption of new tools, frameworks, and practices that support long-term technical strategy
● Promote continuous improvement by modernising codebases, development practices, and release processes Communication & Accountability
● Act as a conscientious technical consultant for collaborators, aligning architecture and delivery wiinterpersonalnal goals
● Own delivery commitments and lead priorities effectively in a fast-moving environment
● Take initiative on sophisticated projects while adapting to evolving priorities and business needs. What We're Looking For
● Expert-level proficiency in .NET 6+ / C# and the .NET Framework, with deep experience in ASP.NET MVC, Web API, and Entity Framework Core (migrations, concurrency handling, query tuning). Strong skills in async programming, performance optimization, and API design.
● Proven track record in system architecture, distributed systems, and cloud-native/event-driven designs. Deep knowledge of DDD, CQRS, Mediator, clean architecture, and microservices.
● Sophisticated hands-on experience with MS SQL Server 2017+, PostgreSQL, and/or MySQL, including schema design, query performance tuning, and scalability. Practical experience with NoSQL (MongoDB) and distributed caching (Redis).
● Strong experience with message brokers (RabbitMQ or similar) in microservices environments; skilled in system integrations and building scalable RESTful APIs (gRPC a plus).
● Main focus on unit and integration testing; experienced with mocking frameworks, automated build pipelines, and designing effective testing strategies (performance and security testing as a plus).
● Hands-on with Docker and Kubernetes (production-grade deployments). Experience with GCP or AWS services preferred.
● Implements security protocols at scale; skilled in networking concepts, observability (logging, metrics, tracing, OpenTelemetry), and fixing issues in distributed environments.
● Strong grasp of SOLID principles, clean code practices, and making sure coding standards across teams.
● Excellent communicator with the ability to influence architectural decisions, align technical strategy with business goals, and lead cross-team discussions. ● Consistent record to mentor and coach developers, review code and designs, and drive continuous improvement across engineering teams.
● Analytical problem solver, fluent in written and spoken English, with a track record of delivering scalable, high-quality solutions.
