Senior Back-end Developer (.Net)

We are looking for a Senior Back-end Developer (.NET) to join our engineering team and play a key role in designing, developing, and evolving scalable, cloud-native backend systems. In this position, you will take ownership of critical platform components, contribute to architectural decisions, and help shape the technical direction of our products. You will work on multi-tenant, distributed systems, responsible for implementing new functionality, maintaining existing services, and continuously improving performance, reliability, and scalability. This role involves close collaboration with cross-functional teams, active participation in technical discussions, and mentoring of other engineers. Your work will directly impact core platform areas such as provisioning workflows, billing and invoicing engines, vendor synchronization services, and notification systems.

Key Responsibilities:

• Design, develop, and maintain high-quality backend services using modern .NET technologies.
• Take ownership of critical system components, including architecture, design, documentation, and long-term maintainability.
• Build and evolve multi-instance and multi-tenant architectures.
• Implement inter-service communication using Azure Service Bus and REST APIs.
• Develop and maintain scheduled background workers and asynchronous processing pipelines.
• Participate in system architecture discussions, propose improvements, and influence technical decision-making.
• Continuously improve code quality, performance, security, and system reliability.
• Perform code reviews, provide technical guidance, and mentor other engineers.
• Collaborate closely with QA and support teams to troubleshoot complex production issues and improve system stability.
• Actively contribute to improving development processes, engineering standards, and delivery practices.
• Participate in the full software development lifecycle: requirements analysis, estimation, design, development, testing, deployment, and maintenance.

Must-have:

• 5+ years of professional experience in back-end development using the .NET stack, with a strong focus on C# and modern .NET (6+).
• Strong hands-on experience in designing, developing, and maintaining high-performance, scalable, and reliable backend services.
• Proven experience with ASP.NET Web API and building RESTful APIs.
• Expert knowledge of MS SQL Server, including performance tuning, indexing strategies, query optimization, and data modeling.
• Advanced experience with Entity Framework, including performance optimization and complex data access scenarios.
• Solid understanding and practical application of SOLID principles, clean architecture, and modern software engineering best practices.
• Strong experience working with message-based architectures using Azure Service Bus (experience with RabbitMQ, Kafka, or Azure Queue Storage is a plus).
• Strong experience with Git-based version control workflows and collaborative development practices.
• Ability to design and implement robust, maintainable, and testable software solutions.
• Upper-intermediate or higher English communication skills, enabling effective collaboration in an international environment.

Nice to have :

• Hands-on experience with Azure Durable Functions or other serverless and workflow orchestration solutions.
• Experience designing and operating multi-tenant and multi-instance systems.
• Practical experience with microservices architecture and distributed systems.
• Knowledge and application of CQRS and event-driven architecture patterns.
• Experience building and maintaining CI/CD pipelines and automated deployment workflows.
• Familiarity with LeSS (Large Scale Scrum).
• Experience in B2B SaaS platforms, billing systems, provisioning engines, or integration-heavy environments.
• Strong automation mindset: ability to identify repetitive processes and design automated solutions.

What we offer:

• Remote-First Flexibility: Enjoy the freedom of a fully remote role, or choose to work from our Latvia office.
• Work with global Tech Leaders: Collaborate on solutions used by some of the biggest names in the industry, including Adobe, AWS, Cisco, Google, IBM, Microsoft, Lenovo, and Liquid. Your work will help shape how these companies deliver services across the globe.
• Skilled, International Team: Work alongside experienced professionals in a collaborative, multicultural environment. We value technical excellence, clear communication, and mutual support.
• Professional Development: Advance your skills with access to Microsoft certifications and continuous learning opportunities tailored to your role.
• Time to Recharge: Enjoy four weeks of paid vacation per year, plus paid public holidays.
• Referral Rewards: Help us grow our team - our employee referral program recognizes and rewards your contributions.

Join AppXite Platform Engineering team and work with a talented group of engineers building out next-generation technologies!

AppXite is a product software development company, based in Riga, Latvia. Our Platform is an AI-Ready Digital Marketplace, CPQ & Billing Platform for Telco, SaaS, Cloud, and AI services. It enables partners to build and monetize as-a-service offerings with flexible pricing models. The platform includes pre-built vendor and catalog integrations with major providers like Microsoft, Google, AWS, and Adobe. It supports various billing configurations, helping partners effectively manage and grow their businesses.