Senior Software Engineer – Backend (.NET) at 99x

, Western Province, Sri Lanka -

Full Time

Start Date

Immediate

Expiry Date

21 Sep, 26

Salary

0.0

Posted On

23 Jun, 26

Experience

5 year(s) or above

Remote Job

Yes

Telecommute

Yes

Sponsor Visa

Skills

C#, .NET Core, Web API, SDK Development, SQL Server, Docker, Git, xUnit, Backend Architecture, CI/CD, AI Tools, Elasticsearch, Kubernetes, Ansible, C/C++, Azure DevOps

Industry

IT Services and IT Consulting

Description

We are looking for a Senior Software Engineer to join our backend engineering team and work on a range of platform and product initiatives, including backend services, SDKs, APIs, search technologies, and enterprise applications. You will collaborate closely with Product Managers, Architects, and Engineers in Norway, contributing to solution design, implementation, testing, and delivery. This role requires strong technical expertise, ownership, and the ability to communicate effectively in a distributed international team. Responsibilities Design, develop, and maintain backend applications using C# and .NET. Build and enhance Web APIs, SDKs, reusable libraries, and platform components. Write unit and integration tests to ensure high software quality. Participate in architecture discussions, code reviews, and technical design sessions. Optimize application performance, scalability, and reliability. Contribute to CI/CD pipelines, deployment automation, and operational improvements. Demonstrate completed solutions and communicate technical decisions effectively to stakeholders. Requirements 4+ years of software development experience with C# and .NET Core / .NET (SDK 8+). Experience developing and maintaining Web APIs and SDKs. Strong understanding of software design principles and backend architecture. Experience with SQL Server (2018+), Docker, and Git. Experience with unit and integration testing using xUnit. Strong problem-solving and analytical skills. Ability to explain technical concepts and present solutions clearly. Comfortable working with AI tools and AI agents in a fast-paced development environment. Experience automating workflows using AI is an added advantage. Experience working with distributed teams and remote stakeholders. Self-driven, collaborative, and committed to delivering high-quality software. Strong verbal and written English communication skills. Nice to have Experience with plugin-based or extensible application architectures. Working knowledge of C/C++, including memory and buffer management. Experience with Azure DevOps and CI/CD pipelines. Familiarity with Elasticsearch. Experience with AST/Parse Tree-based code generation. Understanding of programming language grammars and compiler design. Experience with Kubernetes (K8s) and Ansible.

Responsibilities

Design, develop, and maintain backend applications, Web APIs, and SDKs using C# and .NET. Collaborate with international teams to optimize application performance, scalability, and reliability through CI/CD pipelines.