Senior Backend Developer - C# and .NET 10 (Remote, Contractual), PK [AS239]

About Smart Working At Smart Working, we believe your job should not only look right on paper but also feel right every day. This isn’t just another remote opportunity - it’s about finding where you truly belong, no matter where you are. From day one, you’re welcomed into a genuine community that values your growth and well-being.

Our mission is simple: to break down geographic barriers and connect skilled professionals with outstanding global teams and products for full-time, long-term roles. We help you discover meaningful work with teams that invest in your success, where you’re empowered to grow personally and professionally.

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About the Role We are looking for a Senior Backend Developer to join a collaborative product engineering team building and scaling a modern accommodation booking platform used by corporate travellers worldwide.

This role is focused on developing and evolving scalable backend services and APIs using C# and .NET 10, helping power critical booking, quoting, integration, and search functionality across the platform.

You will work closely with Product Managers, QA Engineers, Data teams, and other Engineers to deliver reliable, maintainable, and high-performing backend systems. The role involves a strong focus on API integrations, observability, CI/CD, and backend reliability in a fast-paced product environment.   The team is currently focused on scaling and enhancing an internal accommodation booking engine, including: Accommodation search optimisation and advanced filtering AI-enhanced quoting and booking experiences Real-time integrations with third-party systems for booking management and synchronisation Platform scalability, observability, and reliability improvements This is a collaborative, backend-focused role suited to someone who enjoys solving complex integration and API challenges while contributing to engineering quality and platform evolution.

Responsibilities Design, develop, and maintain scalable backend services and APIs using C# and .NET 10 Build and maintain secure, reliable integrations with third-party systems and external APIs Define and implement resilient and fault-tolerant API communication patterns Troubleshoot and resolve complex backend and API issues, including connectivity and data consistency problems Ensure systems are observability-first through effective logging, metrics, monitoring, and alerting Create and maintain clear API integration documentation for internal and external stakeholders Collaborate closely with Product Managers, QA Engineers, Designers, and Data teams to deliver high-quality features Champion engineering best practices across testing, CI/CD, secure coding, and maintainability Mentor junior developers and contribute to overall engineering excellence Support ongoing platform scalability, integration, and performance improvement initiatives Contribute to the evolution of the company’s API platform and backend architecture Requirements Strong proficiency in C# and .NET 10, with experience building scalable and maintainable backend systems Strong experience designing, developing, and maintaining production APIs and backend services Experience diagnosing and resolving complex backend and API issues Experience working with CI/CD pipelines and deployment automation Strong understanding of API design, backend reliability, and maintainable system architecture Strong interpersonal and collaboration skills across cross-functional teams Experience writing clear and maintainable API integration documentation Pragmatic problem-solving mindset with strong attention to reliability and simplicity Commitment to delivering high-quality, performant, and supportable solutions Ability to work effectively in a collaborative, fast-moving engineering environment Nice to Have Experience with Azure Functions and serverless architectures Experience working with multi-tenant or multi-organisation systems at scale Familiarity with multicurrency implementations and internationalisation (i18n) Familiarity with OpenAPI 3.0 / 3.1 standards Experience using AI-assisted development tools such as Claude Code Knowledge of Infrastructure-as-Code tools such as Terraform Previous experience working on booking, marketplace, or travel-related platforms