Senior Full-Stack API Engineer (.NET / React)

Our client is a US-based enterprise veterinary technology company building large-scale platforms that support diagnostic workflows for veterinary practices. Their platform processes high volumes of orders and results from external PIMS(Practice Information Management Systems) and third-party systems and is undergoing an ongoing evolution from legacy services to cloud-native architectures.

We are looking for a Senior Full-Stack API Engineer to join an existing team. You will work on cloud-hosted services that prioritize reliability, scalability, and zero-downtime migration, contributing to systems used daily by veterinary professionals across the US.

This role suits an engineer who is comfortable working in hybrid environments, modernizing legacy systems, and designing robust APIs that integrate with multiple external systems., * Design, build, and maintain C#/.NET-based APIs

• Develop and integrate frontend components using React
• Work with Azure Functions and cloud services in a hybrid architecture
• Design and optimize relational database solutions (Azure SQL / Oracle)
• Support zero-downtime migrations from legacy to cloud services
• Implement reliable data flows between gateways, services, and external systems
• Collaborate within an established team structure and existing workstreams

Do you have experience in Scalability?, Project technology stack: C# / .NET (APIs), React (frontend), Azure (Functions, Service Bus, Azure SQL), Relational databases (Azure SQL, Oracle), Event-driven and REST-based architectures

Workload: 100% (Full-time) on B2B

Candidate location: EU / EEA (remote, reasonable overlap with US time zones)

Language: English C1, * Strong experience with C# / .NET and API development

• Solid experience with React and modern frontend integration
• Experience with Azure cloud services (Functions, Service Bus, Azure SQL)
• Strong understanding of relational databases and data replication
• Experience with REST-based and event-driven architectures
• Familiarity with system reliability, scalability, and operational simplicity
• Comfortable working in large, distributed engineering teams

Nice to Have:

• Experience in veterinary, healthcare, or regulated industries
• Exposure to legacy-to-cloud migration projects
• Experience with observability tools (Application Insights, Datadog)
• Experience with queue-based messaging systems

Other:

Abilities to learn new things and not be afraid to ask questions are a must. Direct communication with the end client, so English skills should be on a sufficient level.