Backend Developer (Remote, UK)

About the role

Hyalli is looking for a Backend Developer to design, build, and maintain the backend infrastructure powering its web and mobile platforms. You will work closely with the lead developer and founding team, taking ownership of technical decisions in a remote‑first environment.

Key responsibilities

• Design and develop backend services for web and mobile applications.
• Build secure, well‑documented RESTful APIs consumed by frontend and mobile clients.
• Model and manage data, ensuring privacy compliance and GDPR adherence.
• Contribute to decisions on technology stack, architecture, infrastructure, and deployment.
• Write clean, tested, and maintainable code.
• Iterate quickly based on real user feedback.

Required profile

• Proven experience with server‑side languages such as C#, Python, Java, or Node.js.
• Strong knowledge of RESTful API development (e.g., ASP.NET Web API or equivalent).
• Solid understanding of database design and ORM tools (SQL, T‑SQL, PL/SQL, Entity Framework, etc.).
• Working knowledge of GDPR‑compliant frameworks and data‑protection principles.
• Experience working in Agile development environments.
• Ability to write code you would be happy to revisit months later.

Required skills

• C#
• Python
• Java
• Node.js
• RESTful API development
• ASP.NET Web API (or equivalent)
• SQL / T‑SQL / PL/SQL
• Entity Framework or similar ORM
• GDPR compliance
• Agile development

What we offer

• Fully funded startup with a clear runway.
• Early‑stage equity opportunity.
• Real ownership and influence over technical direction.
• Remote‑first work model with flexibility.
• Product addressing a strong market need with early traction.
• Small, focused team with minimal bureaucracy.