Senior .NET Backend Engineer — REST APIs for SaaS (Hybrid)

Kallidus; Lisboa; Hybrid; EUR 55,000 - 90,000; Full time

Benefits offered by this job

27 days annual leave

Hybrid work model

Tech setup provided

Growth & development support

Enhanced family leave

Job summary

Kallidus is seeking a skilled .NET Developer to design, build and maintain scalable backend services and RESTful APIs for a global SaaS platform. You’ll work in an Agile team, collaborating with Product, QA, and Engineering to deliver high-quality software.

Remote-friendly with hybrid approach, you’ll contribute to architecture discussions, code reviews, and performance improvements while ensuring security and reliability across services.

Qualifications

• Commercial experience as a .NET Developer or similar.
• Strong RESTful API design and implementation experience.
• Excellent ASP.NET Core Web API knowledge.
• Relational DB design with SQL Server.
• Experience with API integrations and third-party services.
• Familiarity with cloud-native architectures and microservices.
• Understanding of HTTP, JSON, and modern web tech.
• Experience in Agile environments.

Responsibilities

• Design, develop, and maintain scalable .NET applications and services.
• Build high-performance RESTful APIs to support the SaaS platform.
• Collaborate with Product, QA, and Engineering to translate requirements into solutions.
• Contribute to architecture discussions and technical design decisions.
• Write clean, maintainable, testable code following best practices.
• Develop and maintain API integrations with internal and external systems.
• Support deployment, monitoring, and continuous improvement of apps.
• Troubleshoot production issues and optimise performance.
• Document code and architecture throughout the lifecycle.
• Ensure security, scalability, and reliability standards are met.

Skills

RESTful Web APIs

ASP.NET Core

(.NET)

C#

SQL Server

Azure

Docker

CI/CD

Agile

Microservices

API Gateways

Security Best Practices

Tools

Azure DevOps

Job description

Kallidus is seeking a skilled .NET Developer to design, build and maintain scalable backend services and RESTful APIs for a global SaaS platform. You’ll work in an Agile team, collaborating with Product, QA, and Engineering to deliver high-quality software.

Remote-friendly with hybrid approach, you’ll contribute to architecture discussions, code reviews, and performance improvements while ensuring security and reliability across services.