.NET Backend Developer

October 26, 2026

Office

Middle

Oeiras, Portugal

Indeed

Keep in mind

Another language required
Portuguese
Office-only work

Also worth knowing

English is required

Description

A technology company with offices in Portugal, Angola and Mozambique builds software and hardware solutions for the financial and banking sector. The internal team is growing and looking for a .NET Backend Developer to develop and maintain the middleware layer that exposes kiosk services and integrates with client banks' systems. The work covers modular ASP.NET Core APIs, connectors to core banking and other external systems over REST and SOAP, automated tests, code reviews and CI/CD pipelines in Azure DevOps. The position is based in Oeiras, Portugal, with a flexible on-site schedule and a full-time employment contract.

Responsibilities

Develop and maintain middleware APIs and business flows in .NET (ASP.NET Core), in a modular and reusable way across clients
Build and maintain connectors to external bank systems (core banking, SMS, tax authorities and others) via REST and SOAP
Ensure the solution is configurable per client, distinguishing what is global, configurable and client-specific
Write automated tests, perform code reviews and keep middleware technical documentation up to date
Work in Azure DevOps: work items, Git repositories, CI/CD pipelines and Scrum ceremonies
Support incident diagnosis in clients' QA and production environments (logs, SQL Server, connectivity)
Collaborate with teams of the other product layers, Solution Architecture and project and field teams

Requirements

3 to 5 years of backend development experience with C# and .NET (ASP.NET Core, .NET 8 or higher, ideally .NET 10)
Experience designing and consuming REST APIs; knowledge of SOAP/WCF services
Experience with SQL Server: data modeling, queries and performance analysis
Engineering best practices: unit and integration tests, SOLID principles, structured logging and error handling
Git and work with CI/CD pipelines (ideally Azure DevOps)
Experience in agile teams (Scrum or Kanban)
Clear communication and team spirit, with openness to give and receive feedback
Attention to detail and strong problem-solving ability
Ability to stay focused under pressure, learning from each challenge and adjusting the approach when needed
Fluent Portuguese; technical English for reading and writing
Nice to have: experience in the banking or financial sector (core banking, payments, KYC, reconciliation)
Nice to have: experience with .NET Framework 4.x and maintenance of legacy applications
Nice to have: experience in Azure cloud environments
Nice to have: development in a Windows environment: Windows services, IIS, PowerShell
Nice to have: integration with physical devices or third-party SDKs (ATM, POS, kiosks or similar)
Nice to have: stateful transactional flows and resilience patterns (retries, idempotency, failure recovery)