Senior Backend Developer (.NET) in the EU

DOU Polska; Województwo mazowieckie; Remote; PLN 264,000 - 441,000; Full time

Benefits offered by this job

Remote or hybrid work

Private health insurance

Sports compensation

Training portal access

Mentoring and adaptation program

Annual bonus up to 1000 EUR

Job summary

Andersen is hiring a Senior Backend Developer (.NET) for a EU-based project to build a modern digital insurance platform with secure, scalable APIs and seamless system integrations.

You will design .NET 8 microservices, implement Temporal workflows, integrate GoRules Zen, and collaborate on API contracts, tests, and cloud deployments. Remote or hybrid work options are supported. The role requires strong C#, EF Core, Docker, Azure, and clean architecture expertise, with intermediate+ English.

Qualifications

• 5+ years of commercial experience with C# / .NET
• Hands-on experience with .NET 8
• Experience with Temporal workflow orchestration
• Experience designing and developing microservices
• Strong understanding of Clean Architecture, SOLID principles, and layered architecture
• Knowledge of distributed systems and asynchronous processing
• Experience with Azure and EF Core
• Experience writing unit and integration tests
• Experience with Docker and containerized development
• Ability to learn new technologies quickly
• Intermediate+ English

Responsibilities

• Designing and building .NET 8 microservices – FastEndpoints, clean architecture (Domain / Application / Infrastructure / API layers)
• Implementing Temporal workflow orchestration – typed workflow and activity interfaces, cross-task-queue dispatch, signal/query patterns
• Building rules evaluation integrations with GoRules ZEN engine (GoRules.Zen NuGet, Rust FFI in-process)
• Developing platform capabilities – config registry, rules API, workflow gateway, payment and policy adapters
• Implementing cross-cutting concerns – Managed Identity service-to-service auth, Cerbos authorization integration, structured logging via Serilog/Anotar
• Writing and maintaining xUnit tests – FakeItEasy for mocking, Shouldly for assertions; integration tests against real dependencies (no mock DB)
• Collaborating with platform and domain teams on API contracts, OpenAPI specs, and shared NuGet libraries

Skills

C# / .NET

.NET 8

Temporal workflows

Microservices design

Azure

Entity Framework Core

Docker and containers

English (Intermediate+)

Tools

Azure

Docker

EF Core

GoRules Zen

Job description

Andersen is hiring a Senior Backend Developer (.NET) in the EU for a project developing a digital insurance platform and delivering secure, scalable APIs and seamless system integrations.

The customer

is a large international organization operating in the insurance and risk protection domain, providing a wide range of services for both individual and corporate clients. The customer has a strong global presence, delivers diversified insurance solutions across multiple lines of business, and is known for its mature operational model, financial stability, and well-established expertise in service delivery and claims management.

The project

is focused on developing and enhancing a modern digital insurance platform that supports the full insurance lifecycle, including quoting, policy issuance, payments, servicing, renewals, and claims. It provides scalable, secure, and reusable APIs and digital services, enabling seamless integration of insurance products across web, mobile, and partner ecosystems.

Responsibilities

• Designing and building .NET 8 microservices – FastEndpoints, clean architecture (Domain / Application / Infrastructure / API layers).
• Implementing Temporal workflow orchestration – typed workflow and activity interfaces, cross-task-queue dispatch, signal/query patterns.
• Building rules evaluation integrations with GoRules ZEN engine (GoRules.Zen NuGet, Rust FFI in-process).
• Developing platform capabilities – config registry, rules API, workflow gateway, payment and policy adapters.
• Implementing cross-cutting concerns – Managed Identity service-to-service auth, Cerbos authorization integration, structured logging via Serilog/Anotar.
• Writing and maintaining xUnit tests – FakeItEasy for mocking, Shouldly for assertions; integration tests against real dependencies (no mock DB).
• Collaborating with platform and domain teams on API contracts, OpenAPI specs, and shared NuGet libraries.

Must-haves

• Commercial experience with C# / .NET for 5+ years.
• Strong hands-on experience with .NET 8.
• Experience with Temporal workflow orchestration and Temporal .NET SDK.
• Experience designing and developing microservices.
• Strong understanding of Clean Architecture, SOLID principles, and layered architecture.
• Strong understanding of distributed systems and asynchronous processing.
• Experience with system design, transactions, concurrency, idempotency, and error handling.
• Strong hands-on experience with Azure.
• Strong experience with Entity Framework Core.
• Experience writing unit and integration tests.
• Experience with Docker and containerized development.
• Ability to independently and quickly learn new technologies and libraries.
• Willingness to study project-specific libraries before the technical interview.
• Level of English - Intermediate+ and above.

Nice-to-haves

• Experience with FastEndpoints.
• Experience with GoRules ZEN, JDM, and ZEN expressions.
• Experience with Cerbos.
• Experience with JSONata .NET.
• Experience with Azure Key Vault, Managed Identity, Blob Storage, and Application Insights.
• Experience with xUnit, FakeItEasy, and Shouldly.
• Experience with Podman / Podman Compose.
• Experience with ASP.NET Core Minimal APIs.
• Experience with Kafka and event-driven architecture.
• Experience with SOAP/WCF integrations.
• Experience with Result/Maybe patterns.

Reasons Why This Job Would Be Interesting To You

• Experience in teamwork with leaders in FinTech, Healthcare, Retail, Telecom, and others. Andersen cooperates with such businesses as Samsung, Siemens, Johnson & Johnson, BNP Paribas, Ryanair, Mercedes, TUI, Verivox, Allianz, T-Systems, etc.
• The opportunity to change the project and/or develop expertise in an interesting business domain.
• Job conditions - you can work both fully remotely and from the office or can choose a hybrid variant.
• Guarantee of professional, financial, and career growth! The company has introduced systems of mentoring and adaptation for each new employee.
• The opportunity to earn up to an additional 1,000 EUR per month, depending on the level of expertise, which will be included in the annual bonus, by participating in the company's activities.
• Access to the corporate training portal, where the entire knowledge base of the company is collected and which is constantly updated.
• Bright corporate life (parties / pizza days / PlayStation / fruits / coffee / snacks / movies).
• Certification compensation (AWS, PMP, etc).
• Referral program.
• Private health insurance and sports compensation, depending on the type of employment.

Your personal data is protected in accordance with GDPR regulations. Learn more: https://andersenlab.com/privacy-policy

https://andersenlab.com/privacy-policy/pl