Senior Software Engineer C#

Q-Tech; Barcelona; Hybride; EUR 60 000 - 75 000; Plein temps

Avantages offerts par ce poste

Hybrid model (1–2 days) in Barcelona

Résumé du poste

Q-tech is seeking aSenior Backend Engineer to advance their core platform for fintech clients. You’ll design and build backend services in C# / .NET, with strong focus on reliability, performance, and scalable architectures.

The role blends cloud and on‑prem work in Azure, IaC, and DevOps, and requires ownership to lead technical work without people management. Hybrid work from Barcelona with a modern office.

Qualifications

• 7+ years of experience as a Backend Engineer.
• Deep expertise in C#/.NET, SQL, and distributed architectures.
• Solid hands-on experience with Microsoft Azure and IaC in production (mandatory).
• Background in regulated, audited, compliance-driven or banking environments.
• Hands-on experience with Docker, performance tuning, and advanced troubleshooting.
• Strong ownership mindset and ability to lead technically without a people-management role.
• Comfortable working in hybrid cloud/on-prem environments.
• High level of English is essential.

Responsabilités

• Design and implement backend services in C# / .NET (ASP.NET Core) with a focus on reliability, scalability, and best engineering practices.
• Define versioned and stable APIs following schema-first models to ensure long-term compatibility and traceability.
• Design and maintain data models, audit models, and key event-driven flows for reporting and regulatory compliance.
• Apply critical backend patterns and engineering standards.
• Contribute to distributed systems with asynchronous processing and messaging.
• Work closely with DevOps to ensure consistent and reproducible environments.
• Participate in the design and maintenance of Azure infrastructure using Infrastructure as Code.
• Provide L3 support for on-prem banking environments (root-cause analysis, hotfixes, reproducibility).
• Optimize SQL performance, diagnose queries, read execution plans, and propose performance improvements.
• Collaborate closely with QA, Security, DevOps, and Data teams to ensure a robust and auditable product.

Connaissances

C# / .NET

SQL

Azure

Docker

IaC

Distributed systems

English

Outils

Azure Functions

Azure Service Bus

Kafka

RabbitMQ

Description du poste

Senior Backend Engineer – .NET / Azure | Fintech B2B

At Q-tech, we’re partnering with a well‑established fintech company that develops advanced banking‑connectivity and cash‑management solutions for large enterprises and financial institutions across more than 15 countries. We are currently looking for a Senior Backend Engineer with a strong ownership mindset to drive the evolution of their core platform.

The product is B2B, highly critical, fully audited, and directly connected to international banks. They are looking for someone who combines solid .NET backend expertise with real‑world experience in Azure, DevOps, and Infrastructure as Code, and who is comfortable working in hybrid environments (cloud + on‑prem infrastructures for banking clients).

What you’ll do

• Design and implement backend services in C# / .NET (ASP.NET Core) with a focus on reliability, scalability, and best engineering practices.
• Define versioned and stable APIs following schema‑first models to ensure long‑term compatibility and traceability.
• Design and maintain data models, audit models, and key event‑driven flows for reporting and regulatory compliance.
• Apply critical backend patterns and engineering standards.
• Contribute to distributed systems with asynchronous processing and messaging.
• Work closely with DevOps to ensure consistent and reproducible environments.
• Participate in the design and maintenance of Azure infrastructure using Infrastructure as Code.
• Provide L3 support for on‑prem banking environments (root‑cause analysis, hotfixes, reproducibility).
• Optimize SQL performance, diagnose queries, read execution plans, and propose performance improvements.
• Collaborate closely with QA, Security, DevOps, and Data teams to ensure a robust and auditable product.

What they’re looking for

• 7+ years of experience as a Backend Engineer.
• Deep expertise in C#/.NET, SQL, and distributed architectures.
• Solid hands‑on experience with Microsoft Azure and IaC in production (mandatory).
• Background in regulated, audited, compliance‑driven or banking environments.
• Hands‑on experience with Docker, performance tuning, and advanced troubleshooting.
• Strong ownership mindset and ability to lead technically without a people‑management role.
• Comfortable working in hybrid cloud/on‑prem environments.
• High level of English is essential.

Nice to have

• Previous experience in fintech, payments, treasury systems, or banking connectivity.
• TDD / contract testing at scale.
• Experience with messaging/queueing systems (Azure Service Bus, RabbitMQ, Kafka).
• Familiarity with Azure Functions and serverless architectures.
• Experience in SaaS B2B or high‑throughput platforms.

Tech stack

C# / .NET (ASP.NET Core), SQL, Azure, IaC, Docker, Azure Functions, Azure Service Bus, messaging patterns, distributed systems, monitoring & observability.

What’s offered

• Permanent contract.
• Salary: €60,000 – €75,000, depending on experience.
• Hybrid model (1/2 days) in Barcelona: flexibility + modern office.
• Mission‑critical B2B product with real impact on major corporations and international banks.
• Senior, high‑standards engineering team with a strong culture of best practices.
• Stable environment with a solid roadmap and architectural responsibilities from day one.verano, y ofrecemos seguro médico.