Senior Back-End Developer – .NET / C# -High Growth SaaS

Overview

As a Senior Back-End Developer in a fast-growing fintech, you will own the design and delivery of C#/.NET microservices that power payment and FX services. You’ll shape architecture, engineering standards, and CI/CD practices while collaborating with DevOps, Product, and Operations. You work with PostgreSQL, Redis, Kubernetes/GKE, and Google Cloud to build secure, scalable systems. This is a hands-on role with leadership responsibilities, including code reviews and mentoring, within a team that values autonomy and technical excellence. The opportunity offers hybrid work in London and a senior seat at the table to influence critical platform decisions.

Pay / Benefits

• Hybrid working
• 25 days holiday + bank holidays
• Senior seat at the table

Responsibilities

• Build and maintain C#/.NET microservices
• Design APIs, integrations and data models
• Develop secure, scalable payment and FX services
• Work with PostgreSQL, Redis and Kubernetes/GKE
• Improve CI/CD, testing, observability and reliability
• Lead code reviews and mentor other developers
• Collaborate with DevOps, Product and Operations

Key requirements

• Strong commercial C#/.NET experience
• Microservices and REST API expertise
• Strong PostgreSQL and Redis knowledge
• Experience with Kubernetes / Docker / Cloud
• Strong testing and CI/CD background
• Technical leadership or mentoring experience
• Fintech/payments experience highly advantageous

• leadership or mentoring experience
• cross-functional collaboration
• problem-solving and initiative
• C#/.NET
• Microservices
• REST API

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