Senior Backend Developer

GönderAL Payment Services; Kâğıthane; On-site; TRY 300,000 - 540,000; Full time

Job summary

GönderAL Payment Services is seeking a senior backend engineer to design and build scalable services in a microservice architecture using C# and ASP.NET Core. You will work across SQL and NoSQL databases, optimize performance, and mentor junior developers in a fast-paced fintech environment.

You'll implement domain-driven design concepts, CQRS, and event sourcing where appropriate, shape API design, and contribute to an AI-first development approach.

Qualifications

• 5+ years of professional backend software development experience.
• Hands-on experience with .NET / C# (ASP.NET Core, .NET 6/7/8).
• Production experience with microservice architecture and inter-service communication (gRPC, REST, message brokers).
• Strong understanding of SOLID principles and Clean Architecture.
• Advanced SQL/NoSQL querying and schema design knowledge.
• Experience with event-driven architectures (RabbitMQ, Kafka, or Azure Service Bus).
• Experience with containerization using Docker and Kubernetes.
• Proficiency in Git-based workflows and agile teams.

Responsibilities

• Design and develop high-scale backend systems using microservice architecture.
• Build enterprise-grade APIs and services with the .NET (C#) ecosystem.
• Embrace an AI-first development approach and use AI tools to improve productivity.
• Work with SQL and NoSQL databases (PostgreSQL, MSSQL, MongoDB, Redis, Elasticsearch).
• Apply DDD, CQRS, and Event Sourcing where appropriate.
• Lead code reviews, define technical standards, and drive adoption across the team.
• Identify performance bottlenecks and optimize them.
• Mentor junior and mid-level developers; create technical docs.

Skills

.NET/C# backend

ASP.NET Core

Microservices

SQL & NoSQL

DDD/CQRS

Event Sourcing

Docker/Kubernetes

Messaging (RabbitMQ/Kafka/ASB)

Git & Code Review

Agile (Scrum/Kanban)

Tools

PostgreSQL

MSSQL

MongoDB

Redis

Elasticsearch

RabbitMQ

Kafka

Azure Service Bus

Docker

Kubernetes

Job description

GönderAL is a financial technology company focused on building secure and scalable digital payment platforms. We design systems that support real-time transactions, robust infrastructure, and user-friendly interfaces tailored for modern financial operations. We operate in a dynamic, collaborative environment focused on secure, reliable, and customer-centered financial services.

For us, impact is the driver of our work. We value ownership, practical problem-solving, and teamwork to deliver meaningful solutions for our customers and partners.

Responsibilities

• Design and develop high-scale backend systems using microservice architecture
• Build enterprise-grade APIs and services with the .NET (C#) ecosystem
• Embrace an AI-first development approach and actively use AI tools to improve engineering productivity and delivery quality
• Work effectively with both SQL (PostgreSQL, MSSQL) and NoSQL (MongoDB, Redis, Elasticsearch) databases
• Apply Domain-Driven Design (DDD), CQRS, and Event Sourcing concepts in real-world projects where appropriate
• Lead code review processes, define technical standards, and drive their adoption across the team
• Identify performance bottlenecks and optimize them systematically
• Mentor junior and mid-level developers
• Create and maintain technical documentation

Technical Requirements

• 5+ years of professional backend software development experience
• Hands-on experience building enterprise applications with .NET / C# (ASP.NET Core, .NET 6/7/8)
• Production experience with microservice architecture, including inter-service communication (gRPC, REST, message brokers)
• Strong understanding of SOLID principles and Clean Architecture
• Advanced query optimization and schema design experience with both SQL and NoSQL databases
• Experience with event-driven architecture using RabbitMQ, Kafka, or Azure Service Bus
• Experience working in containerized environments with Docker and Kubernetes
• Proficiency in Git-based version control and code review workflows
• Experience working in Agile teams following Scrum or Kanban

Nice to Have

• Project experience with at least one AI framework such as LangGraph, CrewAI, AutoGen, or Semantic Kernel
• Experience designing and deploying AI-powered workflows or autonomous agents
• Hands-on experience designing and implementing Retrieval-Augmented Generation (RAG) pipelines