E-Commerce Backend Developer Job Izmit area,İzmit Turkey (Türkiye),Software Development

Location: İzmit

Employee Type: Full Time – Office
Job Type: E-Commerce Backend Developer
Industry: E-Commerce / B2B Marketplace

E-Commerce Backend Developer | ToptanTR

As part of our consulting engagement with ToptanTR, we are looking for an E-Commerce Backend Developer to join the ToptanTR team.

ToptanTR is a multi-vendor B2B wholesale marketplace where sellers list and manage their products, buyers make wholesale purchases, and order, payment, shipping, commission and invoicing processes are all handled under one roof.

We are looking for a teammate who will build new features on a .NET-based platform that handles real order and payment traffic, and who will continuously improve system performance and reliability by measuring them.

What You’ll Do

Develop features across catalog, search, cart, campaign, coupon, order, payment, shipping, commission and invoicing processes
Build and maintain 3D Secure virtual POS, shipping carrier, ERP and e-invoice integrations
Analyze and optimize SQL Server queries and stored procedures using execution plans
Monitor database performance and carry out the necessary query and index optimizations
Design and develop Redis caching and cache invalidation strategies
Improve the quality, performance and ranking of search results with Meilisearch
Make Hangfire background jobs reliable and observable
Back your work with xUnit unit tests
Take an active part in code reviews
Analyze production issues using Sentry and Grafana data to identify their root causes

What We’re Looking For

Experience developing production applications with C# and ASP.NET Core
Strong knowledge of SQL Server, T-SQL, indexing and execution plan analysis
Practical experience with caching, concurrency and data consistency
Experience with REST API design and third-party service integrations
A habit of writing unit tests
Experience working in a team with Git-based development and code reviews
A development approach focused on performance, scalability and reliability

Nice to Have

Experience with nop Commerce or similar plugin-based e-commerce platforms
Knowledge of marketplace business rules such as commissions, seller payouts and seller management
Experience with Docker, Kubernetes (AWS EKS) and CI/CD
Experience with Meilisearch or Elasticsearch
Experience with linq2db, Dapper or Fluent Migrator
Experience with load testing and performance profiling