Senior Backend Developer, Card Payment Systems
RoofStacks
full-time
Posted on:
Location Type: Hybrid
Location: Istanbul • Turkey
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Job Level
About the role
- You will take part in the full development lifecycle of our card platform, working on mission-critical services used in:
- - Card application flows for Debit, Credit, Prepaid, Digital & Commercial cards
- - Integrations with KKB/LKS, Decision Support, Analytics Solutions and onboarding systems
- - Development of card lifecycle and transaction management services (issuance, renewal, limits, fraud, posting, fee, campaign, extre, DWH etc.)
- - Secure integrations with payment schemes (Visa, Mastercard, BKM, CUP, Discover) and EMV scripting/PIN management
- - POS ecosystem integrations (TechPOS, Ingenico SDK, CAT transaction flows, parameter distributions)
- - Real-time and batch transaction processing with high availability (99.9% uptime) requirements
- - Working with ISO 8583 messaging, socket programming, TCP/IP protocols
- - Supporting authentication flows via OAuth2, OpenID Connect, JWT/JWS, and 3DS SDK/ACS
Requirements
- Minimum 5+ years of experience in software development
- Bachelor’s degree in Computer Engineering, Software Engineering, or related field
- Strong experience in C#, .NET Core / .NET Framework
- Solid command of SQL / PL-SQL (Oracle preferred)
- Experience in multi-threaded applications and performance optimization
- Prior banking or fintech experience is highly preferred
- Hands-on with RESTful API, Webhook integrations
- Strong debugging, testing, and system integration skills
- Good command of English is a plus
Applicant Tracking System Keywords
Tip: use these terms in your resume and cover letter to boost ATS matches.
Hard Skills & Tools
C#.NET Core.NET FrameworkSQLPL-SQLRESTful APImulti-threaded applicationsperformance optimizationsocket programmingISO 8583
Soft Skills
debuggingtestingsystem integration