.NET Core API & Integration Developer (Fintech)

Quara Ai Tech; United States; Remote; USD 90,000 - 130,000; Full time

Job summary

Quara Ai Tech seeks a .NET Core API & Integration Developer to design, build, and maintain high-throughput APIs and middleware integrations for a fintech platform. You will connect core financial services, payment gateways, credit bureau systems, and third-party APIs with strong security and database performance.

Responsibilities include creating secure RESTful and SOAP services, integrating internal engines with providers, and optimizing SQL Server operations while enforcing OAuth2/JWT/mTLS

Qualifications

• 4 years of experience with .NET Core (C#), ASP.NET Web API, Entity Framework, and LINQ.
• Proven ability to design and consume REST and SOAP APIs, with XML/JSON parsing experience.
• Strong SQL Server skills including indexing, query tuning, and transactions.
• Experience with Bitbucket/Git, Postman, and Swagger/OpenAPI for API docs.
• Domain experience in Fintech, Banking, or Financial Institutions is a plus.

Responsibilities

• Design, build, and deploy secure RESTful APIs and SOAP services using .NET Core.
• Integrate internal finance engines with external providers like payment gateways and government portals.
• Write optimized SQL Server procedures and queries to support high-volume transactions.
• Implement API security protocols (OAuth2, JWT, mTLS, API keys).
• Collaborate using Bitbucket/Git, review pull requests, and document APIs with Swagger/OpenAPI.

Skills

.NET Core

C#

ASP.NET Web API

Entity Framework

LINQ

RESTful APIs

SOAP services

Security protocols

OAuth2 / JWT / mTLS

Tools

Bitbucket / Git

Postman

Swagger/OpenAPI

Job description

Position Summary

We are seeking a .NET Core API & Integration Developer to design, build, and maintain high-throughput APIs and middleware integrations for our fintech platform. You will be responsible for connecting core financial services, payment gateways, credit bureau systems, and third-party APIs while maintaining strict security and database performance standards.

Key Responsibilities

• API Development: Design, build, and deploy secure, high-performance RESTful APIs and SOAP services using .NET Core.
• System Integrations: Integrate internal finance engines with external third-party providers (e.g., payment gateways, credit scoring/SIMAH, government portals, identity verification).
• Database Operations: Write optimized SQL Server stored procedures, transactions, and queries to support heavy financial transaction loads reliably.
• Security & Authentication: Implement robust API security protocols (OAuth2, JWT, mTLS/Client Certificates, API Keys).
• Version Control: Manage code repositories, feature branching, and pull requests via Bitbucket.
• Performance Tuning: Troubleshoot API latency, handle payload parsing (JSON/XML), and ensure zero data loss during high-concurrency requests.

Technical Requirements

• Core Stack: 4 years of hands-on experience in .NET Core (C#), ASP.NET Web API, Entity Framework, and LINQ.
• Integrations: Proven track record of developing and consuming complex REST and SOAP APIs, handling XML/JSON parsing, and implementing mTLS security.
• Database: Strong command of MS SQL Server (indexing, query tuning, transaction management).
• Tools: Proficiency in Bitbucket / Git, Postman, and Swagger/OpenAPI documentation.
• Domain: Direct experience developing backend services or API middleware for Fintech, Banking, or Financial Institutions.