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# Fintech Developer - Trading Fees & Tax Systems (C#/.NET, Kafka)

- **Company:** Liberty Personnel Services, Inc.
- **Location:** Philadelphia, PA, United States (Remote available)
- **Experience:** Expert
- **Contract:** Permanent contract
- **Skills:** Java (Programming Language), .NET Framework, C Sharp (Programming Language), Relational Databases, Software Engineering, Data Streaming, Apache Kafka
- **Published:** October 15, 2026
- **Apply:** http://www.libertyjobs.com/findjobs-details.php?j_id=90097

## About the Role

5-12+ years of professional software development in C#/.NET (strong Java engineers considered)

 - Hands-on Kafka or similar event-streaming experience

 - Strong SQL / relational database skills

 - Strong plus: fee, billing, reconciliation or tax-lot experience

 - Bachelor's in CS/Engineering/Math or equivalent

Work model: On-site 5 days/week (Philadelphia Main Line suburb), with an annual WFH day bank.

Type: Full-time, direct hire. Salary: open, plus bonus.

## Description

Our client, a leading proprietary trading firm, needs a C# engineer to own the systems that price every fee tied to a trade, in near real time. You'll sit directly with Operations, Accounting and Tax, and the work shows up on the P&L every day.

What you'll do

 - Build near-real-time P&L estimates for brokerage, exchange and market-data fees

 - Develop reconciliation and bill-payment processing workflows

 - Maintain and extend the tax-lot tracking and reporting system

 - Stream and process trade events using Kafka

 - Partner daily with Operations, Accounting and Tax users