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Ivan Quitschal

@ivanquitschal

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Senior C/C++ systems engineer specializing in low-latency financial and distributed systems on Linux.

Brazil

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What I'm looking for

I’m looking for a Senior C/C++ role on Linux where I can modernize mission-critical financial systems, build low-latency distributed components, and deliver production performance and reliability in regulated, high-availability environments.

I’m a Senior Software Engineer with 25+ years designing, developing, and modernizing mission-critical systems for Financial Services, Telecommunications, Information Security, and Retail. My focus is C/C++ and Linux/Unix systems programming—especially concurrency, IPC, shared memory, and performance optimization.

For more than 13 years, I supported critical financial platforms at Citigroup, including trade distribution, account processing, reconciliation, and mainframe integration. I led a strategic migration from Solaris to Red Hat Enterprise Linux, including more than 100,000 lines of source code, and redesigned IPC components to match architectural differences between operating systems.

More recently, I led the complete redevelopment of a legacy Visual FoxPro POS platform into a modern native Linux C++ solution. I designed and built the new POS architecture with wxWidgets, integrated PostgreSQL and SQLServer, implemented OpenSSL-based secure communications, and supported NFC-e fiscal processing with SEFAZ web services, TEF payments, and XML/signature generation.

I also contribute to the FreeBSD Project since 1999, including ANSI C device driver development and kernel-level contributions. I bring a production-tested, troubleshooting-first mindset using tools like GDB and Valgrind, plus a deep respect for reliability and high availability.

Experience

Work history, roles, and key accomplishments

Current

Senior Software Engineer

Current

HRTech

Apr 2025 - Present (1 year 3 months)

Leading the redevelopment of a legacy Visual FoxPro POS platform into a modern native Linux C++ solution. Delivering POS architecture, desktop development with wxWidgets, database integrations, secure communications, NFC-e fiscal implementation, and SEFAZ/TEF integrations.

C++Linux WxWidgets PostgreSQL SQL Server ODBC OpenSSL NFC E Libxml2 XML Security SEFAZ Web Services TEF Debian Packaging NFC e Fiscal Implementation

Current

FreeBSD Project Contributor

Current

FreeBSD Project

Jan 1999 - Present (27 years 6 months)

Long-term contributor to the FreeBSD operating system, including ANSI C systems programming and kernel-level contributions. Contributed device driver development, hardware compatibility improvements, and code review.

ANSI C Systems Programming Device Driver Development Kernel Level Code Review FreeBSD

Senior Systems Developer

Citigroup North America

Jan 2011 - Oct 2024 (13 years 9 months)

Responsible for mission-critical financial systems supporting trade and account distribution between upstream trading platforms and downstream mainframe environments. Led migration from Solaris to Red Hat Enterprise Linux and handled IPC redesign, performance investigations, and production troubleshooting.

C C++Linux Red Hat Enterprise Linux IPC Shared Memory Mutexes Locks Multithreading Low Latency Systems Distributed Systems GDB Valgrind Root Cause Analysis Sybase Oracle Git Bitbucket Jira TeamCity Artifactory

Software Engineer

Fidelity National Information Services (FIS)

Jan 2009 - Jan 2011 (2 years)

Developed financial transaction processing systems using IST, SWITCH, Clearing, and MAS APIs, including RedeCard customizations. Worked on mission-critical C development.

C Transaction Processing IST API Switch API MAS RedeCard Customization API Development