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Marcello Held

@marcelloheld

Software engineer at Citibank building Open Finance currency exchange APIs; previously helped cut migration costs by over USD 1 million annually.

Brazil

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At Citibank, I design and develop currency exchange microservice APIs for Open Finance in Brazil, and support FX applications in the trade system. I work with Java, C/C++, Go, Spring Boot, Oracle DB, and OpenShift.

At Leega, I converted 30 legacy programs from C to Go and migrated a solution from Oracle Hexadata to Google BigQuery on Google Cloud. For Rede’s transaction system, I implemented Visa and Mastercard releases in a C/C++ switch that processed millions of transactions daily and supported over 2,000 TPS.

I also worked on Rede’s workflow migration from Oracle SOA applications to Java Spring Boot REST APIs on AWS ECS. The migration reduced annual costs by more than USD 1 million.

Earlier, I developed high-performance C/C++ systems for financial institutions, including a file-processing framework at Banco Itaú designed to move mainframe batch routines to Linux servers. My work has also included payment systems, ISO-8583 libraries, and a C++ cryptography library for point-of-sale devices.

Experience

Work history, roles, and key accomplishments

Current

Developer

Current

Citibank

Jul 2021 - Present (5 years 4 months)

Designed and developed robust currency exchange microservices APIs for Open Finance, ensuring seamless integration and efficient exchange processes. Provided ongoing support and maintenance to FX applications, including security patching and CVE analysis.

Java C C++Go J2EE Spring Boot Oracle DB OpenShift Jenkins Microservices Open Finance Security

Software Engineer

Leega

Oct 2016 - Jul 2021 (4 years 9 months)

Converted 30 legacy programs from C to Go and migrated solutions from Oracle to Google BigQuery on Google Cloud. Implemented Visa, Mastercard and other flagship releases in the REDE Switch transaction system, supporting over 2000 TPS.

C C++Go BigQuery Google Cloud Platform AWS Java Spring Boot Oracle SOA BPEL BPMN Terraform Sybase Splunk Gitlab

Developer

Stefanini IT

Apr 2014 - Oct 2016 (2 years 6 months)

Implemented TCP/IP Socket Connectors and ISO-8583 reader/writer libraries for the Service Authorization System. Developed a Cryptography Library for WIFI Point of Sales using DUKPT and C++ with internal load balance.

C++TCP IP ISO 8583 DUKPT HSMs Java C#Cryptography

Developer

Resource Tecnologia

Nov 2007 - Apr 2014 (6 years 5 months)

Researched, designed, and developed high-performance C/C++ programs for Itau Bank running on Linux clusters. Designed and developed the Redecard Workflow System migration from TIBCO to Oracle SOA Suite, and developed a Mastercard mobile payment app beta and the Redecard Komerci website product.

C C++Linux Oracle SOA BPM BPEL TIBCO Mastercard Cardinal Integration

Developer

T-Systems do Brasil

Jun 2006 - Nov 2007 (1 year 5 months)

Developed and designed the Redecard POS Logistics system using C++ on Unix AIX 5.3 with Oracle 10G and Sybase 12-5 databases. The system managed maintenance and distribution of POS terminals based on calculated distances and workday evaluations.

C++Unix Aix Oracle Sybase Pro*C OpenClient

Developer

Gedas do Brasil

Mar 2005 - Jun 2006 (1 year 3 months)

Maintained, designed, and developed software projects for Redecard systems, including Credit Card Point of Sales Management, WorkFlow Management, and Internet Web Site. Created new Workflow processes using ASP/Javascript/COM+ and StaffWare Workflow, integrating with C/C++ and Java programs.

ASP JavaScript COM+C C++Java Sybase Staffware Aix Mainframe

Education

Degrees, certifications, and relevant coursework

ESAN - Escola Superior de Administração de Negócios

Bachelor of Business Administration, Business Administration

1999 - 2002

Bachelor of Business Administration from ESAN - Escola Superior de Administração de Negócios from 1999 to 2002.

UNIP - Universidade Paulista

Associate, System Analysis

1996 - 1998

System Analysis Associate degree from UNIP - Universidade Paulista from 1996 to 1998.

Universidade de Brasilia

Graduate Student, Go Language Specialist

2024 -

Graduate Student Go Language Specialist program at Universidade de Brasilia from May 2024 to November 2024. Monograph on Artificial Intelligence in Decision support systems.