# Marcello Held Marcello Held is a remote worker on Himalayas, Developer at Citibank, based in Brazil. Source: https://himalayas.app/@marcelloheld ```text Software engineer at Citibank building Open Finance currency exchange APIs; previously helped cut migration costs by over USD 1 million annually. ``` | Detail | Value | | --- | --- | | Availability | Looking for a job | | Location | Brazil | | Authorized to work in | Brazil | | Salary expectations | 25k+ BRL | | Job categories | Software Engineer, Principal Software Engineer, Developer | | Skills | Java, C, C++, Distributed Systems, Linux Development, High Performance Computing, Payment Systems, Open Finance, Microservices, Cloud Native Architecture, AWS, Go, Spring Boot, Google Cloud Platform, BigQuery | | LinkedIn | https://linkedin.com/in/marcello-held | ## About ```text 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 ### Developer (current) Citibank. Jul 2021 - Present ```text 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. ``` Skills: Java, C, C++, Go, J2EE, Spring-Boot, Oracle-DB, OpenShift, Jenkins, Microservices, Open-Finance, Security ### Software Engineer Leega. Oct 2016 - Jul 2021 ```text 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. ``` Skills: C, C++, Go, BigQuery, Google-Cloud-Platform, AWS, Java, Spring-Boot, Oracle-SOA, BPEL, BPMN, Terraform, Sybase, Splunk, Gitlab ### Developer [Stefanini IT](https://himalayas.app/companies/stefanini). Apr 2014 - Oct 2016 ```text 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. ``` Skills: C++, TCP-IP, ISO-8583, DUKPT, HSMs, Java, C#, Cryptography ### Developer Resource Tecnologia. Nov 2007 - Apr 2014 ```text 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. ``` Skills: C, C++, Linux, Oracle-SOA, BPM, BPEL, TIBCO, Mastercard, Cardinal-Integration ### Developer T-Systems do Brasil. Jun 2006 - Nov 2007 ```text 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. ``` Skills: C++, Unix, Aix, Oracle, Sybase, Pro\*C, OpenClient ### Developer Gedas do Brasil. Mar 2005 - Jun 2006 ```text 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. ``` Skills: ASP, JavaScript, COM+, C, C++, Java, Sybase, Staffware, Aix, Mainframe ## Education ### ESAN - Escola Superior de Administração de Negócios Bachelor of Business Administration, Business Administration. 1999 - 2002 ```text Bachelor of Business Administration from ESAN - Escola Superior de Administração de Negócios from 1999 to 2002. ``` ### UNIP - Universidade Paulista Associate, System Analysis. 1996 - 1998 ```text System Analysis Associate degree from UNIP - Universidade Paulista from 1996 to 1998. ``` ### Universidade de Brasilia Graduate Student, Go Language Specialist. 2024 - Present ```text Graduate Student Go Language Specialist program at Universidade de Brasilia from May 2024 to November 2024. Monograph on Artificial Intelligence in Decision support systems. ``` ### E.T.E Getulio Vargas Technician, Electronics. 1992 - 1995 ```text Electronic Technician degree from E.T.E Getulio Vargas from 1992 to 1995. ``` ## Tech stack - Splunk - Google Cloud Platform - GitLab - Jenkins - MongoDB - Cassandra - Oracle - Sybase - Spring Boot - Terraform - JavaScript - Java - C# - Go - C++ - C - XML - Kafka - Hibernate - Windows - Apache Camel - Google BigQuery - SQL - AWS - Angular - HTML - CSS To contact Marcello, message them from this profile with a Himalayas employer account: [Hire on Himalayas](https://himalayas.app/hire). ## People also viewed - [Lucas Nascimento](https://himalayas.app/@lucasnascimento): Senior Back end Engineer, Bubbles - [Danilo Lemos](https://himalayas.app/@danilolemos): Freelance Developer, Luda Tecnologia - [Thiago Augusto](https://himalayas.app/@thiagoaugusto): Senior Java Software Engineer, PagBank - [Deyve Dev](https://himalayas.app/@deyvedev): Kotlin Developer, NTT Data - [Adir Vicente](https://himalayas.app/@adirvicente): Tech Lead, Casas Bahia Group - [Luiz Augusto Puglisi](https://himalayas.app/@lapuglisi): Senior C++/C# Engineer, viaStore Toyota Automated Logistics (TAL) - [André Carvalho](https://himalayas.app/@andrcarvalho): Senior Java Software Engineer, via GFT Technologies, Mastercard - [Anderson Rodrigues](https://himalayas.app/@andersonrodrigues1): Senior Software Engineer, Nubank - [Pedro Neto](https://himalayas.app/@pedroneto1): Senior Java Backend Developer, ACT Digital - [Igor Daniel](https://himalayas.app/@igordaniel): Senior Java Engineer | Backend & Distributed Systems, mastercard