Silvestre Cassa Iombo started working in the Oil Industry in 2001, after completing his training in Petroleum Engineering on December 21, 2001. In 2002, he joined SONANGOL as a trainee production engineer in the SONANGOL Production Department. As a trainee production engineer he developed a production control spreadsheet for the Girassol field. During his time at Total, he learned how to monitor well performance, equipment installation procedures, and project schedule control. After completion of internship, internship in Block 17, wrote an article about Block 17 Operations and challenges of Project Dália. In July 2003, he benefited from a petroleum process course and joined the TOTAL studies department to carry out gas field studies in Qatar using PROII and OLGA2000 software. Upon completion of the studies he wrote a technical document entitled "High Pressure Studies". He also carried out studies on the Dalia project using SHG software to perform calculations for lift gas injection. In 2004, he worked on the Rosa project as a Project Engineer whose scope was to coordinate the work between the Engineering and Operations project team. During the Service mission in Paris, he started to develop Subsea and Surface Software. Upon completion of service mission, wrote the technical report to describe the challenges of the Dalia project. In 2006, he was promoted to Project Coordinator Clov and Block 32 in the Installation Department. In 2007, he benefited from a petroleum technology training at GE oil & gas. After completing the training, he wrote a document entitled Evolution of FPSO in the World and made a presentation at SONANGOL. In 2008-2009, he was appointed as coordinator of all SONANGOL P & P projects in the Facilities Department. In 2009-2010, he joined the Kizomba Satellite Project Team as a project engineer. It created a tool to control the project completion system, it was the first time it was used for the Kizomba satellite project. He completed the oil company integrated system control software. In 2011-2014, started coordinating the team from Block 18 for the Facilities Department. In 2015-2017, she coordinated the Block 16 team at the level of the SONANGOL Production Department and Joint Development of Blocks 16 & 31. During this period, she wrote an article titled by Platinum Project Development Concept.