ETL/ Data Engineer (Talend)

Good experience in the Extraction, Transformation, and Loading (ETL) of data from various sources into Data Warehouses and Data Marts using Informatica Power Center (Repository Manager, Designer, Workflow Manager, Workflow Monitor, Metadata Manager), Power Connect as ETL tool on Oracle, and SQL Server Databases.  Knowledge of Data Warehouse/Data mart, ODS, OLTP, and OLAP implementations teamed with project scope, Analysis, requirements gathering, data modeling, ETL Design, development, System testing, Implementation, and production support.  Strong experience in Dimensional Modeling using Star and Snow Flake Schema, Identifying Facts and Dimensions  Used various transformations like Filter, Expression, Sequence Generator, Update Strategy, Joiner, Stored Procedure, and Union to develop robust mappings in the Informatica Designer.  Developed mapping parameters and variables to support SQL override.  Created applets to use them in different mappings.  Created sessions, configured workflows to extract data from various sources, transformed data, and loading into the data warehouse.  Used Type 1 SCD and Type 2 SCD mappings to update slowly Changing Dimension Tables.  Modified existing mappings for enhancements of new business requirements.  Involved in Performance tuning at source, target, mappings, sessions, and system levels.  Prepared migration document to move the mappings from development to testing and then to production repositories  Extensive experience in developing Stored Procedures, Functions, Views and Triggers, Complex SQL queries using PL/SQL.  Experience in resolving on-going maintenance issues and bug fixes; monitoring Informatica /Talend sessions as well as performance tuning of mappings and sessions.  Experience in all phases of Data warehouse development from requirements gathering for the data warehouse to develop the code, Unit Testing, and Documenting.  Extensive experience in writing UNIX shell scripts and automation of the ETL processes using UNIX shell scripting.  Experience in using Automation Scheduling tools like Control-M.  Hands-on experience across all stages of Software Development Life Cycle (SDLC) including business requirement analysis, data mapping, build, unit testing, systems integration, and user acceptance testing.  Build, operate, monitor, and troubleshoot Hadoop infrastructure.  Develop tools and libraries, and maintain processes for other engineers to access data and write MapReduce programs.