PROFESSIONAL SUMMARY:

• Over 6 years professional experience in SQL development, ETL process implementation, reports and dashboards design.
• Abundant industry experience including healthcare, health insurance, insurance, retailers and banking.
• Expertise in developing SQL Server objects such as stored procedures, user - defined functions, views, table variables, and temporary tables based on different business requirements.
• Proficient T-SQL Skills in using CTEs, Dynamic SQL, functions and transactions.
• Excellence in performance tuning in SQL Server, SSIS and SSRS to optimize performance, including the maintenance of store procedures, optimization of queries and creation of additional indexes, etc.
• Experience in adding new and modifying data structure including adding constraints.
• Strong abilities of setting error handling, debugging, and writing transactions with T-SQL.
• Proficiency in performing ETL process including initial loads and incremental loads by using either control flow or data flow methods in SSIS.
• Rich experience with data validation, data cleaning, and data profiling in prestaging phase, data aggregation and transformation in staging phase.
• Expertise in setting logging, checkpoint, error handling and troubleshooting for ETL.
• Experience in writing C# to realize complex functionalities such as XML destinations and HTML email in SSIS.
• Excellence in designing complex reports and dashboards by using different tools, such as SSRS (SQL Server Reporting Services), Power BI and Tableau.
• Proficiency with scheduling tasks, emails, alerts and managing subscriptions.
• Expertise in business requirement gathering, exceptional interpersonal and communication skills to effectively communicate with internal and external customers.
• Essential practice of SDLC methodologies such as Agile and Scrum.
• Comprehensive abilities including cloud service (AWS and Azure), web service development, and data mining.

TECHNICAL SKILLS:

Databases: SQL Server, MySQL, Oracle Database 11g R2, MS Access

Programming Languages: SQL (T-SQL, MySQL, Oracle PL SQL), C#, VB, Python, R

BI Tools: SSMS, Visual Studio, SSIS, SSRS, Power BI, Tableau

Data Modeling Tools: Visual Paradigm, Toad Data Modeler, Draw.io

Data Analysis Tools: R, Python, Minitab, Arena Simulation, RapidMiner

Job Scheduling & Work Automation: SQL Server Job Agent, Control-M

Collaboration Platform: SharePoint

Version Control Tools: Team Foundation Server (TFS), GIT/GitHub

Cloud Service: AWS (EC2, RDS, CloudFormation, S3), Azure (Virtual Machine, SQL Database and Data warehouse, Data Factory, PowerShell, Azure Machine Learning)

Project Management Tools: JIRA, LeanKit, Trello

Other Tools or languages: Linux, HTML, PHP, Google Analytics, WordPress, Dreamweaver

PROFESSIONAL EXPERIENCE:

Database Developer

Confidential, Long Island

Responsibilities:

• Translated business requirements to technical counterparts based on gathering, clarifying, and analyzing business users’ requirements after conducting JAD sessions.
• Created stored procedures, CTEs, and dynamic SQL based on business requirements to build and implement business logic.
• Developed views, temp tables, table variables to facilitate efficient data manipulation and data consistency.
• Used aggregate function, window function, analytic function, ranking function, data and type function, and string function to fit complex business calculation.
• Performed index analysis for tables and came up with more efficient solutions to use clustered and non-clustered indexes for significant performance boost using index tuning wizard.
• Added key constraints, not null constraints, default constraints and check constraints to keep data integrity.
• Optimized the performance of slow running SQL queries utilizing appropriate changes in the code structure, utilizing indexing and partitioning strategy as well as making use of SQL Profiler.
• Built SSIS parent-child packages and leveraged a variety of other methods to import/translate/ manipulate healthcare data.
• Analyzed and worked with multiple data sources (Database, Excel file, Flat file, etc.) to meet business rules and support analytical needs.
• Created highly complex SSIS packages using various Data transformations like conditional splitting, script components, lookup, sort and for each loop containers.
• Handled incremental load using checksum and timestamps methods.
• Applied various slowly changing dimensions (SCD), such as Type 1 and Type 2 to different dimension tables.
• Implemented checkpoints, created custom logging, enabled event handlers to monitor the package process.
• Wrote C# scripts to send emails to inform users about data cleansing, to create XML destination, etc.
• Worked with business analysts and stakeholders to understand business needs and develop highly scalable solutions.
• Deployed SSIS packages to test and production server using project deployment model.
• Developed cross validation rules to ensure data accuracy.
• Documented steps needed to migrate database objects between various environments including Development, UAT, Staging, and Production.
• Designed complex SSRS reports using multiple data providers, global variables, expressions, user-defined objects, aggregate-aware objects, line charts, bar charts, cascading parameters and renderer into Excel and PDF format.
• Deployed reports created report schedules and subscriptions for daily and monthly business purpose and notification letters.
• Developed and maintained operating procedures and support documentation for reports and the SSRS infrastructure.
• Collaborated with team members using TFS for source control and for maintaining a repository of T-SQL objects, SSIS packages, and reports.
• Wrote codes reviews and improved efficiency of the team.

ETL developer

Confidential

Responsibilities:

• Implemented T-SQL server objects using T-SQL (DML, DDL, and DQL).
• Created and modified stored procedures, aggregate function, window function, analytic function, ranking function, user-defined functions, CTEs to calculate important business indicators, such as revenue per policyholder, average cost per claim, average number of claims, loss ratio and frequency.
• Developed views, temp tables, table variables to facilitate efficient data manipulation and data consistency and created constraints, such as key constraint, default constraint and not null constraint to keep data integrity.
• Utilized dynamic SQL, parameters, control flow statements, etc. into customized queries in SQL server for the requirement of users and clients.
• Analyzed long-running queries and optimized application and system performance by examining execution plan, SQL profiler, SQL Server Agent and Database Engine Tuning Advisor, and reconstructed queries for hundreds of stored procs and existing scripts by creating and modifying indexes, setting transaction location levels, and changing query structure.
• Ensured the integrity of star and snowflake schema, DB normalization, and implemented transactional replication and log shipping.
• Created initial load and incremental load packages for development in SSIS.
• Utilized sequence and foreach loop containers, send mail task, variables and expression control.
• Built parents & child packages structure in SSIS, calling child packages by looping through the package names.
• Implemented checkpoints created custom logging and error tables and enabled event handlers in SQL server to monitor the package process.
• Configured SSIS packages using Package Configuration Wizard to allow packages to run in different environments, including testing and production environments.
• Used TFS and Source control explorer to view the version history and to perform version control, errors tracking, troubleshooting, building changing, code review, modification promotion, etc.
• Monitored database service costs and maintained database server and data factories in Azure.
• Implemented Copy activity, Custom Azure Data Factory Pipeline Activities and scheduled web jobs for daily loads.
• Developed SSRS reports using multiple data providers, global variables, expressions, user-defined objects, aggregate-aware objects, line charts and bar charts, and synchronized queries for claim processing data and other information system data.
• Designed and implemented parameterized and cascading-parameterized reports with over 15 parameters using SSRS.
• Deployed reports and created scheduled subscriptions for daily and monthly business purpose and notification letters. Managed and secured reports by SSRS and rendered into Excel and PDF.
• Performed data cleansing, exploratory analysis and feature engineer using python and data visualization packages such as Matplotlib
• Implemented code in python to retrieve and manipulate data
• Collaborated with a globally distributed team using Agile Scrum methodology to analyze and solve technical and business issues for users. Communicated with product control team, front-end engineers, and back-end developers for the end-to-end service for clients and managements.
• Developed and updated team SharePoint site, incorporated various web applications, migrated, re-certified and maintained files in document center.

SQL developer

Confidential

Responsibilities:

• Attended joint application design (JAD) meetings with BI team and Actuarial Manager to obtain business requirements. Established comprehensive mapping documents.
• Followed Kimball method to maintain data warehouse with Galaxy Schema by choosing Business Process and data mart, Choosing Granularity, Choosing Dimensions and Facts.
• Configured SSIS packages by using Package Configuration Wizard to allow packages to run in different environments, including testing and production environments.
• Developed 30+ SSIS packages to accomplish the ETL process to extract data from SQL Server and Excel files, apply data cleansing, data profiling and transformation using different tasks, containers and components.
• Performed initial load and incremental load using SSIS packages and stored procedures.
• Handled incremental load using checksum and timestamps methods.
• Paralleled tasks to improve performance of SSIS packages.
• Wrote C# scripts to send emails to inform users about data cleansing, to create XML destination, etc.
• In SSIS, implemented checkpoints, created custom logging, enabled event handlers to monitor the package process.
• Implemented error handling on packages by redirecting errors and saving error log in SQL Server tables.
• Performed unit test of codes and packages with sample data following specific rules.
• Created stored procedures, user defined functions, temp tables and CTEs to support ETL and reports.
• Created various SSRS reports, such as drill down reports, drill through reports, cascading reports, sub-reports, linked reports, using Tablix, matrix, bar chart, pie chart, etc.
• Implemented cache and snapshot for improving SSRS performance.
• Implemented various indexes, such as clustered index, non-clustered index and covering index.
• Recompiled existing stored procedures to avoid parameter sniffing.
• Responded to error massage and help desk system tickets and solved issues according to user requirements.
• Be responsible for production support and worked on Jira Scrum for job scheduling.
• Manage a JIRA queue of ad hoc data requests for custom SSIS packages and T-SQL stored procedures.

BI Developer

Confidential

Responsibilities:

• Attended meetings with the test team and the tech team lead to perform regular code review and to ensure reports on UAT servers were correctly performed.
• Participated in designing destination tables in SQL Server database and implementing ETL processes to migrate data between third-party software and data marts.
• Maintained the existing ETL packages, including SSIS packages and stored procedures according to the metrics and developed SCD.
• Utilized Dynamic SQL, parameters, control flow statements, etc. into customized queries in SQL Server for the requirement of users and clients.
• Created custom logs for error handling and used event handler to provide data security, including suspicious user behavior.
• Debugged errors, fixed malignant logics, and improved the debug process and methods for packages and stored procedures.
• Aggregated the querying logs and rejected data in the ETL process into documents for future error handling.
• Applied various constraints to maintain database integrity.
• Validated data using SSIS packages, such as checking blank fields, inconsistent fields, out of bounds values and missing data.
• Developed and optimized stored procedures to do data profiling.
• Troubleshoot slowly running queries by checking the execution plan, analyzing tracing file from SQL Profiler.
• Supported the logging framework by generating reports to identify the trends and set up the strategy to find bug trends, code changes using Team Foundation Server (TFS).

Data Engineer

Confidential

Responsibilities:

• Developed new features within the Agile team environment and contributed ideas and suggestions during the team meetings.
• Consulted with business users about requirement documents, like data descriptions, data cleansing rules, and calculation formulas for complex business rules.
• Created new SQL Server objects and modified existing ones, such as stored procedures, views, functions, triggers, and other technologies to solve complex business requirements or to improve their efficiencies.
• Operated performance tuning by creating additional indexes and partitions to the database and data warehouse.
• Established table constraints, such as data types, different types of keys, null values, default values, and check to keep data integrity.
• Wrote complex queries using CTEs, subqueries, variables, and other necessary objects from the SQL Server.
• Performed code reviews to analyze inefficient or incorrect queries and provided suggestions for optimizations or debugging purposes.
• Scheduled SQL Server job agents to perform recursive tasks, such as DML statements, backups, incremental loads, and etc.
• Created or updated existing ETL packages for both initial and incremental loads from different sources, such as Excel, flat file, XML, and OLEDB, into the ideal destinations using SSIS.
• Implemented stored procedures in many purposes, such as to perform DML statements in SQL Server, to establish datasets/ data source in ETL and reporting packages.
• Performed data cleansing, data transformation, and data integration from different source types in different task scopes, such as control flows and data flow transformations.
• Developed reports and dashboards packages with subscriptions using SSRS with features such as cascading parameters, drill-down reports, drill-through reports, and pivot tables.
• Performed troubleshooting for SQL Server objects, ETL and reporting packages, and provided solutions or suggestions to eliminate bugs or to solve issues by analyzing the project and business requirements.
• Demonstrated exceptional interpersonal and communication skills, which improved team collaboration.

SQL Server database developer

Confidential

Responsibilities:

• Reviewed, profiled and validated the source metadata by querying their native database or applications.
• Established source-to-target mapping documents based on above analysis and BRD.
• Wrote stored procedures, function, sub-query, and loops in SQL server.
• Developed SSIS packages to extract data from Excel files, DB2, SQL Server using derived columns, aggregate, lookup, conditional split transformation, execute SQL task, data flow task, foreach loop container, etc.
• Created custom logging, linked precedence constraint with send mail task and execute SQL task, enabled event handlers for error handling.
• Applied data validation to check loading accuracy with specific rules, such as comparing number of loaded rows between source and destination, calculating sum of key columns, etc.
• Optimized packages by adjusting pipeline buffer size and applying parallel execution.
• Created project and package parameters for deployment to Test and Production server.
• Deployed SSIS packages to Dev server using project deployment model.
• Collaborated and communicated Production SSIS packages schedules with DBA. Scheduled jobs to run packages automatically and send job alerts with SQL Agent Job.
• Implemented error handling by applying TRY...CATCH, RAISERROR, etc.
• Modified existing databases by adding/removing columns, constraints according to requirements.
• Migrated SSIS packages from .