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Skills

  • Crystal Reports
  • Oracle
  • PL/SQL
  • SQL
  • MySQL
  • PostgreSQL
  • Query Optimization
  • Stored Procedures
  • Transact-SQL
  • Data Migration
  • Database Development
  • Oracle Database
  • Process Design
  • Software Development
  • App Development

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Services

  • Oracle SQL Query Optimization and PL/SQL

    $18/hr Starting at $50 Ongoing

    Dedicated Resource

    I am an Oracle PL/SQL Developer with 7+ years of experience developing and supporting enterprise database solutions. My expertise includes Oracle Database, PL/SQL, SQL query optimization, performance...

    App DevelopmentBatch ProcessingCommunication SkillsCrystal ReportsData Analysis

  • Oracle Database Troubleshooting

    $18/hr Starting at $50 Ongoing

    Dedicated Resource

    I provide Oracle Database troubleshooting, PL/SQL debugging, and issue resolution services for organizations that need fast and reliable support. With more than 7 years of experience working with Oracle...

    Computer EngineerCrystal ReportsDatabase DevelopmentMySQLOracle

  • Data Migration and ETL Development

    $18/hr Starting at $50 Ongoing

    Dedicated Resource

    I provide ETL development, data migration, and data transformation services for organizations that need reliable and accurate data movement between systems. With more than 7 years of experience working...

    Crystal ReportsData MigrationData ProcessingDatabase DevelopmentMySQL

About

Oracle PL/SQL Developer | SQL Performance Tuning | ETL & Data Migration | 7+ Years of Enterprise Experience

Hello, I'm Miguel Ballesteros, an Oracle PL/SQL Developer with more than 7 years of experience building, optimizing, and supporting enterprise database solutions.

Throughout my career, I have worked on large-scale systems in the utilities and telecommunications sectors, participating in projects related to billing, customer service, operations, CRM, OSS, BSS, data integration, and business process automation.

My technical expertise includes:

• Oracle Database
• SQL & PL/SQL Development
• Query Optimization
• SQL Performance Tuning
• Execution Plan Analysis
• ETL Processes
• Data Migration
• Stored Procedures
• Packages, Functions, and Triggers
• Batch Processing
• Oracle Reports
• Crystal Reports
• Data Validation and Data Fixes
• Production Support

I have extensive experience working with complex business rules, large databases, and mission-critical applications where performance, reliability, and data quality are essential.

My goal is to provide efficient, maintainable, and scalable solutions while maintaining clear communication and delivering projects on time.

Whether you need help optimizing slow SQL queries, developing PL/SQL solutions, troubleshooting Oracle issues, migrating data, or supporting existing Oracle systems, I am ready to help.

I look forward to working with clients who value quality, professionalism, and long-term collaboration.

Work Terms

Hours of Operation:
Monday to Sunday: 5:00 PM - 11:59 PM (GMT-5)
Weekends: Flexible availability depending on project requirements.

Communication:
I prefer communication through Guru messages, email, or scheduled video meetings when required.

Project Approach:
• Clear understanding of requirements before starting work.
• Regular progress updates.
• Focus on quality, performance, and maintainable solutions.
• Timely delivery of agreed milestones.

Payment Terms:
• Fixed-price and hourly projects are accepted.
• For larger projects, milestone-based payments are preferred.
• Small support tasks and troubleshooting assignments are welcome.

I am committed to maintaining professional communication and delivering reliable solutions that meet business requirements.

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