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Java Engineer – Application / Database Modernization (Freelancer)

1 month ago
India
Freelance
Mid Level
Backend Engineer
Software Development
AWS CI/CD DB2 Hibernate Java Oracle PostgreSQL Spring SQL SQL Server
Apply Now
Mactores

Mactores

Mactores provides data analytics solutions and services that empower businesses to enhance their operational efficiency and value through automation and advanced technologies such as AI, Big Data, and cloud computing.

IT Services
51-250
Founded 2003
View All Jobs 3

Description

  • Analyze and remediate large enterprise Java codebases to replace legacy or database-specific SQL constructs with standards-compliant SQL.
  • Convert embedded SQL within Java services and MyBatis XML mappers, including rewriting vendor-specific functions, sequences, pagination logic, dynamic SQL, and error-handling patterns.
  • Collaborate with schema and database migration engineers to align application-layer SQL with the modernized target schema.
  • Refactor Java transaction logic, error-handling, database drivers, and ORM/DAO layers to support the behavior of modern databases.
  • Participate in unit, integration, and performance testing to verify functional parity and meet post-modernization performance SLAs.
  • Support application cutover activities for production environments, including validation, monitoring setup, rollback planning, and stabilization.
  • Produce engineering documentation such as SQL remediation guides, code-migration runbooks, troubleshooting guides, and knowledge-transfer materials for customer teams.
  • Work across distributed teams (US & India) and with customer SMEs to ensure business logic alignment and successful modernization outcomes.

Requirements

  • Bachelor’s degree in Computer Science, Engineering, or a related field.
  • 3+ years of professional Java development experience using frameworks and data access layers (Spring, JDBC, MyBatis/Hibernate or equivalent).
  • Experience with application modernization, database migrations, or large-scale refactoring initiatives.
  • Strong SQL expertise with the ability to analyze, interpret, optimize, and rewrite complex SQL embedded in applications.
  • Deep understanding of JDBC, ORMs, Java transaction patterns, and database-driven application flows.
  • Experience working on enterprise-grade, high-performance applications with complex data interactions.
  • Strong communication skills and ability to work with global distributed teams across US time zones.
  • Preferred: experience with PostgreSQL or Aurora PostgreSQL and modernization from legacy databases such as Oracle, SQL Server, or DB2.
  • Preferred: exposure to automated code-refactoring tools or GenAI-assisted remediation workflows.
  • Preferred: familiarity with CI/CD environments, performance testing tools, observability stacks, and consulting/professional services delivery on fixed-timeline projects.

Benefits

  • Freelance remote opportunity with collaboration across distributed US & India teams.
  • Culture guided by Mactores’ 10 Core Leadership Principles emphasizing decision-making, collaboration, and continuous improvement.
  • Opportunity to work on enterprise digital transformation and database modernization projects with knowledge-transfer to customer teams.
  • Structured recruitment process with pre-employment assessments, managerial interviews, and HR discussion.
  • Equal opportunity employer with a non-discrimination policy covering all aspects of employment.

Interested in this position?

Apply directly on the company website

Apply Now

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