Java Engineer - Application

About the role

You will own the application layer of an Oracle-to-PostgreSQL migration for a large enterprise, working inside a production-first engagement where the goal is shipped outcomes, not stalled pilots. You will partner with product owners and architects to understand complex business flows and translate them into resilient Java services that operate reliably on cloud-native infrastructure. You will leverage Aedeon-generated artifacts and insights to eliminate repetitive discovery and validation work, focusing your effort on the refactoring and integration decisions that require human judgment. You will design and implement the changes to Java code and SQL logic needed to align the application with a modernized PostgreSQL schema while preserving functional behavior and data integrity. You will collaborate closely with platform and database specialists to ensure cutover plans are executable, rollback paths are clear, and monitoring supports smooth production launches. You will write tests and validation logic to prove parity between the legacy behavior and the new implementation, turning ambiguous legacy semantics into explicit, testable contracts. You will communicate progress and risk clearly to stakeholders, translating technical tradeoffs into decisions that keep the migration on schedule and within budget. You will contribute to the playbook for future engagements, capturing patterns and pitfalls that help Mactores ship similar modernizations at scale without repeating past mistakes.

Key facts

What you'll do

Analyze existing Java application modules to identify tightly coupled Oracle-specific patterns and high-risk areas for migration.

Refactor business logic in Java services to remove dependencies on Oracle-specific features and align with PostgreSQL capabilities.

Rewrite and optimize SQL statements generated by the application, ensuring correctness, performance, and compatibility with the new schema.

Collaborate with the platform team to integrate Aedeon-generated artifacts into development workflows and CI pipelines.

Validate functional parity between legacy Oracle-dependent behavior and the new PostgreSQL-backed implementation through automated and manual testing.

Participate in architecture reviews to define service boundaries, data access strategies, and integration contracts for the modernized system.

Support the creation of cutover and rollback plans for the application layer, including runbooks and verification steps.

Work with QA and operations partners to design monitoring, alerting, and diagnostic checks that reflect the new environment.

Translate legacy SQL and PL/SQL constructs into idiomatic PostgreSQL patterns while preserving edge-case logic.

Estimate effort for refactoring tasks, flag complexity early, and propose incremental approaches that de-risk the migration.

Document key decisions, assumptions, and interfaces so that future teams can maintain and extend the system without relying on original authors.

Partner with the Mactores delivery team to incorporate Aedeon insights into sprint planning and technical design sessions.

Requirements

You must have hands-on experience building and maintaining Java applications that interact with Oracle databases in enterprise environments.

You must understand relational database concepts deeply, including transactions, isolation levels, constraints, and execution plans.

You must be comfortable reading and rewriting complex SQL, including joins, subqueries, analytic functions, and stored procedures.

You must have experience with JDBC or an ORM such as Hibernate, and you must understand how mapping and lazy loading affect database behavior.

You must know PostgreSQL well enough to model schemas, write performant queries, and use tooling for migration and debugging.

You must be able to work effectively in a remote-first, agent-assisted delivery model, relying on structured artifacts and clear communication.

You must be comfortable distinguishing between problems that require human judgment and repetitive work that can be automated by an agent platform.

You must be able to estimate the effort and risk of refactoring tasks and communicate tradeoffs to non-technical stakeholders.

Nice to have

Experience with large-scale database migrations, especially Oracle to PostgreSQL, is strongly preferred.

Familiarity with Aedeon or agent-assisted development practices is a plus, as is background in continuous delivery for Java services.

Practical notes

This is a full-time, remote engagement based out of Mumbai, India. Travel is not required as part of this role. There are no visa sponsorship or relocation support details provided in this description. The engagement is ongoing, and successful candidates may be asked to participate in multiple concurrent modernization programs.