Sr. Software Developer – Application Migration & Modernization ( 102-08SENG-01)

This role modernizes legacy .NET applications and their data tiers onto supportable platforms. Most engagements start with a working-but-aging system — a .NET Framework 4.8 application backed by Oracle — and end with something maintainable, scalable, and testable on PostgreSQL RDS with Windows application servers on EC2. This is hands-on engineering with real constraints: production systems that can't go down, undocumented application logic, business logic buried in stored procedures nobody has read in a decade, and a migration that needs to be seamless and invisible to end users. Critically, this is not a database-only migration: the application layer itself must be modified to support PostgreSQL as the backend, not just have its data moved underneath it.

What you will do

• Assess existing .NET Framework applications — dependencies, integration points, data access patterns — and produce a realistic modernization plan with sequencing and risk called out.

• Modify the application codebase itself to support PostgreSQL as the backend, beyond just migrating the underlying data.

• Untangle and port data access layers, including legacy ADO.NET and older Entity Framework code, to current patterns.

• Migrate database workloads from Oracle to PostgreSQL: schema conversion, PL/SQL to PL/pgSQL translation, data type and collation mismatches, query rewrites, and performance validation on the target.

• Write the tests that make a migration defensible: characterization tests around legacy behaviour, integration tests across the data tier, and automated comparison of old vs. new outputs.

• Work directly with client architects, DBAs, and product owners; explain trade-offs in plain language and document decisions so the next person understands them.

• Contribute to CI/CD pipelines, deployment automation, and observability for the systems you migrate.

• Mentor mid-level developers and review code with an eye on maintainability, not just correctness.

Required

• 10+ years of professional software development experience, with significant depth in C# and .NET.

• Strong, current working knowledge of .NET Framework 4.8 and its legacy stack — ASP.NET MVC/Web API, Web Forms, WCF, IIS, and Windows Services.

• Demonstrated experience modernizing or migrating existing applications — not just greenfield development.

• Solid relational database skills: writing and tuning SQL, reading execution plans, understanding transaction and isolation behaviour.

• Hands-on Oracle experience — PL/SQL, packages, procedures, triggers, sequences — enough to read and reason about business logic living in the database.

• Experience with source control, branching strategy, and CI/CD in a team setting (Git, Azure DevOps, GitHub Actions, or similar).

• Ability to communicate clearly with non-engineers and to work well when requirements are incomplete.

Engagement details

• 100% emote

• Hourly, full-time commitment

• 2-month engagement with the possibility of extension

• Open to candidates in Latin America