Sr. Software Developer – Application Migration & Modernization

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Sr. Software Developer – Application Migration & Modernization based in Brazil.

This is a hands-on engineering role focused on modernizing legacy .NET applications and their underlying data platforms. You will transform mature, business-critical systems into maintainable, scalable, and testable solutions. The work spans both application and database layers, including migrating .NET Framework applications from Oracle to PostgreSQL on AWS. You’ll tackle real-world modernization challenges such as undocumented logic, legacy data access patterns, stored procedures, and production constraints. Success requires careful planning, strong testing, and a focus on seamless migrations with minimal disruption to users. You’ll collaborate closely with architects, DBAs, product owners, and engineering teams while helping raise development standards across the team.

• Assess existing .NET Framework applications, identifying dependencies, integrations, data access patterns, technical risks, and modernization priorities.
• Develop realistic modernization and migration plans, including sequencing, dependencies, risks, and mitigation strategies.
• Modify application code to support PostgreSQL as the target backend, ensuring the migration goes beyond simply moving the underlying data.
• Modernize and migrate legacy data access layers, including ADO.NET and older Entity Framework implementations, toward current and maintainable patterns.
• Migrate Oracle workloads to PostgreSQL, including schema conversion, PL/SQL-to-PL/pgSQL translation, data type and collation changes, query rewrites, and performance validation.
• Analyze and preserve business logic embedded in legacy database objects such as packages, procedures, triggers, and sequences.
• Develop characterization, integration, and automated comparison tests to validate application behavior and make migrations reliable and defensible.
• Contribute to CI/CD pipelines, deployment automation, monitoring, and observability for modernized applications.
• Collaborate directly with architects, DBAs, product owners, and other stakeholders, translating technical trade-offs into clear business language.
• Document architectural and technical decisions to ensure solutions remain understandable and maintainable.
• Mentor mid-level developers and conduct code reviews with a strong focus on maintainability, quality, and long-term sustainability.

Requirements:

• 10+ years of professional software development experience, with substantial hands-on expertise in C# and .NET.
• Strong current knowledge of .NET Framework 4.8 and legacy technologies including ASP.NET MVC/Web API, Web Forms, WCF, IIS, and Windows Services.
• Proven experience modernizing or migrating existing applications, rather than focusing exclusively on greenfield development.
• Strong relational database expertise, including SQL development and tuning, execution-plan analysis, transactions, and isolation behavior.
• Hands-on experience with Oracle and PL/SQL, including packages, procedures, triggers, and sequences, with the ability to understand business logic embedded in database code.
• Practical experience migrating or adapting applications and databases to PostgreSQL, including data types, queries, schema structures, and performance considerations.
• Experience with source control, branching strategies, and CI/CD tools such as Git, Azure DevOps, GitHub Actions, or comparable platforms.
• Strong analytical and problem-solving abilities, particularly when working with undocumented systems or incomplete requirements.
• Clear communication skills and the ability to explain technical decisions and trade-offs to non-technical stakeholders.
• Collaborative mindset, ownership, and the ability to work effectively in distributed teams.
• Experience mentoring developers and reviewing code with an emphasis on maintainability and engineering quality.

Benefits:

• 100% remote working arrangement.
• Full-time, hourly engagement.
• Initial 2-month contract with the possibility of extension.
• Open to candidates based in Brazil and across Latin America.
• Opportunity to work on complex, production-critical application modernization and cloud migration projects.
• Hands-on exposure to .NET modernization, Oracle-to-PostgreSQL migration, AWS infrastructure, automation, testing, and CI/CD.
• Collaborative environment involving architects, DBAs, product owners, and experienced engineering teams.

We use an AI-powered matching process to ensure your application is reviewed quickly, objectively, and fairly against the role's core requirements. Our system identifies the top-fitting candidates, and this shortlist is then shared directly with the hiring company. The final decision and next steps (interviews, assessments) are managed by their internal team.

We appreciate your interest and wish you the best!

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