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Java+C# Development Lead
Job Location:
Job Location:
Columbus, OH - USA
Monthly Salary:
Not provided by the employer
Monthly Salary:
Posted:
18 September 2026 (18 hours ago)
Posted:
Application Deadline:
16 December 2026
Application Deadline:
Vacancies:
1 Vacancy
Vacancies:
Job Summary
About the role
IL4 is natively built on both Java and C#. This role is the true bidirectional profile: a developer who reads and
writes both languages fluently and can move between them daily. The work includes converting Java services to
C# using AI-assisted conversion as a first pass plus hands-on rework and working across the existing Java and C#code as the architecture consolidates. This is the hardest of the Crown profiles to fill so screen tightly.
What you will do
Work across both Java and C# code in the IL4 codebase moving between them as the work demands.
Convert Java services to C# / .NET using AI-generated first drafts as a starting point and finishing them by
hand to the client& C# patterns.
Review AI-converted output for correctness missed edge cases hallucinated APIs and behavior drift
between the Java original and the C# result.
Map Java constructs to equivalents (Spring to Core JPA/Hibernate or DAO/SQL to EF or
Dapper Maven to NuGet).
Preserve service contracts: REST endpoints payloads error handling and config behave the same after
conversion.
Write or port tests to prove functional parity before and after migration.
Must have qualifications:
Deep current Java: 8 years production Java current within the last 1-2 years. Spring Boot strongly
preferred. Can read unfamiliar Java and explain what it does and why.
Strong C# / .NET: 5 years hands-on C# Core / .NET 6 Core Web APIs dependency
injection async/await.
Real migration scars: Has personally converted or re-platformed code between different languages (not
just a framework version upgrade inside one language) and can describe what broke and how they proved
parity.
Both languages current: Shipped production code in each within roughly the last two years not one
current and one from a decade ago.
Parity discipline: Proves equivalence with automated tests not visual inspection.
Nice to have
Hands-on use of AI coding tools for conversion or large refactors with an honest view of where they fail.
Interest in building the conversion harness: prompt templates pattern libraries parity test frameworks.
Docker/Kubernetes AWS or Azure API gateways (Kong) MySQL and SQL Server.
IL4 is natively built on both Java and C#. This role is the true bidirectional profile: a developer who reads and
writes both languages fluently and can move between them daily. The work includes converting Java services to
C# using AI-assisted conversion as a first pass plus hands-on rework and working across the existing Java and C#code as the architecture consolidates. This is the hardest of the Crown profiles to fill so screen tightly.
What you will do
Work across both Java and C# code in the IL4 codebase moving between them as the work demands.
Convert Java services to C# / .NET using AI-generated first drafts as a starting point and finishing them by
hand to the client& C# patterns.
Review AI-converted output for correctness missed edge cases hallucinated APIs and behavior drift
between the Java original and the C# result.
Map Java constructs to equivalents (Spring to Core JPA/Hibernate or DAO/SQL to EF or
Dapper Maven to NuGet).
Preserve service contracts: REST endpoints payloads error handling and config behave the same after
conversion.
Write or port tests to prove functional parity before and after migration.
Must have qualifications:
Deep current Java: 8 years production Java current within the last 1-2 years. Spring Boot strongly
preferred. Can read unfamiliar Java and explain what it does and why.
Strong C# / .NET: 5 years hands-on C# Core / .NET 6 Core Web APIs dependency
injection async/await.
Real migration scars: Has personally converted or re-platformed code between different languages (not
just a framework version upgrade inside one language) and can describe what broke and how they proved
parity.
Both languages current: Shipped production code in each within roughly the last two years not one
current and one from a decade ago.
Parity discipline: Proves equivalence with automated tests not visual inspection.
Nice to have
Hands-on use of AI coding tools for conversion or large refactors with an honest view of where they fail.
Interest in building the conversion harness: prompt templates pattern libraries parity test frameworks.
Docker/Kubernetes AWS or Azure API gateways (Kong) MySQL and SQL Server.
Required Experience:
Senior IC
