Remote: Senior API & Integration Lead — C#/.NET

3e Co; Omaha (NE); Remote; USD 150,000 - 170,000; Full time

Benefits offered by this job

401(k)

Paid Sick Leave

Paid Holidays

Paid Vacation

Health Insurance

Teledoc

Job summary

Greentech Renewables is seeking a Senior Software Engineer - API & Integration Lead to drive Ensemble 2.0, a critical integration platform linking external partners with Greentech and internal systems. You will translate architecture into production-ready C#/.NET services, establish reusable API, SQL Server, and integration patterns, and guide migration of legacy workflows.

The ideal candidate has hands-on engineering expertise and can mentor teammates, delivering reliable, observable,

Qualifications

• Bachelor's degree in Computer Science, Information Systems, Engineering, or equivalent.
• 7+ years of professional software development experience, including enterprise APIs or integration platforms.
• Strong hands-on experience with C#, ASP.NET Core, SQL Server, REST APIs, JSON contracts, and OpenAPI/Swagger; experience with parameterized SQL and stored procedures preferred.
• Strong SQL Server experience including data modeling, stored procedures, transactions, indexing, and data-integrity controls.
• Experience designing/operating production integrations with message processing, asynchronous workflows, or background services.
• Understanding of authentication, authorization, API versioning, idempotency, retries, deduplication, correlation IDs, logging, and observability.
• Excellent communication and collaboration across Product, QA, Support, and Architecture.

Responsibilities

• Partner with Principal Software Engineer to set technical standards and production-readiness requirements.
• Establish reusable patterns for C#, ASP.NET Core, SQL Server, and integrations.
• Design and build secure, versioned APIs and SQL-backed workflows exchanging data with internal/external systems.
• Define payload validation, auth, error handling, retries, deduplication, audits, and correlation across services.
• Migrate legacy logic into centralized, testable services maintaining parity with production workflows.
• Lead technical implementation for complex workflows involving projects, invoices, remittance data, and related data.
• Review designs, mentor engineers, and provide actionable feedback.

Skills

C#

ASP.NET Core

SQL Server

REST APIs

JSON contracts

OpenAPI/Swagger

Parameterized SQL

Education

Bachelor's degree in CS/IS/Engineering

Tools

Azure DevOps

CI/CD pipelines

App Services

Azure Functions

Service Bus

Key Vault

Application Insights

Job description

Greentech Renewables is seeking a Senior Software Engineer - API & Integration Lead to drive Ensemble 2.0, a critical integration platform linking external partners with Greentech and internal systems. You will translate architecture into production-ready C#/.NET services, establish reusable API, SQL Server, and integration patterns, and guide migration of legacy workflows.

The ideal candidate has hands-on engineering expertise and can mentor teammates, delivering reliable, observable,