Senior Software Engineer - API & Integration Lead

We are seeking a Senior Software Engineer - API & Integration Lead to serve as the engineering lead for Ensemble 2.0, a business-critical integration platform that connects external partners with Greentech and CED systems. Working closely with the Principal Software Engineer / Architect and Product Owner, this role will translate architecture into production-ready C#/.NET services, establish reusable API, SQL Server, and integration patterns, and guide the phased migration of legacy workflows. The ideal candidate combines deep hands-on engineering skill with the judgment and communication needed to mentor teammates and build services that are reliable, observable, auditable, and supportable., * Partner with the Principal Software Engineer / Architect to implement system boundaries, migration strategy, technical standards, and production-readiness requirements.

• Establish and demonstrate reusable patterns for C#, ASP.NET Core, SQL Server, background processing, and partner integrations.
• Design and build secure, versioned APIs and SQL-backed workflows that exchange business-critical data with internal and external systems.
• Define and implement payload validation, authentication, authorization, error handling, retry and replay behavior, duplicate prevention, audit trails, and correlation across services.
• Analyze, document, and migrate legacy business logic into centralized, testable, and maintainable services while ensuring behavioral parity with existing production workflows.
• Lead technical implementation for complex workflows involving projects, milestones, invoices, credits, remittance activity, and related operational data.
• Review code and technical designs; mentor engineers through documentation, implementation examples, pairing, and actionable feedback.
• Collaborate with Product, QA, and Support to refine acceptance criteria, identify edge cases, improve testability, and determine release readiness.
• Troubleshoot production and pre-production issues using logs, traces, payloads, database records, and monitoring data; drive durable corrective action.
• Create and maintain technical documentation for integration contracts, implementation patterns, operational behavior, and support procedures.

• Bachelor’s degree in Computer Science, Information Systems, Engineering, or an equivalent combination of education and professional experience.
• 7+ years of professional software development experience, including substantial work on enterprise APIs, integration platforms, or distributed business systems.
• Strong hands-on experience with C#, ASP.NET Core, SQL Server, REST APIs, JSON contracts, and OpenAPI/Swagger. Experience implementing data-access repositories using parameterized SQL and stored procedures is highly preferred.
• Strong SQL Server experience, including relational data modeling, stored procedures, transactions, indexing, query tuning, and data-integrity controls.
• Experience designing or operating production integrations that use message processing, asynchronous workflows, or background services.
• Practical understanding of authentication, authorization, API versioning, idempotency, retries, deduplication, correlation IDs, structured logging, and observability.
• Experience supporting business-critical production systems and diagnosing issues across application logs, API payloads, and database records.
• Strong written and verbal communication skills, including the ability to explain design decisions, give constructive code-review feedback, and collaborate across Product, QA, Support, and Architecture., * Experience with Azure DevOps, CI/CD pipelines, App Services, Azure Functions, Service Bus, Key Vault, Application Insights, or comparable platform tooling.
• Experience with SQL Service Broker, SQL-backed queues, background workers, or other asynchronous processing patterns.
• Experience analyzing, documenting, and migrating legacy business applications. Experience modernizing Node.js, JavaScript, TypeScript, or similar systems into .NET-based architectures is highly desirable.
• Experience with file-based integrations such as CSV, remittance, EDI, or scheduled data ingestion.
• Experience working with business-critical integrations, financial transactions, operational workflows, or large-scale data migrations. Prior experience in distribution, finance, renewable energy, ERP, or logistics environments is helpful but not required.
• Experience with API contract testing, automated regression testing, performance testing, and production-readiness gates.
• Previous technical-lead or mentoring experience, particularly on a small product engineering team.

The compensation range for this position is $150000 to $170000 annually., * 401(k) (18 or older)

• Paid Sick Leave (Full-Time)
• Paid Sick Leave (Part-Time) - per your State’s requirements
• Insurance (Full-Time) - Medical, Dental, Vision Care
• Insurance (Part-Time) - Medical only (30+ hours/week)
• Disability Insurance
• Life Insurance
• Paid Holidays
• Paid Vacation
• Paid Pregnancy & New Parent Leave
• Health Savings Account (HSA) and matching
• Dependent Care Flexible Spending Account (FSA)
• Teledoc

Greentech Renewables is a leading national distributor of solar, energy storage, and renewable energy products. We partner with contractors, developers, and businesses across the United States to deliver the equipment, expertise, and support needed to power the clean energy transition. Our mission is to help customers succeed while creating opportunities for our employees to grow, innovate, and make a meaningful impact in the rapidly expanding renewable energy industry.