Senior Software Engineer

Job Description

Position summary

The Senior Software Engineer builds, maintains, and improves the backend services, APIs, and third-party integrations that power SureCost’s pharmacy purchasing and inventory platform, which over 1,600 pharmacies use every day. The role writes production software with fully agentic AI development workflows. AI agents (Claude Code or equivalent) are the main environment for writing, testing, and running code. The work is backend focused and centered on .NET, within a full-stack ownership model. The engineer owns features end to end: the API contract, the service logic, the data layer, any external integrations, the supporting UI where needed, deployment, and production support. They work in a cross-functional pod with other senior engineers and QA.

Essential duties and responsibilities

• Design, develop, and maintain backend services and RESTful APIs in C# / .NET (ASP.NET Core) on the company’s current and next-generation platforms.
• Build and maintain integrations with third-party systems, such as accounting platforms, ERP, EDI, and vendor APIs. This covers authentication (OAuth 2.0), data mapping and sync, webhooks, rate limiting, retries, idempotency, and error reconciliation.
• Design data models and write efficient, well-tested data access against relational databases (SQL Server and/or PostgreSQL), including schema migrations and query performance tuning.
• Direct agentic AI development workflows to write, test, refactor, and document code. Review agent output and confirm it passes the company’s blocking quality gates before release.
• Own delivered work end-to-end: design, implementation, automated tests, deployment, monitoring, and fixing production issues that arise from that work.
• Build and maintain automated test coverage (unit, integration, and contract tests), including AI-authored test suites, as a condition of feature completion.
• Work with the pod on API contracts. Build or modify React / TypeScript front-end code when needed to finish a feature without handoffs at team boundaries.
• Take part in sprint planning, estimation, code review, and the pod’s operational cadence. Report status and blockers clearly and early.
• Contribute to shared libraries, integration patterns, and platform foundations.

Required qualifications

• 8+ years of professional software engineering experience, with substantial production backend work in C# / .NET.
• Hands-on experience building and supporting production integrations with third-party platforms. 
• Demonstrated experience shipping production code through fully agentic AI development tools (Claude Code, Codex CLI, Cursor agent mode, or equivalent). This means using agents to write, test, and operate substantial production code, not only code completion.
• Strong proficiency in ASP.NET Core, RESTful API design, asynchronous programming, and dependency injection, plus an ORM such as Entity Framework Core and/or Dapper.
• Solid relational database skills (SQL Server and/or PostgreSQL): schema design, query optimization, and migrations.
• Working proficiency in React and TypeScript, enough to build and modify front-end features as part of full-stack delivery.
• Strong problem-solving skills: able to read unfamiliar codebases quickly, debug across layers (API, data, external systems, UI), and make sound technical decisions under time pressure.
• Working fluency in at least one major cloud platform (AWS preferred; GCP or Azure acceptable), including messaging and queuing (e.g., SQS/SNS), and the ability to learn new stacks quickly.
• Demonstrated end-to-end ownership of production software, including post-release support.

Preferred qualifications

• Experience with additional accounting, ERP, or financial integrations (e.g., Xero, NetSuite, Sage) or EDI (X12 850/855/810).
• Event-driven and asynchronous architectures: background workers, message queues, and reliable sync / reconciliation patterns.
• Containerized deployment (Docker, ECS, or Kubernetes) and infrastructure as code (Terraform).
• Observability tooling (e.g., Datadog) for tracing, logging, and alerting on integration health.
• React PWA, React Native / React Native Web, or design-system experience.
• Data-dense B2B application experience (purchasing, invoicing, ERP-style workflows).

Success measures (first 6 months)

• Independently delivers the pod’s committed backend and integration work through the release gate, sprint over sprint.
• Uses the team’s agentic development pipelines fluently, and agent-authored test coverage ships with every feature.
• Owns at least one production service or integration surface with no unresolved escaped defects attributable to delivered work.

Working relationships

Reports to the Director of Engineering (career line) and takes technical direction from the pod lead. Works daily with pod engineers, QA, the product owner, and contractor teammates.