We are looking for a great, client-facing Senior Backend Engineer with .NET and strong AWS experience to join our team as a Project Lead

Job Description

In this role, you’ll own a production .NET backend as the project lead, working directly with the client and acting as their technical point of contact.

You’ll start by leading a stabilization of the inherited backend over roughly four weeks, covering security, deployment, test coverage, and the worst legacy hot spots. After that, you’ll ship feature batches from the API to the database, owning the API and data model for each one.

The backend runs on .NET 10 with EF Core 10, SQL Server (Azure SQL in staging, AWS RDS in production), and in-process Hangfire jobs, deployed with Docker and GitHub Actions to AWS ECR and App Runner, with Auth0 for authentication and AWS S3.

Committed to

- Owning the backend project end-to-end as the project lead.
- Leading a ~4-week stabilization of the inherited backend, covering security, deployment, test coverage, and the worst legacy hot spots.
- Shipping feature batches on the backend, owning the API and data model for each.
- Keeping the OpenAPI contract up to date as the API changes.
- Owning CI/CD, environments,



and secrets on GitHub Actions and AWS.
- Acting as the technical point of contact for the client.

Must have

- Senior-level, deep .NET / C#, EF Core, and SQL Server experience in production, with strong SQL knowledge.
- Experience owning a project, comfortable leading a legacy codebase solo and working directly with the client.
- Experience with AWS, Docker, and CI/CD.
- Experience with Auth0 or an equivalent OIDC identity provider.
- Strong experience in claude code or any other agent like cursor.
- Security-first mindset: multi-tenant authorization and secret management.
- Hangfire experience for jobs and queues.
- Advanced English (written and spoken).

Nice to have

- Experience with Redshift / Npgsql.
- Experience with the OpenAI API.
- Experience with SendGrid.
- Experience with Sentry.
- SQL Server performance tuning on large tables (~1.7M rows).

Soft Skills

- Strong ownership and autonomy to drive a project.
- Leadership to act as the project lead.
- Clear communication to interface directly with the client as their technical point of contact.

📌 Senior Backend Engineer (Argentina)
🏢 LoopStudio
📍 Argentina