Senior .NET Backend Engineer — Payments & AI-Enabled Systems

FullStack; Concepcion; On-site; CLP 25,000,000 - 50,000,000; Full time

Job summary

FullStack is seeking a Senior Backend Engineer to join our talent network and work on production-grade .NET systems with focus on reconciliation or transaction-matching workflows. You will collaborate daily with client teams, designers, and engineers to deliver robust backend solutions and leverage AI tooling to accelerate development.

Required 5+ years of software development, advanced English, a 4-year degree, and experience with C#/.NET, PostgreSQL, and cloud services (AWS/Azure).

Qualifications

• 5+ years of professional software development experience.
• Advanced English is required.
• Successful completion of a four-year college degree is required.
• Has engineered, deployed, and maintained backend systems using C# and the .NET framework.
• Has designed schemas, handled transactions, and maintained strict decimal precision in PostgreSQL.
• Has working knowledge of double-entry accounting, subledgers and GL integration.
• Has built idempotent, re-playable data ingestion pipelines for BAI2, ACH, or other payment rails.
• Has built internal tooling or exception resolution interfaces using React and TypeScript.
• Has deployed services on AWS and integrated them with existing Azure cloud infrastructure.
• Uses AI coding agents daily to accelerate planning, building, and testing of production software.
• Experience shipping production AI/LLM features is a plus.
• Experience with high-volume bill pay, FBO accounts, chargebacks, or DBA-reviewed database workflows is a plus.
• Experience with SQL Server and observability tools like Datadog is a plus.
• Available to work with significant overlap with U.S. Mountain Time business hours.
• Ability to work through new and difficult issues and contribute to libraries as needed.

Responsibilities

• Join our talent network and connect with U.S. clients for flexible, project-based development work as a Senior Backend Engineer working with .NET and production reconciliation or transaction-matching systems.
• You will integrate directly into our client's team and work alongside their existing designers and engineers on a daily basis.

Skills

Advanced English

Backend development

C# /.NET

SQL / DB design

Data pipelines

AI coding agents

Problem solving

Team collaboration

Education

Bachelor's degree in CS or related field

Tools

React

TypeScript

PostgreSQL

SQL Server

AWS

Azure

Datadog

Job description

FullStack is seeking a Senior Backend Engineer to join our talent network and work on production-grade .NET systems with focus on reconciliation or transaction-matching workflows. You will collaborate daily with client teams, designers, and engineers to deliver robust backend solutions and leverage AI tooling to accelerate development.

Required 5+ years of software development, advanced English, a 4-year degree, and experience with C#/.NET, PostgreSQL, and cloud services (AWS/Azure).