Backend .NET Engineer — AWS & AI (Hybrid, Kraków)

Cornerstone OnDemand; Kraków; Hybrid; PLN 121,000 - 193,000; Full time

Job summary

Cornerstone OnDemand is seeking a Software Engineer .NET to join our hybrid Kraków team. You will design, develop, and maintain backend services and APIs in C#/.NET Core, deployed on AWS, while also contributing to frontend work with React or Angular.

You'll own features end-to-end, optimize SQL queries, and participate in CI/CD. The role emphasizes collaboration across QA, product, IT security, and release management, with a focus on scalable cloud-native solutions and AI-powered capabilities.

Qualifications

• 1–2 years of professional software development experience with C# and .NET.
• Experience designing and consuming RESTful APIs.
• Strong SQL skills with SQL Server (data modeling, joins, indexing, query optimization).
• Experience deploying workloads on AWS and familiarity with multiple services.

Responsibilities

• Design, develop, and maintain backend services and RESTful APIs in C#/.NET Core, deployed on AWS.
• Write, review, and optimize SQL and diagnose performance via execution plans.
• Build and deploy cloud-native components on AWS (Lambda, ECS/Fargate, API Gateway, S3, RDS).
• Develop front-end features with React or Angular and integrate with backend APIs.
• Own delivery of features end-to-end: design, implementation, tests, review, and CI/CD deployment.
• Monitor, debug, and improve performance, security, and reliability including production support.
• Investigate issues, perform root-cause analysis, and implement durable fixes.
• Participate in agile ceremonies, estimation, design reviews, and peer code reviews.
• Develop and integrate AI-powered features using AWS Bedrock and LLM frameworks.

Skills

C#/.NET

SQL

AWS

REST APIs

React/Angular

Git workflows

CI/CD

AI/LLMs

Education

BSc in CS/Engineering

Tools

Entity Framework Core

Dapper

Docker

CloudFormation/CDK/Terraform

Kubernetes

DynamoDB

Job description

Cornerstone OnDemand is seeking a Software Engineer .NET to join our hybrid Kraków team. You will design, develop, and maintain backend services and APIs in C#/.NET Core, deployed on AWS, while also contributing to frontend work with React or Angular.

You'll own features end-to-end, optimize SQL queries, and participate in CI/CD. The role emphasizes collaboration across QA, product, IT security, and release management, with a focus on scalable cloud-native solutions and AI-powered capabilities.