Software Engineer .NET

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

Job summary

Cornerstone Research is seeking a Software Engineer with 1–2 years of professional experience to design, build, and maintain cloud-native backend services in C#/.NET Core, deployed on AWS. You will also contribute to frontend work in React or Angular and integrate AI-enabled features into production systems.

The role emphasizes delivering well-structured APIs, robust data access via SQL Server, and collaborating across teams to ensure reliable, scalable software.

Qualifications

• 1–2 years of professional software development experience building applications in C#/.NET.
• Demonstrated experience designing and consuming RESTful APIs.
• Strong SQL skills against SQL Server: data modeling, joins, stored procedures, indexing, and query optimization.
• Hands-on experience deploying or operating workloads on AWS.
• Solid grasp of object-oriented design, SOLID principles, and common design patterns.
• Working experience with a modern front-end framework such as React or Angular, plus HTML/CSS/JS basics.

Responsibilities

• Design, develop, and maintain backend services and RESTful APIs in C# / .NET Core, deployed on AWS.
• Write, review, and optimize SQL — queries, stored procedures, views, and schema changes.
• Build and deploy cloud-native components on AWS using Lambda, ECS/Fargate, API Gateway, S3, RDS, and CloudWatch.
• Develop front-end features using React or Angular and integrate with backend APIs.
• Own delivery of assigned features end to end: design input, implementation, tests, review, deployment via CI/CD.
• Monitor, debug, and improve application performance, security, and reliability.
• Investigate issues, perform root cause analysis, implement durable fixes.
• Participate in agile ceremonies, contribute to estimations and design reviews.
• Develop and integrate AI-powered features using AWS Bedrock and LLM frameworks.
• Collaborate with QA, product, operations, IT security, and release management.

Skills

C#/.NET

REST APIs

SQL Server

AWS

React/Angular

Git workflows

Unit testing

Secure coding

Design patterns

AI basics

JavaScript/TypeScript

HTML/CSS

Education

Bachelor's degree in CS or related

Tools

AWS Lambda

S3

ECS/Fargate

API Gateway

RDS

DynamoDB

SQS/SNS

CloudFormation/CDK/Terraform

Job description

We're looking for a

Software Engineer .NET

This role is Hybrid,Krakow Office

This role is Hybrid in Krakow.

We are seeking a motivated Software Engineer with 1–2 years of professional experience building and shipping applications on the Microsoft .NET stack, relational databases, and AWS. You will join a team that builds cloud-based web applications and services, and you will own features from design discussion through deployment and production support.

You will work primarily in C# and .NET Core building backend services and APIs, write and tune SQL against SQL Server, and deploy and operate workloads on AWS. You will also contribute to our front end, built with modern JavaScript frameworks such as React or Angular, and to AI-enabled features built on Generative AI and Large Language Models.

The ideal candidate has already delivered production code, is comfortable owning a well-scoped feature with light oversight, debugs problems methodically, and is curious about applying emerging AI capabilities to real products.

In This Role You Will...

• Design, develop, and maintain backend services and RESTful APIs in C# / .NET Core, deployed on AWS.
• Write, review, and optimize SQL — queries, stored procedures, views, and schema changes — and diagnose performance issues through execution plans and indexing.
• Build and deploy cloud-native components on AWS using services such as Lambda, ECS/Fargate, API Gateway, S3, RDS, and CloudWatch.
• Develop front-end features using React, Angular, or a comparable modern framework, and integrate them with backend APIs.
• Own delivery of assigned features end to end: technical design input, implementation, unit and integration tests, code review, and deployment through CI/CD.
• Monitor, debug, and improve application performance, security, and reliability, including participation in production support and incident triage.
• Investigate functional and technical issues, drive root cause analysis, and implement durable fixes rather than symptom patches.
• Participate actively in agile ceremonies, contribute to estimation and technical design reviews, and give constructive feedback in peer code reviews.
• Develop and integrate AI-powered features using services such as AWS Bedrock and modern LLM frameworks.
• Collaborate across QA, product, operations, IT security, and release management, and communicate status and risks proactively.

You Have Got What it Takes If you Have...

Bachelor's degree in Computer Science, Engineering, or a related field, or equivalent practical experience.

• 1–2 years of professional software development experience building applications in C# and .NET (.NET Core / .NET 6+ or .NET Framework).
• Demonstrated experience designing and consuming RESTful APIs.
• Strong SQL skills against a relational database such as SQL Server: data modeling, joins, stored procedures, indexing, and query optimization.
• Hands-on experience deploying or operating workloads on AWS, with working knowledge of at least three commonly used services.
• Solid grasp of object-oriented design, SOLID principles, and common design patterns, with the judgment to know when to apply them.
• Working experience with a modern front-end framework such as React or Angular, along with strong HTML, CSS, and JavaScript/TypeScript fundamentals.
• Experience with Git-based workflows, branching strategies, and pull request review.
• Experience writing automated unit tests with xUnit, NUnit, or MSTest.
• Understanding of secure coding practices and awareness of common vulnerability classes such as those in the OWASP Top 10.
• Foundational knowledge of AI, Generative AI, and LLMs, including prompt engineering and practical applications in software development.
• Strong analytical and problem-solving skills, and clear written and verbal communication.

Preferred Qualifications

• Experience with Entity Framework Core, Dapper, or another ORM, and proficiency with LINQ.
• Hands-on experience with AWS Lambda, S3, ECS/Fargate, API Gateway, RDS, DynamoDB, SQS/SNS, IAM, or infrastructure-as-code (CloudFormation, CDK, or Terraform).
• Experience building or maintaining microservices and containerized applications with Docker.
• Experience with CI/CD pipelines such as Azure DevOps, GitHub Actions, AWS CodePipeline, or Jenkins.
• Familiarity with NoSQL or caching technologies such as DynamoDB, MongoDB, or Redis.
• Experience integrating LLM or AI capabilities into an application using AWS Bedrock, Azure OpenAI, Semantic Kernel, or LangChain.
• Working knowledge of Python, particularly for AI or data-related tasks.
• Experience in an Agile or Scrum environment with regular production releases.
• Interest in user experience, accessibility, and responsive web design.
• AWS certification (Developer Associate or Solutions Architect Associate) or a relevant Microsoft certification.
• Experience with component libraries, state management, or front-end testing tools in the React or Angular ecosystem.

Our Culture:

Spark Greatness. Shatter Boundaries. Share Success. Are you ready? Because here, right now – is where the future of work is happening. Where curious disruptors and change innovators like you are helping communities and customers enable everyone – anywhere – to learn, grow and advance. To be better tomorrow than they are today.

Who We Are:

Cornerstone powers the potential of organizations and their people to thrive in a changing world. Cornerstone Galaxy, the complete AI-powered workforce agility platform, meets organizations where they are. With Galaxy, organizations can identify skills gaps and development opportunities, retain and engage top talent, and provide multimodal learning experiences to meet the diverse needs of the modern workforce. More than 7,000 organizations and 100 million+ users in 180+ countries and in nearly 50 languages use Cornerstone Galaxy to build high-performing, future-ready organizations and people today.

Total Rewards:

At Cornerstone, we are dedicated to inspiring excellence and pushing boundaries in everything we do. Our compensation strategy is based on three fundamental principles: equitable pay, market-driven research, and skill-based appraisals. As part of our mission to share success and empower individuals to thrive in an ever-changing world, the listed salary range is just one element of Cornerstone’s comprehensive compensation package. This compensation package may also include annual bonuses, short- and program-specific awards depending on the role, and a comprehensive benefit offering. The disclosed salary range reflects the geographic differential based on the location of the position if applicable. The starting salary for the successful applicant will depend on several job-related factors, including education, training, experience, certifications, location, business needs, and market demands. This range is based on a full-time position and may be adjusted in the future. Join us in shaping the future of work — tomorrow, together. Experience flexibility and empowerment in your career at Cornerstone. The BASE salary range for this position is: 120800 - 193300 PLN.

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