Back End Developer (AI Infrastructure)

Alignerr; Kraków; On-site; PLN 96,000 - 152,000; Full time

Job summary

Alignerr is seeking a Back End Developer to design, build, and optimize server-side systems and APIs powering AI products—from data pipelines to scalable microservices. This is a fully remote contract role enabling you to contribute to global AI infrastructure from anywhere.

You’ll work with Python/Go/Java/Node.js, databases, and cloud platforms, delivering robust, well-documented code and collaborating with distributed teams on architecture decisions.

Qualifications

• Proficient in one or more back end languages such as Python, Go, Java, Node.js, or Rust.
• Strong understanding of RESTful API design and microservices.
• Experience with relational and/or NoSQL databases.
• Comfortable with cloud platforms and containerization.
• Familiar with Git, CI/CD, and distributed teams working asynchronously.

Responsibilities

• Design, develop, and maintain robust back end services and data pipelines.
• Build scalable server-side architecture to support AI workloads.
• Write clean, documented, and testable code following best practices.
• Integrate with databases, queues, cloud services, and third-party APIs.
• Optimize performance, reliability, and scalability as usage grows.
• Collaborate asynchronously with distributed teams and iterate on architecture.
• Troubleshoot production issues and participate in code reviews.
• Work independently on task-based and project-based assignments.

Skills

Backend languages

RESTful APIs

Distributed systems

Git & CI/CD

Docker & Kubernetes

Cloud platforms

Tools

PostgreSQL

MongoDB

Redis

AWS

GCP

Azure

Job description

About The Role

What if the code you write could directly power the AI systems shaping how millions of people interact with technology? We’re looking for Back End Developers in Kraków to design, build, and optimize the server-side systems and APIs that drive cutting-edge AI products — from data pipelines and model-serving infrastructure to scalable microservices that handle real-world traffic at scale.

Kraków has earned its reputation as one of Central Europe’s premier tech destinations. This is a fully remote, flexible contract role that lets you contribute to globally impactful AI infrastructure from right where you are.

• Organization: Alignerr
• Type: Hourly Contract
• Location: Remote
• Commitment: 10–40 hours/week

What You’ll Do

• Design, develop, and maintain robust back end services, APIs, and data pipelines
• Build scalable, high-performance server-side architecture to support AI training and inference workloads
• Write clean, well-documented, and testable code following engineering best practices
• Integrate with databases, message queues, cloud services, and third-party APIs
• Optimize system performance, reliability, and scalability as usage grows
• Collaborate asynchronously with distributed teams of engineers, researchers, and product leads
• Troubleshoot production issues, conduct code reviews, and contribute to architectural decisions
• Work independently on task-based and project-based assignments on your own schedule

Who You Are

• Proficient in one or more back end languages — Python, Go, Java, Node.js, Rust, or similar
• Solid understanding of RESTful API design, microservices architecture, and distributed systems
• Experienced with relational and/or NoSQL databases (PostgreSQL, MongoDB, Redis, etc.)
• Comfortable working with cloud platforms such as AWS, GCP, or Azure
• Familiar with version control (Git), CI/CD pipelines, and containerization (Docker, Kubernetes)
• Strong problem-solving skills and the ability to debug complex systems independently
• Self-motivated, reliable, and effective when working asynchronously without close supervision
• Clear communicator who can document decisions and collaborate across time zones

Nice to Have

• Experience building infrastructure for machine learning or AI systems
• Familiarity with data processing frameworks (Apache Kafka, Spark, Airflow, or similar)
• Background in performance optimization, caching strategies, or high-throughput systems
• Knowledge of authentication, authorization, and security best practices
• Experience with serverless architectures or event-driven design patterns
• Contributions to open-source projects or a strong portfolio of personal/professional work

Why Join Us

• Work on cutting-edge AI infrastructure projects alongside leading research labs
• Fully remote and flexible — set your own hours and work from anywhere
• Freelance autonomy with access to meaningful, technically challenging work
• Build systems at the intersection of software engineering and artificial intelligence
• Collaborate with a global network of talented engineers and researchers
• Potential for ongoing work and contract extension as new projects launch