Junior Site Reliability Engineer

Cosmose, Inc.; Warszawa; On-site; PLN 120,000 - 180,000; Full time

Job summary

Cosmose AI is seeking a Junior Site Reliability Engineer to help build reliable infrastructure and automation for AI-driven content solutions. You will contribute to performance optimization, security improvements, and cross-cloud networking across regions.

Join a startup‑style engineering team with a strong growth trajectory. The role emphasizes collaboration, proactive problem solving, and continuous learning in a fast-paced environment.

Qualifications

• Solid understanding of Linux operating systems.
• Programming skills, particularly in Python.
• Experience in managing a Linux-based server.
• Conceptual understanding of orchestration tools such as Kubernetes.
• Collaborative mindset with excellent problem-solving and detail orientation.
• Good communication in Polish and English.

Responsibilities

• Automate routine tasks and develop tools to reduce manual work.
• Optimize system performance and ensure reliability and scalability.
• Enhance security with automated checks and vulnerability scanning.
• Operate a cross-cloud network across multiple providers and regions.

Skills

Python

Linux

Kubernetes

Prometheus

Nginx

HAProxy

AWS

Jenkins

Ansible

Terraform

Tools

AWS

Prometheus

Grafana

HAProxy

Nginx

Jenkins

Ansible

Terraform

Redis

Postgres

Clickhouse

Kafka

RabbitMQ

Job description

About Cosmose AI

Unicorn Foundations: At Cosmose AI, we’re building smart, innovative technology that’s redefining digital marketing and content distribution. Since launching in 2014, we’ve gone from transforming offline shopping to powering personalized content experiences through AI. Founded by Miron Mironiuk, our journey began with one bold idea - and it has grown into a feature that caters to what people care about most, right from their lock screens.

Exceptional Engineering: Our engineering team is far from average; it's a powerhouse of talent. Comprising former FAANG employees and programming champions, they bring deep expertise and a shared commitment to building world‑class products. Our strength lies in engineering solutions that leverage the power of AI, Data, and distributed computing. We thrive in a fast‑paced startup environment, where agility, creativity, and quality drive everything we do.

Global Presence, Local Innovation: Cosmose AI is a global company with a presence in 8 countries, transforming content engagement through cutting‑edge technology. Our flagship product, KAIKAI Lock Screen, delivers AI‑powered, personalized content to users worldwide, unlocking new and exciting opportunities for product placement.

We are looking for a Junior Site Reliability Engineer to join our engineering team. In this role, you will contribute to building reliable infrastructure, optimizing performance, and automating processes to support our innovative, AI‑driven solutions. If you’re passionate about automation, optimizing performance, and ensuring system scalability, we’d love to have you on board!

TL;DR Why us

• Big Scale & Startup Culture: Join a company that combines the scale of a major player with the agility and innovation of a startup
• Exceptional Team: Collaborate with a team of former employees from tech giants like Google, Meta, ByteDance, and Microsoft, as well as ACM ICPC programming champions
• Stock Options: As we grow and succeed together, you'll have the chance to benefit from it
• Flat Structure: Enjoy a flat organizational structure that promotes collaboration and provides opportunities to learn from seasoned technical leadership

Responsibilities

• Automate Routine Tasks: Develop tools to automate administrative tasks, reducing manual intervention and improving efficiency.
• Optimize System Performance: Create automated solutions to monitor and maintain system performance, ensuring reliability and scalability.
• Enhance Security: Develop and deploy automated security measures, vulnerability scans, and compliance checks to protect our infrastructure and data.
• Operate a Cross‑Cloud Network: Monitor, troubleshoot, and expand an overlay network spanning multiple cloud providers and continents, ensuring performant and reliable connectivity.

Technologies Used

• Cloud: AWS
• Operating systems: Linux
• Programming: Python
• Orchestration: Kubernetes, Helm
• Monitoring and alerting: Prometheus, Grafana, VictoriaMetrics
• HTTP server: HAProxy, Nginx
• CI&CD: Jenkins, Ansible
• Databases: Redis, Postgres, Clickhouse
• Message Queues: Kafka, RabbitMQ
• IaC: Terraform

Requirements

• Solid understanding of Linux operating systems
• Programming skills, particularly in Python
• Experience in managing a Linux‑ or Unix‑based server
• Conceptual understanding of orchestration tools such as Kubernetes
• A collaborative mindset with excellent problem‑solving skills and attention to detail
• Good communication within the team (Polish and English are required)

Nice to Have

• Knowledge of monitoring tools like Prometheus and Grafana.
• Practical experience with cloud platforms like AWS
• Familiarity with infrastructure as code (IaC) tools like Terraform.
• Experience with CI/CD pipelines

What You’ll Enjoy

Cosmose provides employees with a great platform to immerse and learn about the most exciting, innovative, and disruptive technologies in offline behavior solutions. We are unveiling untapped opportunities and profits in the industry - and we’re just getting started. At the core of our constant innovation is a rockstar engineering team, including four world championship programming medalists, working alongside driven, curious minds across all departments. You’ll work with a seasoned leadership team, backed with expertise across strategic domains - all within a culture that values learning, impact, and cross‑functional collaboration. Cosmose is where a strong culture and shared goals unite individuals and teams to achieve bold milestones together.

We’re building something big - and we’re just getting started.

Additional Information

If you’re excited about shaping the future of AI‑powered mobile content and working with a team that’s pushing boundaries, we’d love to meet you.

Be part of the Cosmose story. Apply now!

Read More On

TechCrunch, Business Insider