Senior Full Stack Engineer (Python / React / Temporal)

About the Opportunity

Some engineering roles ask you to build features. This one asks you to build the platform.

We’re assembling a brand-new engineering team responsible for creating the foundations of an Agentic Case Management platform-combining intelligent backend services with modern user experiences that enable the next generation of AI-powered applications.

If you’re passionate about building products end-to-end, enjoy owning both backend and frontend challenges, and want to help shape a platform from day one, we’d love to hear from you.

What You’ll Be Building

As a Senior Full Stack Engineer, you’ll help design and deliver the core building blocks of an Agentic AI platform.

You’ll develop scalable Python/FastAPI microservices alongside modern React applications, orchestrated through Temporal workflows and running on Microsoft Azure.

You’ll work on greenfield solutions where architecture, engineering quality, and product thinking matter just as much as writing code.

Responsibilities

• Design and develop scalable backend services using Python and FastAPI.
• Build modern frontend applications using React.
• Design robust APIs consumed by internal and external applications.
• Implement long-running workflows using Temporal.
• Collaborate closely with architects and product stakeholders.
• Contribute to architecture and technical design decisions.
• Develop reusable components across backend and frontend.
• Ensure performance, maintainability, and scalability.
• Deliver production-ready software in short iterative cycles.
• Leverage GenAI development tools to improve delivery quality and speed.

Requirements

Required

• Strong experience with Python.
• Solid experience building APIs using FastAPI.
• Strong React development experience.
• Experience building modern microservice architectures.
• Experience working with Azure.
• Strong understanding of REST APIs.
• Experience with distributed systems.
• Good software architecture skills.
• Experience with Git and CI/CD.
• Excellent communication skills in English.

Highly Desirable

• Temporal.
• Event-driven architecture.
• Azure APIM.
• Azure OpenAI.
• Docker & Kubernetes.
• AI Agents.
• Microservice orchestration.

Our Engineering Culture

We’re looking for engineers who enjoy building products-not simply delivering tickets.

You’ll work in an environment where ownership is encouraged, architecture discussions are open, and modern AI tooling is part of everyday engineering.

Cursor, Claude Code, OpenAI Codex, and similar tools are considered accelerators that help experienced engineers deliver faster while maintaining full accountability for the final product.

Why Join This Team?

You’ll have the opportunity to:

• Join a brand-new engineering team.
• Shape an AI platform from the ground up.
• Work across backend and frontend.
• Build products using modern AI technologies.
• Influence architecture and engineering standards.
• Deliver meaningful solutions instead of maintaining legacy systems.

We Offer

• Relocation package
• Competitive compensation packages
• Performance bonuses
• Flexible working hours
• Job rotation
• Learning through Arnia Academy
• Attractive projects
• Trainings
• International work experience
• Referral program
• Medical benefits

About the Company

At Arnia, we are a diverse and passionate team of software development engineers, quality assurance engineers, business analysts, system administrators, and managers, united by our shared dedication to creating high-quality software solutions and delivering exceptional services to our valued customers and partners.

We believe in customer satisfaction as being the single most important goal we want to achieve in everything we do. But we also believe that we can reach this goal while having fun at work, making friends, and enjoying working together. We have game evenings, nights out, and team building events to help us know each other better and spend quality time together. Also, we have a flat organization, with no unnecessary hierarchies and where you reach the management easily.

In Arnia you will meet very skilled software engineers with rich academic backgrounds, with passion for innovation and continuous education, self-driven and oriented toward results. At the same time, they are people with a high sense of humor, fun and informal, that value friendship, trust, and a nice working environment.

Excellence is achieved step by step, it is a journey we always take together as a team and as a modern organization.

We recognize the value of each individual, we value diversity, and we support your development career – your success is our success! We take pride in helping our people to develop their career, continuously improving their skills and their technical knowledge, and to fully reach their own development goals.

People are different, they are coming from various cultures and are motivated by different things:

• The financial interests
• The career development plan
• The technologies and the projects
• The work-life balance
• The opportunities to travel abroad

Why Arnia?

We recognize people’s diversity and we try to meet everyone’s goals.

• Game Evenings
• Nights Out
• Team Buildings
• Trainings

Arnia encourages you to pursue your own interests, projects, and ideas – passion can turn small things into big things – we want to be part of your own individual success. Let us know your ideas and your personal interests, and we will find a way to support you.

Relocation Package

Competitive Compensation Packages

Flexible Working Hours

Job Rotation

Performance Bonuses

Medical Benefits

Not the least, we have class A offices, located in Piata Victoriei – Europa House building, next to the metro stations and to other transportation means. It is very easy to get to work, and you will enjoy the quality and the lifestyle of our offices.

Attractive Projects

International Work Experience

Referral Program

Learning Through Arnia Academy

And if you like all these, why don’t you join us?

Recruitment Process

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Thank you for your interest in our internship program

We are sorry to inform you that we do not have any internships available at the moment. Please check back later for updates on our future opportunities.

Are you looking for a job and it doesn’t seem to be on our job openings list?

Don’t panic! You can send us your resume, and we’ll get back to you!

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Arnia Software has consolidated its position as a preferred IT outsourcing company in Romania and Eastern Europe, due to its excellent timely delivery and amazing development team.

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