Senior Software Engineer (all genders)

Permanent employee, Full-time · Zagreb / HR

About the job

Position Overview
We are looking for a Senior Backend Developer with extensive experience in building scalable microservices architectures. You'll be part of an innovative team developing and operating a global communication platform.

About the Role
Responsibilities

Develop and maintain backend services in Python with a focus on performance and scalability
Design and implement microservices for a high-frequency communication platform
Work closely with DevOps and Operations teams to ensure reliable infrastructure
Handle complex requirements: emails, SMS, voice calls, video conferencing in a distributed architecture
Maintain and evolve Python legacy code
Actively shape the technological future by evaluating new tools and integrating AI technologies

You

Requirements
Must-Have

Several years of experience as a Backend Developer with Python
Strong expertise in FastAPI and asynchronous programming (async/await)
Solid understanding of microservices architecture and REST APIs
Experience with at least one of the following databases: MongoDB or MariaDB/MySQL
Proficiency in Authentication & Authorization (OAuth2, JWT)
Docker experience for containerization
Version control with Git (preferably GitLab)
Fluent English for working in international teams

Highly Desirable

Experience with Message Brokers (RabbitMQ, Kafka)
Knowledge of Caching Systems (Redis)
Experience with Kubernetes and container orchestration
Familiarity with CI/CD pipelines (GitLab CI)
Monitoring & Observability tools (Kibana, Sentry, Grafana)
WebSocket implementation
Pydantic for data validation

Nice-to-Have

Experience with Provider APIs (Twilio, Vonage, Sinch, Infobip)
TTS integration (Azure, Acapela)
Basic knowledge of Keycloak or other IAM systems
Frontend basics (Preact, React) for better cross-team collaboration
Experience with legacy code modernization
Interest in AI/ML technologies and their practical applications

Tech Stack
Core Technologies
Python, FastAPI, Pydantic, Async/Await, Microservices, REST APIs, OAuth2, JWT, WebSockets

Database & Messaging
MongoDB, MariaDB, RabbitMQ, Redis

DevOps & Tooling
Docker, Kubernetes, Rancher, GitLab CI, Kibana, Sentry, Grafana

The Product
We are building a unified communication platformfor customer-facing interactions. The solution integrates multiple communication channels in a highly scalable architecture:

Email
SMS
Voice Calls
Conference Calls
Video Conferencing

The platform processes millions of transactions daily and requires the highest standards of reliability and performance.

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About us

What we do:

F24 is Europe’s leading Software-as-a-Service (SaaS) provider for resilience. More than 5,500 customers worldwide rely on F24’s digital solutions, which support companies and organisations through all areas of resilience. Solutions cover business messaging and service notification, emergency and mass notification, incident and crisis management, as well as governance, risk and compliance.

F24 supports customers in virtually every sector ranging from energy, healthcare, industry, finance, IT, tourism and aviation to a wide variety of public organisations. Many years of international experience have made F24 experts in improving resilience with digital solutions.

The company was founded in 2000 in Munich, where F24 AG’s head office is still located. Today, F24 supports companies and organisations in more than one hundred countries, via more than 20 locations in Europe and beyond. The F24 AG Board of Directors consists of F24 co-founder Christian Götz and the spokesperson Dr. Jörg Rahmer.

Find out more about working at F24 here.

Good reasons to work at F24:

Have a tangible impact! Work in an agile environment where you make an important contribution to the success of our customers and the future of our company.
Become part of our established company with an inspiring culture, flat hierarchies and our open, honest, innovative and supportive team!
Grow with us: We are a company on the road to success, experiencing steady international growth. You have the opportunity to help shape our development.
Take advantage of our flexible working model: We rely on a combination of presence in our offices and work from home. This way we strengthen our team spirit and at the same time gives you the opportunity to achieve the best possible balance between private and professional life.

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Your application

Thank you for considering a career at F24. Please fill out the following form. In case you are experiencing problems with the document upload, mail your documents to jobs@f24.com.