Backend Developer

Engagement Type: Independent External Consultant - B2B Contract

Mandatory Requirement: Applicants must already have an active, registered sole proprietorship (ατομική επιχείρηση) in Greece and be able to issue invoices for their professional services.

Please note: This is strictly an external consulting opportunity, not a salaried employment position. Applications from candidates who do not already meet the above business registration requirement will not be considered.

About the Role

At AI2CYBER, we are seeking a highly motivated and experienced Senior Backend Developer (Python) to collaborate with our engineering team as an independent external consultant based in Greece.
The ideal candidate will have strong expertise in Python, API development, databases, data processing, and backend architecture.

The role focuses on developing reliable backend services, scalable APIs, data ingestion mechanisms, processing workflows, automation features, and core platform logic for advanced enterprise software products.

The selected consultant will contribute to systems that handle complex technical data, integrate with multiple sources, support operational workflows, and require strong attention to reliability, security, maintainability, and performance.

Responsibilities

• Design, develop, and maintain backend services using Python.
• Build clean, stable, and well-documented REST APIs.
• Develop data ingestion, normalization, enrichment, and processing workflows.
• Work with structured and unstructured technical datasets from internal and external sources.
• Design and maintain database schemas, indexes, queries, and backend data models.
• Implement background workers, scheduled tasks, automation pipelines, and long-running processing jobs.
• Work with PostgreSQL, Redis, object storage, and other backend infrastructure components.
• Implement authentication, authorization, API access controls, rate limiting, and audit-friendly backend logic.
• Build backend support for analytics, reporting, monitoring, workflow automation, and user-facing platform features.
• Collaborate closely with frontend developers to define API contracts and deliver reliable data to the user interface.
• Improve backend performance, error handling, logging, and observability.
• Participate in code reviews, testing, debugging, deployment preparation, and technical documentation.
• Handle proprietary technical information with discretion and professional confidentiality.

Required Technical Skills

• At least 5 years of professional backend development experience.
• Strong experience with Python.
• Experience with Flask, FastAPI, or Django.
• Solid understanding of REST API design.
• Experience with PostgreSQL.
• Strong SQL skills and understanding of database design.
• Experience with Docker and Linux environments.
• Experience with Git and collaborative development workflows.
• Understanding of authentication, JWT, RBAC, and API security principles.
• Experience with background jobs, workers, queues, schedulers, Redis, Celery, or similar technologies.
• Ability to write clean, modular, testable, and maintainable backend code.
• Strong debugging skills in development and production-like environments.
• Ability to understand complex business logic and translate it into reliable backend services.

Nice to Have

• Experience with SQLAlchemy or similar ORM frameworks.
• Experience with large-scale data processing, parsing, enrichment, or data quality workflows.
• Experience with asynchronous processing and event-driven backend design.
• Experience with search, indexing, graph, or analytics-oriented databases.
• Experience with cloud services, containerized deployments, and CI/CD pipelines.
• Experience with monitoring, logging, metrics, and observability tools.
• Experience building backend systems for enterprise platforms, technical analytics, monitoring, compliance, intelligence, or operational decision-support products.
• Experience with secure coding and secure-by-design backend architecture.
• Familiarity with AI-assisted processing or LLM integrations is a plus.

Technology Stack

Python, Flask/FastAPI, PostgreSQL, SQLAlchemy, Redis, Celery, Docker, Linux, Git, REST APIs, JWT, RBAC, background workers, schedulers, external API integrations.

Ideal Candidate Profile

The ideal candidate is not just someone who writes endpoints. We are looking for a backend developer who understands data flows, system reliability, security requirements, performance constraints, and production-quality engineering.

This role is suitable for someone who can build the core engine of a serious software product and take ownership of backend components from design to implementation.

Confidentiality Note

The selected candidate will work on proprietary backend systems and sensitive product logic. Detailed product information, data flows, and internal architecture will be shared only with shortlisted candidates and, where appropriate, under confidentiality terms.

Benefits

• Fully remote collaboration from anywhere in Greece.
• Competitive consulting fees, subject to periodic review.
• Work on advanced backend systems with real technical depth.
• Opportunity to build core platform components, not just minor features.
• Exposure to data processing, automation, analytics, monitoring, and secure software engineering.
• A demanding but rewarding technical environment.
• Space to take ownership and contribute to long-term product architecture.
• Personal and professional development, amongst industry experts and talented people.

External Consulting Requirements - Important

This opportunity is exclusively available to independent professionals operating through an existing sole proprietorship in Greece.

To be eligible, applicants must:

• Already have an active, legally registered sole proprietorship (ατομική επιχείρηση) in Greece at the time of application.
• Be legally able to provide professional software development and IT consulting services.
• Be able to issue valid invoices for the services provided.
• Be available to enter into a B2B consulting agreement with AI2CYBER.

This is not an employee position, and no salaried employment contract will be offered. Establishing a sole proprietorship after selection does not satisfy the eligibility requirements.

About AI2CYBER

At AI2CYBER, we are a cybersecurity firm dedicated to providing cutting-edge solutions to protect businesses and individuals from evolving cyber threats. Our mission is to empower organisations to navigate the complex cybersecurity landscape with confidence. We believe that by combining robust security solutions, continuous improvement, and a proactive mindset, we can help our clients stay one step ahead of cyber attackers. We are committed to building a safer digital world and are passionate about making a positive impact in the industry.

Interested in Collaborating With Us?

If you are an experienced Backend Developer with a passion for building sophisticated software solutions, and you already operate an active sole proprietorship in Greece, we would be pleased to hear from you.

Please apply only if you meet the external consulting and business registration requirements outlined above.

To apply, please send us your CV at