Senior Python Backend Engineer (AI / LLM)

Ableneo; Wien; Hybrid; EUR 90,000 - 125,000; Full time

Benefits offered by this job

Engaging projects

Learning & development

Flexible hours / home office

Modern office environment

MultiSport card

Job summary

Ableneo, a technology-driven transformation partner, seeks a Senior Python Backend Engineer to build scalable backend services and AI-powered applications for the banking domain. You will design REST APIs with FastAPI, implement asynchronous processing, and integrate LLM-based workflows with external tools.

Collaboration with cross-functional teams and a strong focus on code quality are essential. Ideal candidates have hands-on Python (3.12+), experience in production-ready LLM solutions, and

Qualifications

• Proven experience with Python backend development.
• Hands-on with modern Python (3.12+) and asynchronous programming.
• Experience building REST APIs with FastAPI or similar.
• Knowledge of Pydantic or similar data validation.
• Experience writing automated tests with pytest.
• Practical experience deploying LLM-based applications.
• Understanding of agent orchestration and integration of LLMs with tools.
• Git and collaborative development workflows.
• Professional working proficiency in English.

Responsibilities

• Design, develop and maintain scalable backend services using Python.
• Build REST APIs and define API contracts with FastAPI.
• Implement asynchronous processing, data validation and automated testing.
• Develop LLM-powered functionalities and AI agents.
• Collaborate with cross-functional engineering teams and participate in code reviews.
• Contribute to CI/CD workflows and continuous improvement.

Skills

Python backend

Async programming

FastAPI

Pydantic

pytest

LLM applications

Agent orchestration

Git

English

Tools

Docker

Kubernetes

LangChain

LangGraph

Job description

Job description

We are looking for a Senior Python Backend Engineer (M/F) for our client in the banking sector. The role focuses on developing modern backend services and AI-powered applications, combining strong Python engineering skills with hands‑on experience in LLM-based solutions and agent orchestration.

Responsibilities

• Design, develop and maintain scalable backend services using Python.
• Build REST APIs and define API contracts using FastAPI or similar frameworks.
• Implement asynchronous processing, data validation and automated testing.
• Develop and integrate LLM-powered functionalities, AI agents and external tools.
• Work with knowledge sources and contribute to agent orchestration.
• Evaluate and improve the quality, reliability and performance of AI-generated outputs.
• Write clean, maintainable and well‑tested code.
• Participate in code reviews and collaborate with cross‑functional engineering teams.
• Contribute to CI/CD workflows and continuous improvement of development processes.

Requirements

• Strong hands‑on experience with Python backend development.
• Experience with modern Python (3.12+) and asynchronous programming.
• Experience building REST APIs using FastAPI or comparable frameworks.
• Knowledge of Pydantic or similar data validation frameworks.
• Experience writing automated tests, preferably using pytest.
• Practical experience with LLM-based applications delivered to production.
• Understanding of agent orchestration and integration of LLMs with external tools or knowledge sources.
• Experience with Git and collaborative development workflows.
• Professional working proficiency in English.

Nice to Have

• Experience with LangChain or LangGraph.
• Knowledge of prompt engineering and LLM evaluation techniques.
• Experience with Docker and Kubernetes.
• Familiarity with metrics, tracing and structured logging.
• Previous experience in banking, financial services or other regulated environments.

Benefits

• Engaging projects across diverse industries, offering continuous professional challenges and growth opportunities
• Tailor‑made learning & development program, complemented by monthly in‑house workshops to boost your skills
• Flexible working hours and the possibility of home office
• Modern, inspiring office environment with daily perks such as breakfast, fresh fruit, and yoga sessions
• MultiSport card to support an active lifestyle and access to a wide range of sports and wellness facilities

Company description

Who we are

Ableneo is a partner for AI and technology‑driven transformation. We combine deep software engineering with business consulting to help organisations implement intelligent systems that deliver measurable results and reduce the risk of failed innovation.

What we do

AI & Data Enabling. We deploy chatbots and LLM solutions, automate documents and workflows, and work with Computer Vision. Our focus is on solving concrete business problems with AI and achieving a high success rate in real use cases.

Business Optimisation & Efficiency. We streamline processes, reduce delays, automate operational work, and set up more efficient ways of working.

Product Design & Development. We design and build digital products, customer journeys, and scalable platforms that support long‑term growth.

Software Engineering. We offer flexible delivery models. From specialised roles to full teams, supporting both fast‑growing companies and established enterprises.

Why join us

We have years of experience and strong references across startups, scale‑ups, and large organisations. We work on assignments where AI makes real impact. For example, in the banking sector we validated an LLM solution with a high success rate in a real proof‑of‑concept.

At Ableneo you will work on projects that push the boundaries of AI and software engineering. You will solve complex problems, collaborate with decision‑makers, and help build systems that have immediate business value.

If you want to shape the next generation of intelligent software, let’s talk.