AI and ML Engineer

Job title: AI and ML Engineer

Office location: Spanskih boraca, Belgrade - Hybrid working (3 days in the office)

About the role and the Team:

AI and ML Engineer will work closely with internal stakeholders, data engineers, product managers, and architects to design, build, and deploy AI/ML solutions that deliver measurable business impact — moving beyond experimentation into scalable, production-grade systems embedded in core products and processes. Responsible for the full ML lifecycle from experimentation and model development through to production deployment, monitoring, and continuous improvement, including large language model (LLM) integrations and agentic AI workflows.

What will you be doing?

• Design, train, validate, and deploy machine learning models across use cases. Integrate ML solutions into business systems (CRM, OSS, digital platforms, APIs) supporting both real-time and batch inference. Move models from experimentation into production via APIs, Kafka pipelines, and streaming architectures.
• Build and maintain MLOps pipelines covering CI/CD for models, versioning, deployment automation, and monitoring for model drift and performance degradation. Ensure reproducibility, traceability, and governance of models and experiments.
• Collaborate with Data Engineers to define scalable data pipelines and feature engineering logic.
• Design, implement, and operationalise AI pipelines including LLM integrations (API-based and self-hosted), retrievalaugmented generation (RAG) systems, embedding workflows, and agentic AI automation using frameworks such as LangChain, LlamaIndex, or CrewAI. Build reusable AI components and maintain model registries, prompt libraries, and evaluation datasets.
• Establish evaluation frameworks, observability tooling, and guardrails to measure model quality, latency, and cost. Adhere to responsible AI practices including bias mitigation, explainability, transparency, and data privacy and security standards. Own production monitoring and incident response for AI/ML systems.
• Partner with stakeholders to translate business problems into AI/ML solutions with clear success metrics. Champion AI/ML best practices across the engineering organisation; contribute to internal standards, frameworks, and reusable components; and mentor colleagues engaging with AI/ML capabilities.

What we are looking for:

• A bachelor's degree in Computer Science, Software Engineering, Mathematics, or a related field
• Previous experience in software or data engineering, withexpeirence in building, deploying, and operating ML models or AI systems in production
• Strong programming skills in Python (pandas, scikit-learn, PyTorch, or TensorFlow) and experience with data platforms (AWS, Spark, SQL). Knowledge of the full ML lifecycle: experimentation to deployment to monitoring. Experience with Kafka, APIs, microservices, and containerisation (Docker/Kubernetes).
• Hands-on experience with MLOps tooling (SageMaker, MLflow, or equivalent), orchestration tools (Airflow, or equivalent), CI/CD practices, and version control. Understanding of LLM frameworks (LangChain, LlamaIndex, or equivalent), prompt engineering, RAG architectures, and vector stores.
• Strong understanding of data modelling and feature engineering. Experience working with large-scale structured and unstructured data. Ability to connect ML/AI solutions to business outcomes and communicate complex concepts clearly to non-technical stakeholders.
• Experience with agentic AI frameworks (CrewAI, AutoGen, Claude Code, or equivalent), fine-tuning open-source models, or deep understanding of LLM evaluation and responsible AI governance practices is an advantage - DESIRABLE

Why work for us?

We're in your corner and our vision is to be the UK's most loved and desired broadband provider, that shows the way broadband is done!

Awarded Broadband Provider of the Year 2023 Uswitch Telecoms Awards, as voted for by 20,000 customers, plus Fair Terms Gold Award 2023. We're also very proud to have been awarded Great Place to Work Certification (2022-23) and UK's Best Workplaces for Wellbeing (2022).

In our Belgrade office, we work with our UK colleagues in a shared mission: to gigabit Britain. Our office started up in 2013 with what was then 20 developers, now we're more than 700 people. Do you want to be a part of our next adventure?

Going beyond the expected

Whatever we're doing – whether we're liaising with our customers, delivering our network, or working on our company strategy, going beyond the expected is the benchmark for everything we do. How we work is shaped by our three culture principles:

• We work smarter together
• We stay focused
• We strive for excellence

Some of our key Benefits:

• Competitive salary
• Global Remote working for up to 2 week per year for those who are able to work remotely
• 25 days' paid holiday increasing each year, to a max of 35
• Extra days off for your birthday, move house and volunteer
• Access to a wellbeing platform, Rezilient
• Partnership with SOS Children's Village
• Private medical insurance (Permanent employees)
• Fit Pass discount
• Technology discount
• Team sports activities
• Massages in the office
• Sweet Tuesdays

We're committed to providing equal opportunities to all applicants and employees. In fact, this is at the heart of our culture and values. We welcome applications from candidates from all walks of life.

What happens next?

1. You apply (please send us your CV in English)
2. We carefully review your application
3. We'll get back to you — even if it's a no (for now)