Vacant job

What will you do?

As an AI/ML Engineer at Rebtel, you will define how AI is implemented at Rebtel. This includes deciding on our standard tooling, how we evaluate models presented to real users, and what "good" looks like for our prompts and pipelines. AI is transitioning from a side project to the core of how Rebtel operates and what we deliver to our users. We are hiring the second engineer for our ML/AI subteam to help build classical ML for the business, LLM-powered systems for the product, and instill a clear production mindset across both.

You will sit within the Data team, report to our Head of Data, and partner with one other ML/AI engineer to shape this capability from the ground up.

Areas of ownership: You will own work across two complementary tracks and deliver in both.

Classical ML, in production, for operational leverage

• Risk and fraud models across payments, top-ups, and account behaviour

• Churn prediction and retention modelling on a user base of over a million

• Forecasting, pricing, segmentation, and the next batch of operational problems we haven't tackled yet

• End-to-end ownership of models: scoping with stakeholders, building, deploying, monitoring, and retraining

LLMs and AI agents, from internal automation to in-product features

• Start with our customer support agents and automations: RAG pipelines, prompt orchestration, tool-use, and evaluation harnesses

• Move LLM capability into the product as user-facing features

• Help guide the company on where AI actually creates leverage, what to build, what to buy, what to ignore, and turn good ideas into shipped systems

Requirements:

• You are an excellent communicator and collaborator. We work in English, but you will hear many languages in our Stockholm office

• 4+ years of hands-on ML engineering in Python, with real production ownership, not just notebooks

• Strong fundamentals in classical ML: feature engineering, model selection, validation, and the unglamorous parts of keeping a model healthy in production

• A genuine production mindset: monitoring, retraining, eval harnesses, CI/CD for models, and the instinct to debug when something drifts at 2 am

• Comfort working the whole loop: stakeholder scoping → data → model → deployment → measurement → iteration

• Strong written and spoken English, and the ability to translate between business problems and ML challenges

• Hands-on experience with LLM frameworks — LangChain, LangGraph, LlamaIndex, or equivalents

• Built RAG systems, agentic workflows, or LLM-backed products that real users (or real internal teams) actually used

• Comfortable with vector databases, embeddings, prompt evaluation, and measuring LLM systems with something more rigorous than "vibes"

• An obsession with staying up-to-date on developments in the AI space

• Experience with a major cloud provider (AWS / GCP / Azure), containers, and a modern data stack

• Experience with MLOps tooling: MLflow, Airflow, Kubernetes, and feature stores is a plus

• Background in fintech, payments, telecom, or other regulated/operational domains is a plus

Why Rebtel?

Rebtel has been connecting people across borders for nearly 20 years. Today, we are profitable, growing, and at a pivotal moment in our journey. As we enter our next phase, we are building an organisation designed for speed, ownership, and real impact, where every role contributes directly to shaping what comes next.

This is a place with global ambition and a strong foundation, where ideas move quickly and decisions matter. You won't get lost in layers of process or slow-moving structures. Instead, you'll find the space to take ownership, collaborate across teams, and make meaningful contributions from day one. Based in Stockholm, we bring together a diverse, international team united by a shared purpose: to simplify the way people connect worldwide.

At Rebtel, you are the most important asset, and we strive to provide a comprehensive package of benefits and perks that enhance your well-being and work experience. Here are some of the things you can expect from us:

• Pension Plan

• Health Checkups, Influenza shots, and Private Medical Insurance

• Dental Insurance

• Occupational Insurance

• Wellness allowance (5,000 SEK)

• Discount on gym memberships

• Bonus program

• Extra parental pay

• 30 days annual vacation

• Monday breakfasts

• Relocation Support: if you're joining us from afar, we'll assist you in making a smooth transition.

We are Rebtel. We come from all around the world to create products for anyone who has crossed a border. We believe in equal opportunity and value diversity at our company. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.