Principal AI Engineer- I

WHO WE ARE

Deutsche Telekom Digital Labs is the engineering hub of Deutsche Telekom, Europes #1 telecom brand. We build the digital products that millions of customers across Europe use every day. AI-first by design, we dont just adopt new technology, we build with it.

You will be part of Deutsche Telekom:

• #1 most valuable telecom brand in the world, and #11 across all brands (Brand Finance Global 500, 2026)
• Top 100 in the Fortune Global 500 (#72 in 2025)
• EUR 119 billion Group revenue in 2025
• 273 million+ mobile customers in 50+ countries

ABOUT THE TEAM

With the right team, anything is possible. This is where AI stops being a feature and becomes the product. OneAI builds the intelligence layer that powers customer-facing AI experiences across Deutsche Telekom, from conversational assistants to recommendation engines that actually understand context. If you want to work on AI that millions of people interact with every day, not in a lab, not in a demo, but in the real world at real scale, this is your team. We dont just deploy models. We build the systems that make them trustworthy, useful, and impossible to ignore.

YOU ASK WHATS IN IT FOR YOU WE SAY,

• AI tools, on us — Every engineer ships with AI. Coding agents, token budgets and hackfests to build whats next.
• Grow faster — Free Coursera & Udemy access, certifications and internal mobility across teams.
• Time to recharge — Uncapped leaves, birthday leave, flexible hours, and sabbatical options.
• Family first — 9 months maternity on full pay, 15 days paternity, crèche support, infertility treatment and adoption leave.
• Health & wellness — Medical cover up to 15L for you and your family, unlimited free doctor consults, 24/7 counselling and free Cult.fit membership.
• Money & everyday — Flexi benefits for car, fuel and books. Free meals and snacks on campus. Monthly phone and broadband allowance, plus relocation support when you need it.

What exactly is the objective of this role

Production / apps focus:

• Design and ship AI-powered product features (LLMs, RAG, agents, ML APIs) into our existing services, working closely with backend, frontend, and data science teams.
• Integrate off-the-shelf and inhouse models (LLMs, embeddings, ML APIs) into robust microservices and user facing flows.
• Design and implement RAG and workflow/agent pipelines: retrieval, context assembly, tools integration, guardrails, and fallbacks.
• Own AI service reliability in production: latency, throughput, cost, observability, circuitbreakers, and rollback/versioning of models and prompts.
• Collaborate with Data Scientists who own model training/finetuning and evaluation design; productionize their outputs as stable APIs/workflows.
• Implement logging, feedback capture, and lightweight online evaluation hooks to measure quality of AI features over time.
• Ensure safety, security, and compliance for AI features: prompt injection defenses, PII handling, abuse/hallucination controls, and audit trail.
• Contribute to internal AI tooling: SDKs, templates, and reusable components to accelerate future AI use case.

Delivery ownership:

• AI Engineer role demands more than AI-based augmentation with in-depth understanding of concepts like-
• RAG
• GenAI, LLM finetuning, Prompt engineering
• Multi-Agent framework (langchain, langraph etc with hands on experience)
• Eval generation and their importance
• Tokens usage and optimisations.
• Model/mcp gateway

MUST HAVE

• Strong software engineering in Python (and one of Node/Java/Go), REST/gRPC APIs, queues, and microservices on cloud infra.
• Handson experience shipping at least one AI powered product to production (e.g., search, recommendations, chatbots, summarization, classification)
• Practical knowledge of LLM concepts: prompts, context engineering, embeddings, vector search, basic evaluation metrics, and latency/cost trade-offs.
• Solid understanding of integration patterns with third party AI providers (OpenAI, Anthropic, etc.) and vector DB
• Hand-on & good understanding of atleast one agentic framework like Langgraph.

WITH THE RIGHT TEAM, ANYTHING IS POSSIBLE.

• If youre looking for an environment thats fun and friendly but incredibly fast-paced; a place where we measure the time between releases in days; a place where our focus begins and ends at the consumer, wed love to have you!

JOIN US!