ST

SENIOR AI ENGINEER, SEARCH

Stealth

Stockholm, SEonsitePosted Aug 26, 2026
Posting intelligenceActively listed

Skills

classificationexpressgithubnaturallanguageprocessing

About the role

Who We Are

We are a well-funded, early-stage technology company on a mission to fundamentally redefine the way the world searches, discovers, and transacts, built on a philosophy that puts the user first at every step.

The user is not simply a means of transaction. They are a valued participant whose data works for them, not against them, enriching their world and their own experience within it, with them retaining full control.

Our mission is underpinned by proprietary, patent-pending technology built on a novel engine and system.

The Problem You Will Be Solving

The internet was built to inform the many, not to serve the individual. Platforms optimize for engagement, extraction, and consumption at global scale. AI has made this model even more efficient, with the user still largely remaining the input, not the full beneficiary.

The problem is not information. The world has never had more. The problem is that people give away a lifetime of data without receiving the personalized experience it should enable.

People should not have to search. They should simply find.

Who You Are

Highly talented and motivated to build products with people, for people

You thrive in zero-to-one environments and find genuine satisfaction in creating from scratch

A fast-paced thinker with a relentless desire to learn, improve, and raise the standard around you

Able to inspire, elevate, and collaborate; you make the people around you better

A great communicator; you express complex ideas with clarity, precision, and confidence across all levels of the organization

Able to transform ideas into working systems and technical milestones with light speed and precision

Highly ambitious and action-driven; you thrive under pressure and find genuine energy in working at the edge of what is considered possible

Capable of designing and building production-grade systems in a fourth of the time most experienced and “sane” professionals would consider possible

What You Will Do

Build query understanding pipelines covering intent classification, named entity recognition, semantic parsing, and contextual query expansion across diverse and multilingual query distributions

Design and build dense retrieval infrastructure including bi-encoder and cross-encoder architectures that retrieve and rank results based on deep semantic understanding of user intent

Build re-ranking systems that refine candidate result sets to surface the most accurate and contextually relevant results at query time

Design and operate RAG pipelines that assemble accurate, contextually appropriate information from multiple retrieval sources and deliver it through a generative interface grounded in current data

Fine-tune pretrained language models on domain-specific data to enhance vocabulary coverage, entity understanding, and query pattern recognition where general-purpose models fall short

Build precision evaluation infrastructure including query-level relevance assessment, coverage analysis, and longitudinal quality tracking across the full distribution of real user queries

Minimum Qualifications

MSc in Natural Language Processing, Information Retrieval, Computational Linguistics, or Computer Science from KTH, Stockholm University, Chalmers, ETH Zurich, or an institution of equivalent standing

Production experience building semantic search or information retrieval systems that real users depend on

Architectural understanding of transformer models; not surface-level API familiarity but genuine comprehension of model behavior from first principles

Proficiency across the Hugging Face ecosystem; fine-tuning methodology, evaluation, and efficient production deployment

Preferred Qualifications

PhD in NLP, Information Retrieval, or a directly related field; given significant weight in our assessment

Research publications in information retrieval, NLP, or related areas

Experience designing retrieval systems that account for rich contextual signals beyond the query alone

Multilingual NLP experience across European languages

2–6 years of industry or research experience

What We Offer

Expect the most talented, rigorous, and driven colleagues you have worked with; people who lift each other up and hold each other to the highest standard. This company is driven by ideas and innovation, regardless of age, position, or background. The best ideas must win and the people behind them recognized and rewarded.

A home for exceptional people and geniuses within their domain; those who have always known what they are capable of and have been waiting for the environment to prove it to the world, whilst first being seen and supported by their coworkers.

Compensation includes an attractive salary and meaningful equity ownership for an early-stage startup.

Equal Opportunity

Application

To apply, send your CV/resume with direct references, GitHub profile, LinkedIn profile, and a brief note on how and why you would like to contribute to our mission. Upon initial acceptance, an in-person interview will follow shortly in Stockholm, Sweden.

Please note that all applications and interviews are conducted in English. Fluency in written and spoken English is a requirement for all roles.

All applications are treated with strict confidentiality.

Questions about this role

Click "Apply with AI Applyd" above and you are done. Your resume is rewritten for this advert, the screening questions are answered, and it is submitted on Stealth's own hiring system. No retyping your history, no fourteen tabs, no evening lost.

Compensation for Machine Learning Engineer roles in Sweden varies widely by seniority, employer size, and remote vs onsite arrangement. Check the salary range on this listing when published, or browse our Machine Learning Engineer hub for Sweden medians across recent openings.

You never touch the form - the application is filled and submitted for you on Stealth's own hiring system. It is not marked sent when we press submit. It is marked sent when a confirmation from their system arrives at the address we apply with, and your dashboard shows which stage each application is at until then.

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