Company

Technology

SeniorMachineLearningEngineer,Recommendation

€75–110k ~AI est. Bulgaria FULL TIME Remote Friendly
Market Sentiment
HIGH DEMAND

Neural analysis suggests this role is
optimal for Senior candidates.

The Brief

“Senior Machine Learning Engineer, Recommendation. Skills: Recommendation systems, Machine Learning, Ranking models, Retrieval techniques. Design recommendation systems. Improve recommendation systems”

What You'll Achieve.

Measurable improvements in engagement; Measurable improvements in retention; Measurable improvements in satisfaction; Measurable improvements in content distribution; Enhance product performance; Enhance user experiences

Industry & Context.

Technology
Problems you'll solve

Problem-solving ability

What They're Looking For.

Must Have

5+ years industry experience, Experience building production ML systems, Experience developing recommendation engines, Experience with retrieval and ranking architectures, Understanding of evaluation methodologies, Solid engineering fundamentals, Communication and collaboration skills

Nice to Have

Experience with semantic search, Experience with AI-powered recommendation systems, Experience with LLM-enhanced ranking, Experience with personalized content generation, Experience with multimodal machine learning, Familiarity with reinforcement learning, Familiarity with contextual bandits, Familiarity with explore/exploit strategies, Familiarity with long-term optimization frameworks, Familiarity with user-generated content ecosystems, Startup experience, Experience building ML systems from scratch

What You'll Do.

Design recommendation systems

Improve recommendation systems

Develop retrieval systems

Optimize ranking systems

Develop candidate generation pipelines

Develop embedding-based retrieval

Develop two-tower architectures

Develop ranking models

Develop serving infrastructure

Lead experimentation efforts

Improve models iteratively

Improve recommendation quality

Address cold-start users

Address creator discovery

Address evolving content ecosystems

Build user representations

Build creator representations

Build content representations

Build session representations

Use behavioral signals

Use contextual signals

Use engagement signals

Collaborate with Product teams

Collaborate with Data Science teams

Collaborate with Engineering teams

Define success metrics

Deliver measurable improvements

Develop production ML systems

Implement robust monitoring

Implement evaluation standards

Implement scalability standards

Implement reliability standards

Contribute to ML infrastructure evolution

Contribute to ML architecture evolution

Support AI-native discovery experiences

Translate user behavior patterns

Translate complex datasets

Enhance product performance

Enhance user experiences

Stay current with advancements

Research recommendation systems

Research ranking methodologies

Research retrieval techniques

Research AI personalization

How You'll Work.

Team & Collaboration

Product teams; Data Science teams; Engineering teams

Full Job Description

## Accountabilities Design, build, and continuously improve recommendation and search systems across content feeds, discovery experiences, search functionality, and content continuation features. Develop and optimize retrieval and ranking systems, including candidate generation pipelines, embedding-based retrieval, two-tower architectures, ranking models, and serving infrastructure. Lead end-to-end experimentation efforts, including hypothesis development, A/B testing, performance analysis, and iterative model improvements. Improve recommendation quality across key challenges such as cold-start users, newly created content, creator discovery, and rapidly evolving content ecosystems. Build user, creator, content, and session-level representations using behavioral, contextual, and engagement signals. Collaborate closely with Product, Data Science, and Engineering teams to define success metrics and deliver measurable improvements in engagement, retention, satisfaction, and content distribution. Develop production-grade machine learning systems with robust monitoring, evaluation, scalability, and reliability standards. Contribute to the evolution of long-term machine learning infrastructure and architecture supporting AI-native content discovery experiences. Translate user behavior patterns and complex datasets into actionable machine learning solutions that enhance product performance and user experiences. Stay current with emerging advancements in recommendation systems, ranking methodologies, retrieval techniques, and AI-powered personalization technologies. Requirements 5+ years of industry experience building and deploying production machine learning systems with significant ownership and technical leadership responsibilities. Proven experience developing recommendation engines, search systems, ranking models, feed optimization systems, advertising ranking platforms, or content discovery solutions. Strong background working on consumer-facing applications, particu

Free ATS check

Applying for this Senior Machine Learning Engineer, Recommendation role?

Most applicants get filtered before a human reads their resume. See if yours makes the cut.

How to Apply on Lever

  • Lever uses a streamlined one-page form — apply in under 5 minutes.
  • LinkedIn import works well; review parsed data before submitting.
  • The cover letter field is optional but visible to reviewers — use it to differentiate.
  • Referral codes from employees can significantly boost visibility of your application.

ANONYMOUS · UNFILTERED

What do employees actually say about this company?

Real rants from real employees. Read before you apply.

Read Company Rants →