{"id":1260147,"url":"https://alion.io/job/grai-senior-machine-learning-engineer-recsys","title":"Senior Machine Learning Engineer (RecSys)","company":{"id":1836931,"name":"GRAI","domain":"grai.fm","url":"https://alion.io/company/grai-fm","size_band":null,"is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Ashby","truth_index":{"grade":"B","score":75,"open_postings":3,"ghost_share":0,"stale_share":1,"repost_share":0,"time_to_fill_p50_days":null,"computed_at":"2026-10-03T05:45:00Z"}},"role":"AI/ML","role_family":"AI/ML","seniority":"senior","employment_type":"full_time","work_mode":"hybrid","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["Warsaw, Poland"],"countries":["PL"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":{"min_usd":68000,"max_usd":117000,"period":"year","method":"role_seniority_country_remote_cell","sample_n":38},"experience_years_min":null,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"A/B Testing","optional":false},{"name":"Edge AI","optional":false},{"name":"Machine Learning","optional":false},{"name":"Python","optional":false},{"name":"PyTorch","optional":false},{"name":"Recommender Systems","optional":false},{"name":"Spark","optional":false},{"name":"SQL","optional":false},{"name":"TensorFlow","optional":false},{"name":"Feature Store","optional":true}],"status":"live","first_seen_at":"2026-06-09T12:38:06Z","employer_posted_date":"2026-06-09","last_verified_at":"2026-10-04T00:27:16Z","board_verified":true,"closed_at":null,"days_open":116,"trust":{"level":"stale","repost_count":0,"flags":["stale"],"days_open":115},"description":"We are building an AI-powered music platform that’s transforming how people create, explore, and experience music. Our product leverages cutting-edge AI technologies to provide personalized music recommendations and unique features tailored to every music enthusiast.\nAs we continue to grow, we’re looking for aSenior Machine Learning Engineer to design, build, and scale recommendation systems that deliver highly relevant, personalized experiences to our users. You will work on large-scale user interaction data, develop retrieval and ranking models, and take them from experimentation to production.\nWhat You’ll Do\nDesign and implement retrieval and ranking architectures for personalized recommendations\n\nWork with large-scale user behavior and content data to extract meaningful signals\n\nBuild end-to-end ML systems: data processing, feature engineering, training, evaluation, deployment, monitoring\n\nRun A/B tests and offline evaluations to measure model impact and guide improvements\n\nCollaborate with product and engineering teams to align recommendations with business goals\n\nContinuously monitor model performance\n\nWhat We’re Looking For\nStrong hands-on experience building recommendation systems or ranking models\n\nDeep understanding of machine learning fundamentals and evaluation methodologies\n\nExperience working with large-scale data (SQL, Spark, or distributed data systems)\n\nProficiency in Python and modern ML frameworks (PyTorch, TensorFlow)\n\nUnderstanding of core ML concepts: supervised/unsupervised learning, evaluation metrics, feature engineering\n\nExperience deploying ML models to production and maintaining them over time\n\nAbility to balance experimentation with production reliability\n\nNice to Have\nExperience with real-time recommendation systems\n\nKnowledge of search / information retrieval systems\n\nFamiliarity with feature stores, model monitoring, and ML infrastructure\n\nExperience in media, music, or consumer-facing personalization products\n\nWhy Join Us\nWork on high-impact ML systems used by real users at scale\n\nOwnership over meaningful technical decisions, from modeling to production\n\nCollaborative, product-driven environment with strong engineering culture\n\nA supportive and dynamic startup culture where your ideas and contributions truly matter\n\nOpportunities for growth, learning, and shaping the future of our recommendation stack","description_format":"text","description_chars":2376,"description_truncated":false,"requirements":{"experience_years_min":null,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[]},"benefits":[],"hiring_locations":[{"name":"Poland","iso":"PL","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Generative Audio & Music"],"lifecycle":[{"event":"open","at":"2026-09-25T20:10:52Z"}],"visa":[],"liveness":{"score":10,"band":"cold","label":"Long shot","p_open":1,"p_active":0.344,"p_room":0.28,"age_days":115,"expected_fill_days":25,"reasons":["conf:23","win:tail","crowd:"],"computed_at":"2026-10-03T05:45:00Z"},"pay":null,"html_url":"https://alion.io/job/grai-senior-machine-learning-engineer-recsys","json_url":"https://alion.io/job/grai-senior-machine-learning-engineer-recsys.json","meta":{"generated_at":"2026-10-04T00:28:20Z","cache_seconds":300,"methodology":"https://alion.io/methodology","terms":"https://alion.io/terms","contact":"https://alion.io/contact","api":"https://alion.io/developers","usage":{"tier":"crawler","counted_by":"address","units_charged":1,"used_today":529,"day_limit":5000,"remaining_today":4471,"minute_limit":60,"resets_at":"2026-10-05T00:00:00Z"}}}