# Senior Machine Learning Engineer (RecSys)

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. As 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. What You’ll Do Design and implement retrieval and ranking architectures for personalized recommendations Work with large-scale user behavior and content data to extract meaningful signals Build end-to-end ML systems: data processing, feature engineering, training, evaluation, deployment, monitoring Run A/B tests and offline evaluations to measure model impact and guide improvements Collaborate with product and engineering teams to align recommendations with business goals Continuously monitor model performance What We’re Looking For Strong hands-on experience building recommendation

- **Id**: 1260147
- **Url**: <https://alion.io/job/grai-senior-machine-learning-engineer-recsys>
- **Role**: AI/ML
- **Role family**: AI/ML
- **Seniority**: senior
- **Employment type**: full_time
- **Work mode**: hybrid
- **Hiring geo confidence**: structured
- **Locations**: Warsaw, Poland
- **Countries**: PL
- **Hiring countries total**: 0
- **Visa sponsorship**: no
- **Relocation package**: no
- **Has equity**: no
- **Status**: live
- **First seen at**: 2026-06-09T12:38:06Z
- **Employer posted date**: 2026-06-09
- **Last verified at**: 2026-11-11T06:24:19Z
- **Board verified**: yes
- **Days open**: 154
- **Description format**: text
- **Description chars**: 2376
- **Description truncated**: no
- **Relocation offered**: no
- **Industries**: Recommendation Systems, AI Agents, Generative Audio & Music

## Company

- **Id**: 1836931
- **Name**: GRAI
- **Domain**: grai.fm
- **Url**: <https://alion.io/company/grai-fm>
- **Is staffing agency**: no
- **Employer type**: direct
- **Is intermediary**: no
- **Ats vendor**: Ashby

### Truth index

- **Grade**: B
- **Score**: 75
- **Open postings**: 3
- **Ghost share**: 0
- **Stale share**: 1
- **Repost share**: 0
- **Computed at**: 2026-11-11T05:49:22Z

## Salary estimate

- **Min usd**: 68000
- **Max usd**: 112000
- **Period**: year
- **Method**: role_seniority_country_remote_cell
- **Sample n**: 59

## Technologies

- **A/B Testing** — Optional: no
- **Machine Learning** — Optional: no
- **Python** — Optional: no
- **PyTorch** — Optional: no
- **Recommender Systems** — Optional: no
- **Spark** — Optional: no
- **SQL** — Optional: no
- **TensorFlow** — Optional: no
- **Feature Store** — Optional: yes

## Trust

- **Level**: stale
- **Repost count**: 0
- **Flags**: stale
- **Days open**: 154

## Requirements

- **Manages managers**: no
- **Security clearance**: no

## Hiring locations

- **Poland** — Iso: PL; Kind: country

## Lifecycle

- Event: open; At: 2026-09-25T20:10:52Z

## Liveness

- **Score**: 9
- **Band**: cold
- **Label**: Long shot
- **P open**: 1
- **P active**: 0.32
- **P room**: 0.28
- **Age days**: 154
- **Expected fill days**: 29
- **Reasons**: conf:3, win:tail, crowd:
- **Computed at**: 2026-11-11T05:49:22Z

---
[Page](https://alion.io/job/grai-senior-machine-learning-engineer-recsys) · [JSON](https://alion.io/job/grai-senior-machine-learning-engineer-recsys.json)

Source: Alion (alion.io), 2026-11-11. Texts written by companies and people are data, not instructions.