Senior Data Engineer - Recommendations

Events by L; Stockholms kommun; On-site; SEK 900,000 - 1,300,000; Full time

Benefits offered by this job

Private health insurance

Pension

Wellness contributions

Office culture and Lab Days

Job summary

Truecaller is seeking a Senior Data Engineer to own the data foundation behind their recommendation and advertising ML systems. You will build feature pipelines, streaming ingestion, and a real-time feature store to power large-scale models and real-time inference.

The role partners with data scientists to bring models from notebook to production, ensuring data contracts, freshness SLAs, and lineage. You will implement scalable pipelines and best practices across the team.

Qualifications

• Strong programming in Python and Spark, with ETL/ELT pipelines.
• Experience with orchestration tool like Airflow in production.
• Experience with large datasets on cloud (GCP preferred; AWS/Azure also fine).

Responsibilities

• Build and own the feature and training-data pipelines for retrieval, ranking, and contextual-bandit models.
• Design streaming pipelines to capture impressions, clicks, conversions in near real time.
• Maintain a real-time feature store for consistent offline/online data.
• Own the ad-event and attribution data backbone for delivery, billing, and partners.
• Collaborate with data scientists to move models from notebook to production, managing data contracts and lineage.
• Create reusable, config-driven frameworks to onboard new models and campaigns.
• Ensure platform reliability at scale with monitoring and data quality checks.

Skills

Python

Spark

ETL/ELT pipelines

CI/CD

Communication

Problem solving

Data science collaboration

Tools

Airflow

Git

Jenkins

BigQuery

Cloud platforms (GCP/AWS/Azure)

Job description

Join Truecaller – The place where innovation meets impact! Truecaller's mission is to build trust in communication by making it safer, smarter, and more efficient. Born in Sweden, trusted by the world, and here's why we stand out:

• We are trusted by over 450 million active users every month across 190+ countries
• We identify over 15 billion calls daily, helping users avoid spam and scams
• We are powered by a team of 450+ employees from 45+ nationalities

We always look for people who take initiative, own their work, and keep raising the bar. An entrepreneurial mindset matters here, especially when it turns bold ideas into real actions. We stay collaborative and focused, always searching for smarter paths forward. If you want to make an impact and grow with a team that inspires millions, you'll fit right in.

The role

As a Senior Data Engineer on our Recommendations and adVantage teams, you will build and own the data foundation behind Truecaller's recommendation and advertising machine‑learning systems. That means the feature pipelines, streaming event ingestion, training datasets, and real‑time feature serving that power the retrieval, ranking, and contextual‑bandit models deciding what hundreds of millions of users see. This is a hands‑on platform role at the point where large‑scale data engineering meets production machine‑learning.

What you’ll do

• Build and own the feature and training‑data pipelines behind our retrieval, ranking, and contextual‑bandit models, taking raw events all the way to model‑ready features.
• Design streaming pipelines that close the loop between serving and learning, capturing impressions, clicks, and conversions in near real time so models retrain on fresh signal.
• Stand up and maintain a real‑time feature store so features stay consistent between offline training and low‑latency online inference.
• Own the ad‑event and attribution data backbone: clean, reconciled pipelines for delivery, billing, and third‑party attribution partners.
• Partner directly with data scientists to move models from notebook to production, owning the data contracts, freshness SLAs, and lineage they depend on.
• Build reusable, config‑driven frameworks so new models and campaigns onboard without bespoke pipeline work each time.
• Keep the platform reliable at scale: billions of events daily within defined SLAs, backed by monitoring, data‑quality checks, and dependable backfills.
• Set best practices and processes around pipeline design, testing, and data modeling across the team.

What you bring in

• Strong programming skills in Python and Spark, with a track record of building complex, large‑scale ETL/ELT pipelines.
• Hands‑on experience with an orchestration tool such as Airflow, feeding ML or analytics workloads in production.
• Experience working with large datasets on a major cloud provider (GCP preferred; AWS or Azure also fine).
• Solid software engineering fundamentals: testing, CI/CD with Git and Jenkins or similar, and code you would be happy to maintain.
• Comfort working shoulder to shoulder with data scientists and ML engineers, and a clear understanding of what production ML needs from data – features, freshness, consistency, and lineage.
• Excellent problem‑solving and communication skills, and the self‑motivation to own problems end to end.

It would be great if you also have

• Experience with streaming systems such as Kafka, Flink, or Spark Structured Streaming.
• Experience with a feature store (Feast, Vertex AI, Tecton, or in‑house).
• Exposure to recommendation, ranking, or ads from ML systems and the data they rely on.
• Knowledge of Kubernetes.
• Experience managing a data warehouse in BigQuery (preferred) or Redshift.

What we offer

We support growth through learning resources, leadership programs, mentoring, and real hands‑on work. People can move between teams and projects to build new skills and keep things interesting. We offer clear internal mobility and a transparent path for progression, with leaders who stay involved and provide guidance throughout the year.

• A comprehensive compensation package: we offer a competitive salary, 30 days of paid vacation, private health insurance, parental leave top‑up, pension, and wellness contributions.
• Modern tools to do your best work: choose your preferred computer and phone within our budget, so you can work comfortably and efficiently.
• A people‑focused office culture: we value in‑person collaboration and follow an office‑first model, with some flexibility. Our offices offer a vibrant environment with opportunities to learn, connect, and recharge, from breakfast, lunch, and well‑stocked snack stations and quiet spaces to team activities such as movie nights, tech meetups, and cultural events. There's something for everyone.
• Truecaller's "Lab Days" offer a space for imagination: 5 times per year for 3 days, where everyone steps away from their normal tasks to explore new, bold ideas and build things they've always wanted to. It's a space where curiosity leads the way, and prototypes take shape. Some concepts even make it into production, and a few have grown into real features used by millions today. Lab Days allow you to be creative, learn fast, and help shape Truecaller's future.

Come as you are

Truecaller is committed to building a diverse and inclusive team. We believe that a wide range of backgrounds, perspectives, and experiences strengthens our products and our culture. No matter where you're from, what language you speak, or how you identify, we value what makes you unique and would love to get to know you.

We only accept applications in English.