Marketing Engineer

fonio.ai; Greater London; On-site; GBP 56,000 - 111,000; Full time

Benefits offered by this job

Relocation bonus

Equipment of your choice

Equity stake

Vienna office lunches/dinners

Job summary

fonio.ai is seeking a Marketing Engineer to bridge data science and paid media. You will build end-to-end ML models that score leads and estimate CLTV, consolidating signals into a single data source and feeding insights back to ad platforms to optimize campaigns.

This hands-on role offers ownership of models and infrastructure, with collaboration across Performance Marketing and GTM teams. Relocation to Vienna is available with benefits and equipment provided.

Qualifications

• Experience building data pipelines and ML models using Python and SQL.
• Understanding paid media signals and how platforms consume them.
• Experience with attribution or offline conversion uploads is a strong plus.
• Strong English skills; German skills are a big plus.

Responsibilities

• Build predictive CLTV modelling from the ground up and consolidate signals into a database.
• Develop ML models to score leads based on user behavior.
• Feed scores back into ad platforms (Meta, Google) to sharpen targeting and bidding.
• Own tracking and conversion infrastructure (Tag Manager, Search Console, offline uploads, server-side setups).
• Turn raw behavioral data into measurable performance impact and collaborate with Growth/Marketing teams.

Skills

Python

SQL

ML tooling

Data pipelines

Tools

Tag Manager

Search Console

offline uploads

Job description

About fonio

We grew from $1M to $10M ARR in under 12 months and now serve 10,000+ customers.

Fonio is Europe’s market leader for AI phone agents for SMBs. Now we’re expanding globally and into new products.
We move fast, take ownership, give direct feedback, and avoid politics and unnecessary meetings.
Join one of Europe’s fastest-growing companies.

Your Role

As our Marketing Engineer, you sit at the intersection of data science and paid media. You'll consolidate scattered customer signals into a single source of truth, build ML models that score leads by their real value, and feed those insights back into our ad platforms - making our marketing smarter than the platforms' out-of-the-box optimization. It's a hands-on, build-from-scratch role with full ownership over both the models and the impact they create.

What to expect

• Build our predictive CLTV modelling from the ground up: consolidate customer signals into a database, develop ML models on user behavior to score leads

• Feed those scores back into the ad platforms (Meta, Google, and more) to sharpen targeting and bidding

• Own tracking and conversion infrastructure: Tag Manager, Search Console, offline uploads, server-side setups

• Turn raw behavioral data into measurable performance impact

• Work closely with the Performance Marketing team and Go-to-Market managers

Who We’re Looking For

• You're comfortable building data pipelines and ML models - Python, SQL, and modern ML tooling are second nature

• You understand paid media well enough to know what signals matter and how platforms consume them

• Experience with attribution, conversion APIs, or offline conversion uploads is a strong plus

• Hardworking, analytical, structured, and a natural fit for a direct, ambitious culture

• Strong English skills, as English is our company language

• German skills are a big plus

What We Offer

• Competitive Salary: €65.000-€130.000

• Equity - you build it, you should own a piece of it.

• Food & drinks - at our Vienna office, lunch and dinner are on us (plus all the drinks your heart desires, and yes, we have protein bars and vitamins too).

• Relocation bonus (if you still need to move to Vienna)

• Equipment of your choice - whatever makes you happy.

• Regular team offsites.

Hiring Process

1. 15 min intro call

2. 30 min skill interview

3. 15 min Culture fit with the founders