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Founding Engineer – Recommendation Algorithm

TechTree's client
Salary
€72k – €102k
Work mode
On-site
Sofia, BulgariaOn-site

What we're looking for

  • 4+ years of experience in Machine Learning, Recommendation Systems, or Applied AI
  • Experience building recommendation algorithms in production environments
  • Strong understanding of ML fundamentals and mathematical concepts
  • Experience training and evaluating recommendation models
  • Ability to work independently and take ownership of core product systems
  • Fluent English

About the role

About the company:
Our client is building the future of mobile gaming by combining the endless-scroll experience of TikTok with instantly playable mini-games.
Users can create games using AI, publish them to the platform, and discover an endless stream of user-generated games. By combining generative AI with gaming and social mechanics, they are creating a completely new category of entertainment.
The company is based in Sofia, Bulgaria, and is backed by experienced founders with deep expertise in gaming, AI, and product development.

The team is currently preparing for an important investor demo and is looking for exceptional founding team members who want to help build the company from an early stage.

We are looking for a Founding Engineer focused on Recommendation Systems and Machine Learning. You will own the recommendation engine that powers game discovery, engagement, retention, and personalization across the platform.

Requirements:
4+ years of experience in Machine Learning, Recommendation Systems, or Applied AI
Experience building recommendation algorithms in production environments
Strong understanding of ML fundamentals and mathematical concepts
Experience training and evaluating recommendation models
Ability to work independently and take ownership of core product systems
Fluent English


Skills:
Recommendation systems
Ranking algorithms
Feature engineering and feature extraction
User personalization systems
Two-tower architectures
Neural networks and activation functions
LLMs and prompting systems
Python and ML tooling
Data-driven experimentation and optimization


Nice to Have:
Experience working on social media recommendation systems
Experience building large-scale personalization engines
Startup experience
Experience with consumer-facing products
Experience in gaming, entertainment, or content discovery products


What We Offer:
Salary range: €6,000–€8,500 net/month
Meaningful equity package
Founding team opportunity
Direct impact on product direction and company success
Work with AI-native gaming products
Fast-moving startup environment
Opportunity to relocate to Sofia and work closely with founders


Recruitment Process:
Technical interview with founders
Culture fit interview
Technical presentation / case study discussion
Final decision

Compensation & benefits

Salary: €72k – €102k
Salary range: €6,000–€8,500 net/month
Meaningful equity package
Founding team opportunity
Direct impact on product direction and company success
Work with AI-native gaming products
Fast-moving startup environment
Opportunity to relocate to Sofia and work closely with founders

Equity details

Type: equity package
Details: Meaningful equity package

About TechTree's client

This innovative company is building the future of mobile gaming by combining the endless-scroll experience of popular social media platforms with instantly playable mini-games. Users can create games using AI, publish them to the platform, and discover an endless stream of user-generated games. By combining generative AI with gaming and social mechanics, this organization is creating a completely new category of entertainment. The company is based in Sofia, Bulgaria, and is backed by experienced founders with deep expertise in gaming, AI, and product development.

Ready to apply?

Submit your application today.

Founding Engineer – Recommendation Algorithm
€72k – €102k