About A1
There are over 5 billion users using basic applications today such email, notes, tasks that are not AI-native. Our mission is to build a proactive smart assistant for everyday users to bring intelligence to conversations, errands, organising and workflows, with minimal prompting.
Our product focuses on achieving high reliability for long-running workflows, persistent context, and real-world task completion. The system must handle multi-step reasoning, interact with external tools, and remain reliable despite non-deterministic model behavior. Our objective is to help users complete tasks daily enjoyable with over ~90%* reduced time.
Role
As a Member of Technical Staff, Machine Learning, you will build core ML components. You will work on real production systems from day one, learning how large-scale ML behaves outside of research settings.
This role is for engineers who want to develop strong systems judgment by shipping, debugging, and iterating on real-world ML.
Focus

Build and improve ML components across data, training, evaluation, and inference.




Fine-tune and adapt models as part of larger production systems.
Implement evaluation and testing to understand model behavior.
Help build and maintain data pipelines for real-world and synthetic data.
Debug model issues, performance problems, and production incidents.
Ship improvements iteratively and learn from real user feedback.
Work closely with senior ML engineers and product teams.
Work under real production constraints: latency, cost, reliability, and safety

Tech Stack

Python
PyTorch / JAX
Production ML systems running on GPUs

Adecuado Experience

Strong foundations in machine learning and modern neural architectures.
Some hands‑on experience training, fine‑tuning, or deploying ML models.
Comfortable writing production-quality code and learning new tools quickly.
Curious, coachable, and eager to learn from real systems in production.
Able to work through ambiguity with guidance and grow ownership over t

📌 Member of Technical Staff, Machine Learning (España)
🏢 Bjak
📍 España