Applied AI Engineer

BJAK; Warszawa; On-site; PLN 180,000 - 240,000; Full time

Job summary

A1 is seeking an Applied AI Engineer to turn model capabilities into real product behavior. You will own problems end‑to‑end—from shaping model behavior to building systems around it, ensuring reliable production usage.

This role sits at the intersection of ML, systems, and product, focusing on making AI genuinely useful for real users, not just demos.

Qualifications

• Strong foundation in machine learning and modern neural network architectures.
• Hands‑on experience with training, fine‑tuning, or deploying ML models.
• Ability to write clean, production‑quality code.
• Comfort working across abstraction layers (model → infra → product).
• Strong problem‑solving skills in ambiguous, fast‑moving environments.
• Bias toward shipping, iteration, and continuous improvement.

Responsibilities

• Build and ship AI features end‑to‑end (model → system → user experience).
• Design prompts, tools, memory, and agent workflows; iterate on them.
• Turn raw model outputs into structured, reliable, and predictable behaviors.
• Debug issues across the full stack (model, orchestration, infra, UX).
• Optimize for latency, cost, and production reliability.
• Develop lightweight evaluation frameworks to measure real‑world performance.
• Collaborate with product and engineering to translate ambiguous problems into working systems.

Skills

ML foundations

Deploy ML models

Production code

Cross-layer collaboration

Problem solving

Shipping mindset

Tools

Python

PyTorch / JAX

LLMs APIs

Inference / Serving

Vector DB

Job description

About A1

There are over 5 billion users using basic applications today such as 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, organizing 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 an Applied AI Engineer, you will turn model capabilities into real product behavior. You will own problems end‑to‑end, from shaping model behavior, to building the systems around it, to ensuring it performs reliably in production. This role sits at the intersection of machine learning, systems, and product, focusing on making AI actually work for users, not just in demos, but in real‑world usage.

Focus

• Build and ship AI features end‑to‑end (model → system → user experience)
• Design and iterate on prompts, tools, memory, and agent workflows
• Turn raw model outputs into structured, reliable, and predictable behaviors
• Debug issues across the full stack (model, orchestration, infra, UX)
• Optimize for latency, cost, and production reliability
• Develop lightweight evaluation frameworks to measure real‑world performance
• Work closely with product and engineering to translate ambiguous problems into working systems

Tech Stack

• Python
• PyTorch / JAX
• LLMs (OpenAI‑style APIs, LLaMA, Qwen, etc.)
• Inference / serving (e.g. vLLM)
• Vector DB

Ideal Experience

• Strong foundation in machine learning and modern neural network architectures.
• Hands‑on experience with training, fine‑tuning, or deploying ML models.
• Ability to write clean, production‑quality code.
• Comfort working across abstraction layers (model → infra → product).
• Strong problem‑solving skills in ambiguous, fast‑moving environments.
• Bias toward shipping, iteration, and continuous improvement.

Outcomes

• ML models in production meet expected accuracy, latency, and reliability targets.
• Production issues are identified quickly, debugged effectively, and root causes addressed.
• Data pipelines, training loops, and inference systems are robust, reproducible, and maintainable.
• Collaborates effectively with engineers, product, and research teams to deliver reliable ML‑powered features.
• Iterations on models and systems are driven by real‑world signals and measurable improvements.

How We Work

The best products today in the world were built by small, world‑class teams. We make decisions collectively, move at rapid speed, striking a balance between shipping high quality work and learning. Joining our team requires the ability to bring structure, exercise judgment, and execute independently. Our goal is to put in hands of our users a truly magical AI product.

Interview Process

If there appears to be a fit, we'll reach to schedule 3, but no more than 4 interviews. Applications are evaluated by our technical team members. Interviews will be conducted via virtual meetings and/or onsite. We value transparency and efficiency, so expect a prompt decision. If you've demonstrated the exceptional skills and mindset we’re looking for, we’ll extend an offer to join us. This isn’t just a job offer; it’s an invitation to be part of a team that’s bringing AI to have practical benefits to billions globally.