Machine Learning Platform Engineer

ActAI; Warszawa; On-site; PLN 220,000 - 320,000; Full time

Job summary

ActAI in Warsaw is hiring an ML Platform Engineer to build the infrastructure powering our AI capabilities. You will design and operate the systems behind the AI stack, from model training and evaluation to deployment, inference, observability, and continuous improvement.

You will collaborate with AI engineers, researchers, and product teams to turn evolving model requirements into production-ready infrastructure.

Qualifications

• Experience building production ML infrastructure.
• Experience with model deployment, inference, and data pipelines.
• Strong understanding of distributed systems and reliability.
• Ability to write clean, production-quality code.

Responsibilities

• Build ML infrastructure and platforms powering ActAI's AI products.
• Design systems for model training, evaluation, deployment, inference, and experimentation.
• Build and optimise model serving and inference infrastructure for high-throughput and low-latency workloads.
• Improve reliability, scalability, latency, and cost efficiency of AI systems.
• Develop reliable pipelines for data preparation, training, evaluation, model release, and continuous improvement.
• Build platforms and tooling that enable AI engineers and researchers to experiment, evaluate, and ship models faster.
• Develop evaluation and benchmarking infrastructure to measure model quality, performance, and regressions.
• Build production observability, monitoring, tracing, and alerting for AI/ML workloads.

Skills

Python

PyTorch

JAX

LLM serving

TensorRT-LLM

Cloud infrastructure

Distributed systems

ML pipelines

GPU tooling

Vector databases

Tools

vLLM

SGLang

TensorRT-LLM

Job description

There are over 5 billion users using basic applications today such email, notes, tasks, calendar and they're not AI-native. Our mission is to build proactive applications for anyone in the world, who are not used to complex prompting. We aim to bring intelligence to conversations, errands, organising and workflows, with minimal to no prompting.

Our product focuses on achieving high reliability for long-running workflows, persistent context, and real-world task completion. We believe products will greatly reduce hallucinations.

Our objective is to organise anyone's life, allowing us all to spend time on valuable and meaningful things.

About the Role

As an ML Platform Engineer, you will build the infrastructure and systems that power ActAI's AI capabilities.

You will design and operate the systems behind the AI stack, from model training and evaluation to deployment, inference, observability, and continuous improvement.

You will work closely with AI engineers, researchers, and product engineers to turn models into reliable, scalable, and cost-efficient production systems. You will build the platforms, tooling, and infrastructure that enable the team to experiment quickly and bring AI capabilities to production with confidence.

Focus

• Build and operate the ML infrastructure and platforms powering A1's AI products
• Design systems for model training, evaluation, deployment, inference, and experimentation
• Build and optimise model serving and inference infrastructure for high-throughput and low-latency workloads
• Improve reliability, scalability, latency, and cost efficiency of AI systems
• Develop reliable pipelines for data preparation, training, evaluation, model release, and continuous improvement
• Build platforms and tooling that enable AI engineers and researchers to experiment, evaluate, and ship models faster
• Develop evaluation and benchmarking infrastructure to measure model quality, performance, and regressions
• Build production observability, monitoring, tracing, and alerting for AI/ML workloads
• Improve AI systems across reliability, scalability, latency, throughput, and cost
• Identify bottlenecks across the ML stack and continuously improve system performance
• Work closely with AI engineers, researchers, and product teams to turn evolving model requirements into production-ready infrastructure
• Python
• PyTorch / JAX
• LLM and ML serving infrastructure such as vLLM, SGLang, or TensorRT-LLM
• Cloud infrastructure
• Distributed systems
• ML/data pipelines and workflow orchestration
• GPU infrastructure and performance tooling
• Vector databases and retrieval infrastructure

Ideal Experience

• Strong software engineering fundamentals and experience building production systems
• Experience building ML infrastructure, platforms, or production machine learning systems
• Experience with model deployment, inference, evaluation, or data pipelines
• Strong understanding of distributed systems and system reliability
• Ability to write clean, maintainable, production-quality code
• Comfortable working in ambiguous, fast-moving environments
• Bias toward ownership, experimentation, and continuous improvement

Outcomes

• AI infrastructure reliably supports production workloads at scale
• Models can be trained, evaluated, deployed, and improved efficiently
• Inference systems deliver strong latency, throughput, reliability, and cost efficiency
• ML pipelines are reproducible, observable, maintainable, and robust
• Model and infrastructure regressions are detected quickly and diagnosed efficiently
• Common ML infrastructure capabilities become reusable platform primitives rather than being rebuilt for every AI product
• The AI stack can evolve rapidly as new models, architectures, and inference techniques emerge