Senior ML Engineer - Email Security (Remote, Flexible)

CloudLinux Inc.; Województwo mazowieckie; Remote; PLN 180,000 - 320,000; Full time

Benefits offered by this job

Fully remote

Paid vacation

National holidays

Unlimited sick leave

Private medical insurance

Co-working stipend

Education budget

Patent incentive

Job summary

CloudLinux is a globally remote-first company building Imunify security products. We are replacing our rspamd-based spam filter with a transformer model running on customer CPUs, and we are seeking a Senior Machine Learning Engineer to drive development and production rollout of our email security tech.

You will ship detection models, build the Go-based inference engine, and own model quality end-to-end while collaborating with engineers.

Qualifications

• 5+ years shipping detection or classification systems where false positives have a cost you defended.
• You have taken at least one ML classifier to production yourself: corpus construction, threshold selection, error analysis.
• Hands-on transformer training in PyTorch: tokenizers, masked-language pre-training, fine-tuning, ONNX export, CPU inference measurement.
• Linux, shell, and Python on shared servers and a shared GPU.
• Daily usage of AI coding agents and tools.
• English at upper-Intermediate (B2) level or higher with strong written communication for docs, specs, and code reviews.

Responsibilities

• Train, evaluate, and release spam-detection models: build corpus, set thresholds, review precision/recall.
• Build the production side of the new engine in Go: inference service, mail-filter integration, tokenizer, streaming parser.

Skills

Detection systems

Production ML

PyTorch

Go/Rust

Python

Linux

Shell

ONNX

English (B2+)

Tools

Go

Rust

TensorFlow/ONNX

Job description

CloudLinux is a globally remote-first company building Imunify security products. We are replacing our rspamd-based spam filter with a transformer model running on customer CPUs, and we are seeking a Senior Machine Learning Engineer to drive development and production rollout of our email security tech.

You will ship detection models, build the Go-based inference engine, and own model quality end-to-end while collaborating with engineers.