Principal Software Engineer

Invisible Technologies, Inc.; Warszawa; On-site; PLN 472,000 - 611,000; Full time

Job summary

A leading technology firm in Warsaw is seeking a Principal Engineer to support AI Training teams in generating high-quality data. The ideal candidate will have over 10 years of experience in software development, particularly in Python and React, and will oversee data operations while mentoring junior team members. This position offers a competitive salary and a dynamic work environment focused on innovation.

Qualifications

• 10+ years of experience shipping production software.
• Pragmatic approach to software development.
• Ability to lead technical problem solving.

Responsibilities

• Partner with AI Training Delivery teams for data generation.
• Data ingestion into operations management hub.
• Python and Shell scripting for data operations.
• Custom UI development in React.
• Coordinate new feature development.
• Set best practices in software development.
• Lead and mentor junior colleagues.

Skills

Expert competency in Python

Expert competency in React

Command Line competency (Shell / Bash / Zsh)

Knowledge of Data Science and GPU model training

Consulting background from a major consulting firm

Job description

Invisible Technologies makes AI work. Our end-to-end AI platform structures messy data, automates digital workflows, deploys agentic solutions, measures outcomes, and integrates human expertise where it matters most.

Our platform cleans, labels, and structures company data so it is ready for AI. It adapts models to each business and adds human expertise when needed, the same approach we have used to improve models for more than 80% of the world’s top AI companies, including Microsoft, AWS, and Cohere.

Our successes span industries, from supply chain automation for Swiss Gear to AI-enabled naval simulations with SAIC, and validating NBA draft picks for the Charlotte Hornets.

Profitable for more than half a decade, Invisible reached $134M in revenue and ranked as the number two fastest growing AI company on the 2024 Inc. 5000. In September 2025, we raised $100M in growth capital to accelerate our mission of making AI actually work in the enterprise and to advance our platform technology.

About The Role

As a Principal Engineer in our AI Training team you will be serving our high-value foundation model labs accounts using our internal tooling. We expect you to learn the tooling deeply, and understand how to push the bounds of customizing it via scripting, ingestion, and export. You will learn the process our Delivery / Operations team leverages to serve our clients and with your years of experience help us reduce manual work performed between non-technical and technical team members. You will role model great software development delivery in a pragmatic way that is a mix of get-it-done hacker mentality and product oriented agile developer. You know when to choose which style of operations is best for the challenge in front of you. You will help us identify key features that our platform team should provide to codify the learnings the team you work with has handled outside of the platform.

What You’ll Do

• Partner with our AI Training Delivery teams in their effort to generate high quality, curated and audited data for use by AI Researchers at major Foundation Lab model providers.
• Data Ingestion into our NextGen Marketplace Operations Management Hub used to coordinate client-facing campaigns.
• Python and/or Shell Scripting to support transforming, validating, ingesting, and exporting data into and out of Operations Hub.
• Custom UI development in React to embed Annotations tools for orchestrating data capture from our Human Experts for AI Training.
• Coordinate new feature development and solution solve alongside our product core team building NextGen Marketplace, Atomic, Synapse and any other core tools we are enhancing for our AIT Engagements.
• Set best practices in software development from a perspective of fast moving forward deployed engineering motion and pattern recognition to drive product development to reduce customizations for our clients.
• Set a standard of engineering leadership for the more junior colleagues on our team that help them learn from your depth of experience in engineering as it pertains to reproducible delivery.

What We Need

You are an engineer that understands a pragmatic approach to software development as a bright hacker with an awareness of when to slow down and make proper SDLC decisions. You have been shipping production software for 10+ years and welcome a mix of individual contributor ownership as well as leading others on a technical problem solving.

• Expert competency in Python.
• Expert competency in React.
• Command Line competency (Shell / Bash / Zsh).
• Nice to haves.
• Knowledge of Data Science and GPU model training.
• Consulting background from a major consulting firm.

What’s In It For You

Invisible is committed to fair and competitive pay, ensuring that compensation reflects both market conditions and the value each team member brings. Our salary structure accounts for regional differences in cost of living while maintaining internal equity.

For this position, the annual salary range is:

Salary Range

$130,000 - $168,000 USD

You can find more information about our geographic pay tiers here.

For candidates outside the U.S., compensation is adjusted to reflect local market conditions and cost of living.

Bonuses and equity are included in offers above entry level. Final compensation is determined by a combination of factors, including location, job‑related experience, skills, knowledge, internal pay equity, and overall market conditions. Because of this, every offer is unique. Additional details on total compensation and benefits will be discussed during the hiring process.

What It's Like to Work at Invisible:

At Invisible, we’re not just redefining work—we’re reinventing it. We operate at the intersection of advanced AI and human ingenuity, pushing the boundaries of what’s possible to unlock productivity and scale. Ownership is at the core of everything we do. Here, you won’t just execute tasks—you’ll build, innovate, and shape the future alongside world‑class clients pushing the boundaries of AI.

We expect bold ideas, relentless drive, and the ability to turn ambiguity into opportunity. The pace is fast, the challenges are big, and the growth is unmatched. We’re not for everyone, and we’re okay with that. If you’re looking for predictable routines, this isn’t the place for you. But if you’re driven to create, thrive in dynamic environments, and want a front‑row seat to the AI revolution, you’ll fit right in.

Equal Opportunity Statement: We’re an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, national origin, disability, or veteran status, or any other basis protected by law.

Accessibility Statement: We’re committed to providing reasonable accommodations for individuals with disabilities. If you need assistance or accommodation due to a disability, please contact our Talent Acquisition team during the recruitment process at [e-mail].