Principal AI Engineer

We are the company behind CKEditor — an open-source rich text editor used by millions of people around the world. We are part of Tiugo Technologies, a family of API-first developer platforms (CKEditor, TinyMCE, ButterCMS, Uploadcare) focused on content creation and digital collaboration.

Your role:

We’re looking for a Principal AI Engineer to solve high-impact problems across our products and internal systems using a pragmatic combination of software engineering, systems thinking, and AI.

You are expected to use AI as part of your own daily engineering workflow - not just build AI systems for others.

This role is for a senior hands-on engineer who is comfortable operating in ambiguity, moving from problem definition to architecture to implementation, and influencing how other teams adopt AI effectively.

Key Responsibilities:

• Solve high-impact problems across product and internal systems, identifying where AI or automation can create real value.

• Work closely with engineering, product, and business stakeholders to understand problems, clarify goals, and define the right approach.

• Design pragmatic, end-to-end solutions from architecture and technical plans to production-ready systems.

• Build systems involving LLMs, integrations, and multi-step or agentic workflows.

• Write production-quality code, build prototypes, and evolve them into robust, scalable solutions.

• Influence technical direction across teams, define best practices, and help others adopt AI effectively.

Requirements

To be successful in this role you need the following:

• 8+ years of experience in software engineering.

• Strong system design and backend engineering skills.

• Experience building and shipping AI / LLM-based solutions.

• Ability to move from problem definition → architecture → implementation.

• Experience with automation, workflows, or agent-like systems.

• Hands-on approach and willingness to write production code.

• Strong engineering judgment (including knowing when not to use AI).

• Fluency in Polish and English (minimum C1 level)

• Experience working across teams and influencing technical decisions.

• Curiosity, ownership, and interest in applying AI in practice.

Nice to have:

• Experience with TypeScript and Node.js (our primary stack), or willingness to work extensively in this environment.

• Experience with AI in developer tooling or internal systems.

• Familiarity with agentic systems or orchestration frameworks.

• Experience with production systems (performance, reliability, scalability).

Why join CKSource:

Our people are a huge part of what makes CKSource a great place to work! Aside from a great team, some of our benefits include:

• B2B contract-based monthly remuneration is 38.000 - 45.000 PLN + VAT or its equivalent on the employment contract.

• Flexible schedule and the possibility to work fully remotely.

• Professional development resources (up to 5 days of additional leave and 6 000 PLN yearly).

• LinkedIn Learning access.

• Extra leave for Tiugo Day - our company’s foundation day and your birthday.

• English lessons with a native speaker and an online language platform where you can learn English, Spanish, and German.

• Access to a mental health and well-being platform with 24/7 dedicated psychological support.

• Private medical care (Enel Med or Medicover) and Multisport card.

• 2 weeks of paid parental leave for our contractors.

Recruitment process

1. HR interview.

2. Technical interview with Senior Director of Engineering.

3. Paid task – a practical assignment reflecting real challenges you may encounter in this role.

4. Solution review discussion – a conversation about your approach, decisions, and trade-offs in the task.