Senior Prompt Engineer

We are seeking an expert Senior Prompt Engineer to design, optimize, and operationalize the LLM architectures powering BOLD’s consumer-facing career tools. In this role, you will bridge the gap between advanced natural language processing and exceptional user experiences, ensuring our generative AI outputs are safe, hyper-personalized, contextually accurate, and highly reliable.

You are a technical specialist who understands model behavioral nuances, token optimization, latency trade-offs, and system-level prompt chaining. You thrive in an environment balancing rapid prototyping with rigorous, data-driven engineering.

ABOUT THIS TEAM

As a Senior Prompt Engineer, you will sit at the intersection of technical prompt design, rapid prototyping, and rigorous, data-driven evaluation. You will work closely with LLM/Machine Learning Engineers, Product Managers, and UX Designers, acting as the technical specialist who translates product requirements into safe, reliable, production-ready prompt systems.

WHAT YOU’LL DO

• Design, prototype, and iterate complex system prompts, few-shot exemplars, and chain-of-thought structures for consumer AI experiences, including Resume Adaptation, Personalization, and Real-time Feedback.
• Partner with LLM/Machine Learning Engineers, Product Managers, and UX Designers to translate product requirements into technical prompt specifications, optimizing for latency and API costs.
• Architect evaluation frameworks - automated, heuristic, and human-in-the-loop - to benchmark, test, and guardrail LLM outputs against hallucination, bias, and tone drift.
• Develop standardized prompt frameworks, version-control workflows, and operational playbooks to help distributed product teams leverage AI safely and efficiently.
• Monitor the evolving GenAI landscape - OSS models, new architectures, and prompt techniques - to continuously improve product performance and model throughput.

WHAT YOU’LL NEED

• 5+ years of professional experience working closely with language technologies, computational linguistics, or software product development.
• 2+ years of hands-on experience shipping LLM-backed features to production for consumer applications, spanning the full prompt development lifecycle and automated evaluation (eval) prompts.
• Mastery of advanced prompt engineering techniques: few-shot, chain-of-thought, ReAct, and prompt chaining.
• Deep familiarity with LLM evaluation tools and frameworks such as RAGAS, LangSmith, TruLens, or custom heuristic testing.
• Proven ability to manage complex prompt deployment pipelines in a fast-paced, continuous integration environment.
• Fluent English (C1): Strong written and verbal communication skills are a must, as you will work in a global environment.
• Collaborating with global teams, requiring periodic availability in the late afternoon (up to 7:00 PM Polish time).

WHAT’S GOOD TO HAVE

• Experience with resume builder products, HR tech, or career content platforms.
• Familiarity with fine-tuning, RLHF, or preference data collection workflows.
• Experience with structured output validation (JSON Schema, Pydantic, or equivalent).
• Familiarity with orchestration tooling: LangChain, LlamaIndex, LangSmith, PromptLayer, or equivalents.
• Contributions to open-source prompt design projects or published writing on the topic.

HERE’S A FEW OF OUR PERKS & BENEFITS

• Salary range: 16 000 - 18 000 PLN gross (Employment agreement / Umowa o Pracę)
• Private healthcare (Medicover, medical-only or medical with dental care individual package, 100% paid by BOLD).
• Mental health support and resources.
• Multisport Plus card (individual package, 100% paid by BOLD).
• Udemy Business access.
• 100% remote work (You must live in Poland or be willing to relocate to Poland to be considered for this role.).
• Flexible work hours (Each team has their own working habits and obligatory meetings.).
• Workation (up to 10 working days a year within EEA).
• Equity in Company.
• Optional office spaces in Warsaw, Krakow, Wroclaw, Gdansk, or Poznan.
• Home office reimbursement (one-time equipment purchase, internet reimbursement).
• Benefits cafeteria platform.