Project Lion - Senior Prompt Engineer - Germany (Remote, Part-Time)

Welo Global; Germany (OH); Remote; USD 70,414 - 105,621; Full time

Job summary

Welo Global is seeking a Prompt Engineer responsible for the technical migration workflow and optimizing Large Language Models (LLMs). The ideal candidate must have native fluency in German and fluency in English, with a relevant degree and at least 4 years of experience in prompt engineering. Responsibilities include utilizing prompt generation tools, supervising optimization processes, and refining prompts for complex scenarios. This role is critical in ensuring model performance and requires strong data analysis skills.

Qualifications

• Minimum 4 years' experience as Prompt Engineer.
• Proven experience tuning LLMs for structured outputs.
• Strong proficiency in identifying error patterns and analyzing model performance.

Responsibilities

• Utilize APG tools to create prompts for template clusters.
• Supervise Automatic Prompt Optimization tool and review outputs.
• Manually draft and refine prompts for complex template architectures.

Skills

Native fluency in German

Fluent in English

Data analysis

Communication skills

Technical agility

Education

Bachelor’s, Master’s, or Doctorate degree in Computer Science, Data Science, Computational Linguistics, HCI, or related field

Tools

SQL

APG tools

APO systems

Job description

We are seeking a Prompt Engineer to be responsible for the end-to-end technical migration workflow for transitioning templates to LLM authorators. The role is required to use client’s internal tools to leverage prompt engineering techniques to maximize model performance.

Responsibilities

• Utilize Automatic Prompt Generation (APG) tools to create baseline prompts for complex parent-child template clusters.

• Run and supervise Automated Prompt Optimization (APO) tool, review the outputs, and flag when the APO reaches deadlocks or plateaus.

• Manually draft, test, and refine prompts to navigate complex template architectures, overcome anti-patterns, and handle edge cases where tooling is lacking or broken. Solve edge-case scenarios by designing and refining manual prompts.

• Monitor shadowbot runs to ensure sufficient disagreements (between human and LLM ratings) are registered, generated, and tracked.

• Run prompt versions against established gold data to continuously measure authorator quality against the human crowd baseline, calculating accuracy metrics such as F1 scores, precision, and recall.

• Draft technical launch readiness justifications (Launch Certification Documentation) for final.

Requirements

• Language Skills: Native fluency in German and fluent in English.

• Location: Must be based in Germany.

• Education: Bachelor’s, Master’s, or Doctorate degree in Computer Science, Data Science, Computational Linguistics, Human-Computer Interaction (HCI), Cognitive Science, or a related analytical field.

• Prompt Engineering & AI Expertise: At least 4 years' experience as Prompt Engineer. Proven experience tuning Large Language Models (LLMs) for strict, structured outputs, complex classification tasks, and familiarity with chain-of-thought and few-shot learning.

• Data Analysis: Strong proficiency in identifying error patterns, analyzing model performance, and using SQL or other data analytics tools.

• Technical Agility: Ability to quickly learn and master proprietary tools with minimal supervision.

• Communication: Excellent verbal and written communication skills.

Optional / Preferred Skills

• Familiarity with enterprise-grade LLM interfaces like the Goose API.

• Experience in AI model evaluation, data science, computational linguistics, or software engineering.

• Hands‑on experience with Automated Prompt Optimization (APO) systems or tuning workflows.

• Linguistic expertise, including an understanding of semantics and logic.