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

Welo Global; United States; Remote; USD 67,000 - 100,000; Full time

Job summary

Jobicy is seeking a Prompt Engineer to manage end-to-end migration workflows for templates to LLM autoraters. You will leverage internal tools to maximize model performance and ensure high-quality outputs.

Responsibilities include using APG and APO tools, drafting and refining prompts, monitoring shadowbot runs, and validating results against gold data with metrics like F1, precision, and recall. Based in Spain with native Spanish and fluent English.

Qualifications

• Native Spanish and fluent English required.
• Based in Spain.
• Bachelor’s/Master’s/Doctorate in Computer Science, Data Science, Computational Linguistics, HCI, Cognitive Science, or related field.
• 4+ years as a Prompt Engineer with LLM tuning for structured outputs and complex classification.

Responsibilities

• Use APG tools to create baseline prompts for complex templates.
• Monitor APO tool results and flag deadlocks or plateaus.
• Draft, test and refine prompts for edge cases and anti-patterns.
• Monitor shadowbot runs to ensure disagreements are tracked.

Skills

Prompt engineering

Data analysis

SQL

Communication

Technical agility

Education

Bachelor’s/Master’s/Doctorate in CS/Data Science/Computational Linguistics/HCI/Cognitive Science

Tools

Goose API

Proprietary tooling

Job description

We are seeking a Prompt Engineer to be responsible for the end-to-end technical migration workflow for transitioning templates to LLM autoraters. 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 autorater 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.

Requirement:

• Language Skills: Native fluency in Spanish and fluent in English.
• Location: Must be based in Spain.
• 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.

Compensation

Additional Information