Full-Stack Developer - AI Trainer (Remote in Spain)

Anyone AISpainNew

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Qualifications

Qualifications:Fluent in written English with advanced professional proficiency3 to 7 years of experience in software engineeringExpertise in Python and JavaScript/TypeScript; familiarity with Java, C#, or Go is a plusExperience in backend or full-stack development within production environmentsKnowledge of testing frameworks such as pytest, Jest, JUnit, xUnit, or Go testingProficient in debugging and navigating extensive multi-file codebasesExperienced in conducting code reviews, refactoring, and managing production migrations

About the job

Join Anyone AI, where we're on the lookout for talented Full-Stack Developers to collaborate on innovative projects with a leading AI laboratory. This is an exciting opportunity to be at the forefront of AI technology.

About Anyone AI

Anyone AI is dedicated to pushing the boundaries of artificial intelligence, offering a collaborative environment where innovation thrives. Work with top-tier professionals and engage in projects that make an impact.

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Backend Developer - AI Trainer

anyone-ai

Full-time|Remote|Spain

Role Overview anyone-ai is looking for a Backend Developer - AI Trainer based in Spain. This role focuses on building and improving backend systems that support AI training projects. What You Will Do Develop and refine backend infrastructure to support AI model training and deployment. Work closely with team members to optimize systems for real-world AI appl…

Apr 13, 2026

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Backend Developer - AI Trainer in Spain

Anyone AI

Contract|Remote|Spain

Anyone AI seeks experienced Backend Developers based in Spain to support a high-profile AI laboratory project. This remote, part-time role centers on expert evaluation tasks and the creation of realistic software engineering exercises. Role overview As a Backend Developer - AI Trainer, the primary focus is on designing and assessing complex coding challenges. Tasks include bug fixes, feature development, refactoring, migrations, and test generation. The position involves both creating coding scenarios and reviewing peer submissions for accuracy and quality. Responsibilities Design and implement multi-file coding assignments covering bug resolution, new features, refactoring, and testing Write clear, natural-language specifications and provide reference implementations Develop and improve unit and integration test suites Review and evaluate peer-generated tasks for correctness, clarity, and realism Identify edge cases, ambiguities, and potential failure points Ensure alignment between specifications, code, and expected results Requirements Exceptional written English skills 3–7 years of experience in software engineering Advanced proficiency in Python and JavaScript or TypeScript; familiarity with Java, C#, or Go is a plus Background in backend or full-stack development within production settings Knowledge of testing frameworks such as pytest, Jest, JUnit, xUnit, or Go testing Strong debugging skills and the ability to navigate large, multi-file codebases Experience with code reviews, refactoring, and production migrations Engagement details Part-time, project-based work Remote from anywhere in Spain Expected outcomes Deliver high-quality, production-ready coding tasks that meet industry standards

Apr 29, 2026

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Full-Stack Developer - AI Trainer in Spain

anyone-ai

Full-time|Remote|Spain

About the Role anyone-ai is looking for a Full-Stack Developer focused on AI training. This position is based in Spain. The role calls for experience across both front-end and back-end development to build and support software that helps train AI systems. What You Will Do Design, code, test, and maintain software applications that support AI training projects Work with cross-functional teams to improve user experiences Contribute to both front-end and back-end solutions Location This is a Spain-based position.

Apr 14, 2026

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Full-Stack Developer - AI Trainer (Remote in Spain)

Anyone AI

Contract|Remote|Spain

May 4, 2026

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Freelance n8n Workflow Developer - AI Trainer

Mindrift

Part-time|$50/hr - $50/hr|Remote|Remote — València, Valencian Community, Spain

Mindrift is seeking freelance n8n Workflow Developers to support the Tendem project. This part-time, remote contract role is open to candidates based in València, Valencian Community, Spain, as well as those working remotely. As an AI Pilot, you will focus on designing and improving automation workflows that combine AI capabilities with human expertise. The work centers on building, optimizing, and maintaining automation pipelines in self-hosted n8n environments. Projects frequently involve integrating several systems and AI features to create scalable, reliable processes. What you will do Design, build, and evaluate complex workflows within self-hosted n8n setups. Develop integrations connecting multiple systems to enable robust automation pipelines. Create and refine AI-driven workflows for tasks such as content generation, automation, and data enrichment. Set up and manage automated processes for lead generation, outreach, and data processing. Implement web scraping workflows to accurately extract and process data. Enhance workflow execution, node sequencing, and error handling to minimize failures, delays, and API timeouts. Compensation Contributors may earn up to $50 per hour, depending on experience and the speed of contributions. Actual pay will vary based on the specifics of each project. This role is part of Mindrift’s mission to connect skilled professionals with AI initiatives from leading technology innovators. As part of the Tendem project, you will collaborate with Tendem Agents who manage repetitive tasks, using your automation skills to improve workflow efficiency and reliability. For more information on the Tendem project, visit https://tendem.ai/.

Apr 25, 2026

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Creative Python Backend Developer for AI Solutions

TransPerfect

Full-time|Hybrid|Malaga, Andalucía, Spain

About Us:TransPerfect is a leading provider of translation software with a dynamic and innovative start-up culture. We are on the lookout for a passionate and inventive Backend Developer to join our groundbreaking Artificial Intelligence (AI) team. As a member of this division, you will play a pivotal role in shaping the future of AI within a globally recognized organization. Our AI team, which has evolved over the past decade since the inception of our first machine translation models, is a key driver of innovation in machine translation, generative AI, natural language processing, and automation.We seek an experienced backend developer who is enthusiastic about exploring the limits of technology and making a meaningful impact in the AI domain. You will collaborate with a diverse, global team of professionals from the USA, Spain, Portugal, and India. If you have a strong passion for building robust and scalable solutions that deliver AI capabilities to users, this is the perfect opportunity for you.About the Role:As a Backend Developer, you will address the challenges of document processing, specifically converting complex, unstructured PDFs into well-formatted, editable .docx files. Your objective will go beyond simple text extraction; you will aim to faithfully recreate the visual and structural intent of the original documents, including nested tables, multi-column layouts, font hierarchies, and styling.In this hybrid role, you will lead the research and implementation of our document conversion pipeline. This position requires both strategic decision-making—keeping abreast of existing tools—and hands-on development, blending engineering and AI expertise.You will be responsible for:Comparative Analysis: Conducting comprehensive evaluations of commercial (e.g., ABBYY, Adobe, AWS Textract) versus open-source/AI-native (e.g., Mistral OCR, Docling, Nougat, LlamaParse) solutions.Benchmarking: Establishing metrics for "format fidelity" to objectively assess how effectively a tool reproduces headers, footers, tables, and styles.Pipeline Development: Developing a Python-based workflow that integrates OCR engines with document generation libraries (such as python-docx or Pandoc).

Mar 10, 2026

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Senior Python Backend Developer for AI Solutions

TransPerfect

Full-time|Hybrid|Malaga, Andalucía, Spain

About us:TransPerfect, a leading name in translation technology, is on the lookout for a dynamic and innovative Backend Developer to join our cutting-edge Artificial Intelligence (AI) team. As part of this division, you will have the chance to influence the future of AI within a global framework. Over the past decade, our AI team has evolved into a pivotal force driving innovations in machine translation, generative AI, natural language processing, and automation.We seek an experienced backend developer who is passionate about pushing technological boundaries and making a significant impact in the AI sector. You will collaborate with a diverse, international team of experts from the USA, Spain, Portugal, and India. If you are enthusiastic about developing robust and scalable solutions that enhance AI accessibility, this role is perfect for you.About the Role:As a Backend Developer, you will tackle the critical challenge of transforming complex, unstructured PDFs into well-formatted, editable .docx files. Your mission will be to not only extract text but to faithfully recreate the visual and structural elements of the original documents, including nested tables, multi-column layouts, font hierarchies, and styling.Your responsibilities will include leading the research and implementation of our document conversion pipeline. This hybrid role requires both strategic decision-making regarding existing tools and hands-on development that combines engineering with AI expertise.Responsibilities Include:Comparative Analysis: Conduct thorough evaluations of commercial solutions (e.g., ABBYY, Adobe, AWS Textract) versus open-source/AI-native alternatives (e.g., Mistral OCR, Docling, Nougat, LlamaParse).Benchmarking: Define metrics for

Mar 10, 2026

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Civil Engineer & Python Specialist - Freelance AI Trainer

Toloka AI

Contract|Remote|Remote — València, Valencian Community, Spain

Toloka AI seeks a freelance AI trainer with experience in civil engineering and Python programming. This role focuses on training AI systems by combining technical engineering knowledge with hands-on coding skills. Responsibilities Use civil engineering expertise and Python programming to support AI training projects. Handle a variety of assignments that help advance AI technology. Collaborate with an international team while working remotely. Location This position is fully remote, based in València, Valencian Community, Spain.

Apr 28, 2026

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AI Software Engineering Trainer - Spain

anyone-ai

Full-time|On-site|Spain

Join anyone-ai as an AI Software Engineering Trainer, where you will play a pivotal role in shaping the future of AI education. Your expertise in software engineering and AI technologies will help guide aspiring professionals in mastering cutting-edge methodologies.As part of our innovative team, you will be responsible for developing and delivering training programs, creating engaging content, and mentoring participants to achieve their career goals in AI.

Mar 25, 2026

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Freelance Mathematics Expert - AI Trainer

Toloka AI

Contract|Remote|Remote — València, Valencian Community, Spain

Toloka AI seeks a Freelance Mathematics Expert to serve as an AI Trainer. This fully remote position is based in València, Valencian Community, Spain, and allows work from any location. Key responsibilities Create mathematics-focused learning materials for AI education Develop training resources to support AI system development Review and verify the accuracy of AI algorithms and related documentation Collaboration and impact This role involves close collaboration with a team dedicated to advancing AI. Contributions in this position help shape how AI systems learn and apply mathematical concepts in real-world scenarios.

Apr 27, 2026

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Freelance English Writer - AI Trainer

Toloka AI

Contract|Remote|Remote — València, Valencian Community, Spain

Toloka AI seeks a Freelance English Writer - AI Trainer to support the development of artificial intelligence systems. This is a remote position based in València, Valencian Community, Spain. Role overview This role centers on producing well-crafted English text for AI training projects. The writing produced will directly influence how AI models interpret and generate language. What you will do Write clear, accurate English content for use in training artificial intelligence systems Contribute to projects that require careful attention to language quality and clarity Location This position is remote, but candidates should be based in València, Valencian Community, Spain.

Apr 27, 2026

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Freelance Junior Journalist - AI Trainer

Toloka AI

Contract|Remote|Remote — València, Valencian Community, Spain

Toloka AI seeks a Freelance Junior Journalist - AI Trainer to join projects focused on artificial intelligence. This is a remote position, available to candidates based in València, Valencian Community, Spain. Key responsibilities Collaborate with teams to produce clear and engaging content that supports AI development. Help train AI models by supplying relevant materials and offering feedback. Location details This role is fully remote but requires residence in València, Valencian Community, Spain.

Apr 27, 2026

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Freelance AI Trainer: Physics Specialist with Python Expertise

Mindrift

Part-time|$29/hr - $29/hr|Remote|Remote — València, Valencian Community, Spain

Please submit your CV in English and indicate your level of English proficiency.Mindrift is an innovative platform that connects talented specialists with project-based AI opportunities for prominent tech companies, emphasizing the testing, evaluation, and enhancement of AI systems. This is a project-based role, not a permanent position.Opportunity OverviewEach project presents unique challenges, and contributors may be involved in the following tasks:Crafting original computational physics problems that mirror authentic physics research workflows;Developing problems that necessitate Python programming solutions (using libraries such as Numpy, SciPy, Sympy);Ensuring problems are computationally demanding and cannot be resolved manually within reasonable timeframes (days/weeks);Creating problems that require intricate reasoning chains in areas such as mechanics, electromagnetism, thermodynamics, and quantum mechanics;Grounding problems in real-world research challenges or practical applications from the field of physics;Validating solutions using Python alongside standard physics simulation libraries;Clearly documenting problem statements and providing verified correct answers.Ideal Candidate ProfileThis role is well-suited for physicists with Python expertise seeking part-time, project-based work. The ideal candidate will possess:A degree in Physics (Theoretical, Experimental, or Computational) or related fields;Proficiency in Python for numerical validation; familiarity with MATLAB, R, C, SQL, Numpy, Pandas, SciPy, or any programming language is acceptable;At least 2 years of professional experience in applied physics, research, or teaching;Experience with numerical simulation methods;The ability to design problems that replicate real physics research workflows;Creative problem-solving skills across various physics domains;Knowledge of physics modeling and approximation techniques;Strong written English skills (C1 or higher).Application ProcessTo apply, follow these steps: Submit your application → Pass the qualification assessments → Join a project → Complete assigned tasks → Receive payment.Project CommitmentDuring active phases of projects, tasks are expected to require around 10–20 hours per week, depending on the specific project requirements. Note that this is an estimate and not a guaranteed workload.CompensationContributors can earn up to $29 per hour, contingent upon their level of expertise and contribution speed. Compensation may vary based on project scope, complexity, and required skills. Please be aware that other projects may offer different compensation rates depending on their specific needs.

Apr 30, 2026

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AI Software Engineering Trainer - Remote Opportunity in Spain

Anyone AI

Contract|Remote|Spain

Role overview Anyone AI seeks experienced software engineers to serve as AI Software Engineering Trainers. This is a remote, part-time consulting position for candidates based in Spain. Trainers collaborate with a prominent AI laboratory, shaping authentic engineering tasks and evaluating solutions for technical quality and depth. What you will do Create and implement multi-file coding challenges that cover bug fixes, new features, refactoring, and test development. Write clear, thorough specifications along with reference implementations. Develop and expand unit and integration test suites. Review peer-created tasks for technical accuracy and clarity. Identify edge cases, ambiguities, and potential failure points in both code and requirements. Ensure alignment between specifications, code, and expected outputs. Expected outcomes Deliver solutions that are production-ready and meet recognized industry standards. Requirements Exceptional written English for professional communication. 3 to 7 years of hands-on software engineering experience. Proficiency in Python and JavaScript or TypeScript. Knowledge of Java, C#, or Go is a plus. Background in backend or full-stack development for production environments. Experience with testing frameworks such as pytest, Jest, JUnit, xUnit, or Go testing tools. Ability to work with large, multi-file codebases and debug complex issues. Track record of code reviews, refactoring, and managing production migrations. Engagement details Part-time, project-based consulting arrangement. Fully remote role based in Spain.

Apr 20, 2026

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Senior Backend Developer

SGS

Full-time|On-site|Madrid

Join our dynamic team as a Senior Backend Developer at SGS in Madrid, where you will play a pivotal role in advancing our backend architecture and driving a culture of technical excellence. We are seeking an individual with exceptional technical leadership abilities who can serve as a guiding force for our engineering team. You will have ownership over our backend platform and be instrumental in enhancing code quality and engineering standards.In this role, you will work on a cutting-edge SaaS platform developed on .NET 10, primarily leveraging Azure PaaS. Our work environment is international and English-speaking, fostering collaboration across diverse teams.Key Responsibilities:Design, develop, and enhance scalable, secure, and maintainable backend systems.Lead development initiatives, making impactful architectural and technical decisions.Act as a technical mentor and resource for team members, fostering their growth.Manage the complete software lifecycle— from conceptualization and design to deployment, monitoring, and iterative improvement.Integrate with modern and legacy systems seamlessly.Collaborate with product, frontend, and DevOps teams to create comprehensive end-to-end solutions.Promote engineering excellence by advocating for best practices, including Clean Code and SOLID principles.Architect and deploy distributed systems and event-driven architectures.Construct and refine CI/CD pipelines to facilitate rapid, reliable delivery.Ensure system reliability, performance, and observability in live production environments.Guide and support fellow developers through code reviews, knowledge sharing, and technical mentorship.Contribute to technical documentation, ensuring effective knowledge transfer within the team.

May 4, 2026

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Freelance AI Trainer - Statistics & Python Specialist

toloka-ai

Part-time|$34/hr - $34/hr|Remote|Remote — València, Valencian Community, Spain

Please submit your CV in English and indicate your level of English proficiency.At Mindrift, we bridge the gap between specialists and innovative AI projects for top technology companies, focusing on the evaluation, testing, and enhancement of AI systems. This is a project-based engagement, not a permanent position.Opportunity OverviewEach project presents distinct tasks, with potential responsibilities including:Creating original computational statistics problems that mimic real-world mathematical research workflows;Formulating problems that necessitate Python programming solutions (utilizing libraries such as Numpy, SciPy, Sympy);Ensuring that problems are computationally intensive and cannot be manually resolved in a reasonable time frame (days/weeks);Developing problems that require complex reasoning chains in fields such as number theory, combinatorics, graph theory, and numerical analysis;Grounding problems in actual research challenges or practical mathematical applications;Validating solutions using Python and standard mathematical libraries;Clearly documenting problem statements and providing verified correct answers.Qualifications We SeekThis role is ideal for statistics specialists with Python expertise, who are interested in part-time, non-permanent projects. Preferred qualifications include:A degree in Statistics or a related field;Proficiency in Python for numerical validation; familiarity with MATLAB, R, C, SQL, Numpy, Pandas, SciPy, and domain-specific libraries may be equivalent;A minimum of 2 years of professional experience, including applied, research, or teaching backgrounds;Strong written English skills (C1 or higher);Professional certifications (e.g., CMME, SAS Certifications, CAP) and experience in international or applied projects are advantageous.How the Process WorksSubmit your application → Complete qualification requirements → Join a project → Execute tasks → Receive payment.Project Time CommitmentFor this project, active tasks are estimated to require approximately 10–20 hours per week, varying based on specific project demands. This is an estimate and not a guaranteed workload.CompensationContributors can earn up to $34 per hour, depending on their expertise level and contribution pace. Compensation may vary across projects based on scope, complexity, and required skills. Note that other projects on our platform may feature different earning potentials based on their criteria.

Apr 30, 2026

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Freelance AI Trainer - Data Scientist (Python & SQL)

toloka-ai

Contract|$34/hr - $34/hr|Remote|Remote — València, Valencian Community, Spain

Please submit your CV in English and indicate your English proficiency level. This freelance, project-based contract connects data scientists with AI assignments for top technology companies. The work centers on designing and validating computational challenges that mirror real-world analytics in industries such as telecom, finance, government, e-commerce, and healthcare. This is not a permanent position. Key Responsibilities Design data science problems that reflect authentic analytical workflows and business scenarios, including customer analytics, risk assessment, fraud detection, forecasting, optimization, and operational efficiency improvements. Develop computationally intensive challenges that require Python programming, using libraries like Pandas, Numpy, Scipy, Sklearn, Statsmodels, Matplotlib, and Seaborn. Write tasks involving advanced reasoning in data processing, statistical analysis, feature engineering, predictive modeling, and extracting actionable insights. Ensure all problems are deterministic and reproducible, using fixed seeds for any random elements. Design end-to-end projects spanning the full data science lifecycle: data ingestion, cleaning, exploratory data analysis (EDA), modeling, validation, and deployment considerations. Incorporate big data processing elements that require scalable computational solutions. Validate solutions in Python with standard data science libraries and statistical techniques. Document each challenge clearly within a business context and provide verified, correct answers. Location This role is remote and based in València, Valencian Community, Spain.

Apr 25, 2026

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Freelance AI Trainer - Research Physicist with Python Expertise

Toloka AI

Part-time|$29/hr - $29/hr|Remote|Remote — València, Valencian Community, Spain

Please submit your CV in English and indicate your level of English proficiency. Mindrift connects specialists with project-based AI opportunities for leading tech companies, focusing on testing, evaluating, and enhancing AI systems. This role is project-based and does not offer permanent employment.Opportunity OverviewEach project presents distinct tasks, which may include:Crafting original computational physics problems that emulate authentic physics research workflows;Formulating problems that necessitate Python programming for resolution (utilizing Numpy, SciPy, Sympy);Ensuring challenges are computationally intensive, requiring more than just manual solutions within reasonable timeframes (days/weeks);Designing problems that demand intricate reasoning in mechanics, electromagnetism, thermodynamics, and quantum mechanics;Utilizing real research challenges or practical applications from the field of physics as the foundation for problems;Validating solutions through Python and standard physics simulation libraries;Providing clear documentation of problem statements along with verified correct answers.Ideal Candidate ProfileThis opportunity is well-suited for physicists with Python expertise who are open to part-time, non-permanent projects. Preferred qualifications include:A degree in Physics (Theoretical, Experimental, or Computational) or related disciplines;Proficiency in Python for numerical validation; familiarity with MATLAB, R, C, SQL, Numpy, Pandas, SciPy, and other domain-specific libraries is also acceptable;A minimum of 2 years of professional experience, including applied, research, or teaching roles;Experience with numerical simulation techniques;Capability to design problems that reflect actual physics research workflows;Inventive problem design across various physics domains;Understanding of physics modeling and approximation strategies;Strong written English skills (C1 or above).Application ProcessApply → Pass qualifications → Participate in a project → Complete assigned tasks → Receive payment.Project CommitmentTasks are anticipated to require approximately 10–20 hours per week during active phases, based on project needs. This is an estimate and not a guaranteed workload, applicable only during active project periods.Compensation DetailsContributors may earn up to $29 per hour, contingent upon their level of expertise and contribution pace. Note that compensation may vary across projects depending on their scope, complexity, and required skill sets.

Apr 30, 2026

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Biology and Python Specialist - Freelance AI Trainer Position

Toloka AI

Contract|Remote|Remote — València, Valencian Community, Spain

Toloka AI is seeking a freelance specialist with a strong background in biology and Python programming. This remote role is based in València, Valencian Community, Spain. Role overview This position centers on training AI systems using knowledge from both biological sciences and Python. The work involves applying subject matter expertise to support the development and accuracy of AI models. What you will do Use your understanding of biology to inform AI training tasks Apply Python skills to support technical aspects of the training process Communicate complex ideas in clear, accessible language Requirements Expertise in biological sciences Proficiency in Python programming Ability to explain technical and scientific concepts effectively

Apr 29, 2026

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Freelance Electrical Engineer & Python Specialist - AI Trainer

toloka-ai

Part-time|$31/hr - $31/hr|Remote|Remote — València, Valencian Community, Spain

We invite you to submit your CV in English, along with your level of English proficiency.Mindrift connects talented professionals with project-based AI opportunities for top technology companies, focusing on the testing, evaluation, and enhancement of AI systems. This is a project-based engagement, not a permanent position.Opportunity OverviewEach project presents unique challenges, and contributors may be involved in tasks such as:Crafting original computational engineering problems that emulate real-world engineering processes;Developing programming challenges using Python to carry out engineering calculations and simulations;Ensuring that problems are computationally demanding and necessitate numerical methods or iterative solutions;Creating scenarios involving system design, optimization, and analysis;Formulating problems based on genuine research challenges or real-world engineering applications;Validating solutions using Python with standard engineering libraries;Clearly documenting problem statements and providing verified correct answers.Candidate ProfileThis role is suitable for engineers with experience in Python, looking for part-time, non-permanent project work. Ideal candidates will possess:A degree in Electrical Engineering or related disciplines;Proficiency in Python for numerical validation. Familiarity with MATLAB, R, C, SQL, Numpy, Pandas, SciPy, or any programming language is acceptable;At least 2 years of professional experience, including applied, research, or teaching roles;A solid understanding of practical engineering limitations and approximations;Excellent written English skills (C1 or higher);Professional certifications (e.g., CMME, SAS Certifications, CAP) and experience with international or applied projects is a plus.Application ProcessApply → Pass qualifications → Join a project → Complete tasks → Get compensatedProject Time CommitmentTasks for this project are estimated to require approximately 10-20 hours per week during active phases, depending on project demands. This is an estimate and not a guaranteed workload.CompensationParticipants can earn up to $31 per hour, based on their experience and contribution pace. Compensation varies across different projects based on scope, complexity, and required expertise. Please note that other projects on the platform may offer different compensation levels based on their specific requirements.

Apr 30, 2026

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