Hire the Best Engineering Freelancers
in Spain

Hi, I’m Borja 👋 I’m a versatile professional with a background in QA testing, graphic design, and creative arts. Over the past years, I’ve worked across different fields where precision, creativity, and communication were essential. ✨ What I can help you with: • Design & Creativity: logos, tattoo designs, flyers, posters, and banners — bringing ideas to life with a unique artistic touch. • Technical & Detail-Oriented Work: QA testing, data entry, Excel, Google Docs, and other structured tasks where accuracy matters. • Languages: Fluent in Spanish and English, with basic Indonesian. • Other Skills: Audiovisual Communications Engineer, and over 10 years of experience as a musician (guitarist in a band). I enjoy combining creativity with precision — whether it’s delivering a professional design, organizing information clearly, or ensuring quality in digital projects. I’m also highly adaptable and committed to giving clients reliable results and smooth communication. If you’re looking for someone who can approach your project with both creativity and accuracy, I’d love to collaborate with you.

I am a Top Rated AI Engineer with a PhD in Theoretical Physics. I help companies build private AI systems and workflow automations that can safely work with sensitive business data. If your team wants to use AI on internal documents, customer data, legal/financial information, technical knowledge, or operational workflows, the main question is not “which model should we use?” The real question is: How do we make AI useful without losing control of our data, processes, or infrastructure? I can help with: - Private AI assistants for internal knowledge and document workflows - RAG systems over company documents, databases, tickets, or knowledge bases - Workflow automation for operations, admin, support, legal, or technical teams - Local or private-cloud LLM deployments using open-source models where appropriate - AI readiness and use-case assessment - Production AI pipelines with evaluation, logging, human review, and observability - Inference and infrastructure work for teams needing performance or cost control My background: - Top Rated freelancer on Upwork - PhD in Theoretical Physics - MSc in High-Performance Computing / Machine Learning - AI engineering, data pipelines, RAG, automation, open-source LLMs, and GPU/inference experience Why clients hire me: - I translate business workflows into technical architecture - I care about privacy, control, and maintainability from the beginning - I build practical systems, not demos that break when they meet real data - I can work from strategy and scoping through implementation and deployment Tech stack: Python, PyTorch, Hugging Face, LangChain, LangGraph, RAG, vector databases, vLLM, Docker, Linux, FastAPI, PostgreSQL. Good projects usually start with one painful workflow. If you want to identify, design, or build a private AI system around a real business process, invite me to your job and tell me what workflow you are trying to improve.

💎 𝗧𝗢𝗣 𝗥𝗔𝗧𝗘𝗗 𝐏𝐋𝐔𝐒 💎 Professional 3D product designer with over 10 years of experience, competent, talented, creative, and responsive; these are just some of the feedback from my clients here on Upwork. I produce designs that range from sophisticated and elegant to fun and playful, taking a cue from the client's goals and the intended audience. That’s why my clients keep coming back to me for all their designing needs. ✅ 𝗪𝗵𝗮𝘁 𝘆𝗼𝘂 𝗴𝗲𝘁 𝘄𝗼𝗿𝗸𝗶𝗻𝗴 𝘄𝗶𝘁𝗵 𝗺𝗲: • Photorealistic product renders for e-commerce & marketing • Accurate CAD models for manufacturing & prototyping • Amazon & Shopify-ready 3D assets (GLB, USDZ, OBJ, FBX) • Fast delivery, unlimited revisions & clear communication • AI-enhanced design options (Magnific AI, RunwayLM) 💡 𝗪𝗵𝘆 𝗰𝗹𝗶𝗲𝗻𝘁𝘀 𝗰𝗵𝗼𝗼𝘀𝗲 𝗺𝗲: • Proven experience, 400+ five-star reviews • Creative yet business-oriented approach • Reliable deadlines & responsive communication • 100% satisfaction guarantee (or full refund) 📩 𝗟𝗲𝘁’𝘀 𝗯𝗿𝗶𝗻𝗴 𝘆𝗼𝘂𝗿 𝗽𝗿𝗼𝗱𝘂𝗰𝘁 𝘁𝗼 𝗹𝗶𝗳𝗲! Click on “Invite to Job” at the top of this page, send me a quick note with your idea, and I’ll reply as soon as possible to discuss how we can make it happen.

I help organisations make better decisions through data, analytics, modelling and intelligent systems. My work focuses on understanding business problems, designing practical solutions and implementing systems that improve visibility, planning, efficiency and decision-making. I believe technology should serve the decision, not the other way around. Over the years I have worked across data engineering, analytics, forecasting, optimisation, machine learning and software development. Rather than treating these as separate disciplines, I use them as tools that can be combined depending on the context and objectives of each project. I typically work on projects involving: • Decision support systems and business intelligence solutions. • Data architecture, databases and analytical infrastructure. • Forecasting and scenario analysis for planning and operations. • Optimisation and resource allocation problems. • Process automation and operational efficiency. • Machine learning and AI applications when they create measurable business value. • Custom analytical tools that help teams understand, evaluate and act with greater confidence. My approach is strongly business-oriented. Before discussing technology, I try to understand the context, constraints and decisions that actually matter. The goal is not to build the most sophisticated system possible, but the simplest solution capable of creating meaningful and lasting value. I enjoy working closely with clients, challenging assumptions, exploring alternatives and translating complex situations into clear, actionable decisions. I work fluently in English, Spanish and Catalan and have experience collaborating with international teams across analytical, technical and operational environments. If you are looking for someone who combines analytical rigour, technical capability and a genuine interest in understanding your business, I would be happy to discuss your project.

You're awake at 2am because you’re almost, but not quite, where you want it to be! I've been there a few times on this life journey: 25 years full-stack, twice through to private equity exit. Seed round or series D, same deal: I'm there until it ships. I help across the full project lifecycle: - Prototyping / MVPs / UI&UX - Architecture to production - Project rescue - Legacy modernization - Long-term maintenance

⭐ My Strengths and Skills: ****************************** ✅ Job Success 100% ✅ Verified Freelancer ✅ Upwork Pro & Top Rated Plus ✅ 32K+ Working Hours Mainly, I am focused on (Manual-testing, White-box-testing, Black-Box testing, Performance-testing, Security-testing, Test plan creation, Test case design and writing, Communication with team members, Documentation with a detailed report, and Creating user guides for applications). ⭐⭐ Timeline & Pricing (Looking for Long Term Contract): ******************************************************* ✅ Estimated duration: 2–3 days for initial testing on the pilot phase. ✅ Pricing: Open to fixed price or hourly. ✅ Comfortable starting with a $250-$300 pilot phase testing. ✅ Interested in long-term collaboration if the pilot phase meets your expectations. If you are happy with the pilot phase results, I would be glad to continue long-term, as I am looking for a long-term project. And Using Test Tools: ************************ ● Familiar with the following tools: JIRA, Jenkins/Azure DevOps, Xcode, Android Studio, Postman, and Charles. ● Experience with the following mobile and web test automation frameworks: Espresso, Appium, BrowserStack, LambdaTest, and XCUITest. ⭐ I am following this process during my Testing: ******************************************************** ● Participate in the SCRUM meetings and provide the test estimates. ● Review specifications. ● Creating the test plan and also test cases. ● Identify the test areas and training required. ● Identify the test tools (software and hardware) and maintain them. ● Write and update test cases. ● Perform a sanity test. ● Test new features. ● Complete system test. ● Retest bugs. ● Write a test completion report. ● Keep staging environments up to date. ● Take ownership of the bugs. ● Perform regression testing before each release into production. ● Performance testing (load and stress Testing). ⭐ I am following the processes during my Project Management Role: **************************************************************************** ● Management of Deliverable Schedule and Project Prognosticate ● Maintaining Atlassian JIRA, TestLodge & Confluence, Asana, PivotalTracker, Basecamp ● Communication with team members ● Strategic Quality Planning/Analysis ● Design, Development, and Delivery of End-to-End Testing ● Technical Writing and Documentation ● Requirements Gathering/Business Analysis ✅ Please note that I have the collection of the following DEVICES: ⭐ Apple Devices (iOS 12.0 to iOS latest version 26): *************************************************************** iPhone 17 Pro Max (iOS 26), iPhone 17 Air (iOS 26), iPhone 14 Pro(iOS 18.6), iPhone 15 (iOS 18.3.5), iPhone 16 Pro Max (iOS 26), iPhone 13 Mini(iOS 15), iPhone 6/6 Plus(iOS 15), iPhone 6s/6s Plus(iOS 16), iPhone 7/7 Plus(iOS 15.1), iPhone 8 Plus(iOS 15.3.1), iPad 4(iOS 11.2.1), iPad mini (iOS 12.5), iPad Air (iOS 15.4.5), iPad Pro(iOS 16), iPad 10.2‑inch Retina Display(iOS 15), iPhone XR(iOS 17), iPhone X(iOS 18), iPhone XS Max (iOS 18.0), iPhone 11 Pro Max (iOS 17), iPhone 11 Pro (iOS 18.5), iPhone 11 (iOS 17) ⭐ Android Devices (Android version 7.1.1 to Android 15): ***************************************************************** Galaxy S25 (Android 15), Samsung Galaxy A16 5G (Android v15.0), Pixel 6 with Android 14, OnePlus 9( Android 12), Samsung Galaxy S10+(Android OS 10.0), Google Pixel 3a with Android 12 (Android 13), Google Pixel 2X (Android OS 10.0), Google Pixel XL(Android OS 9.0), Samsung Galaxy S8(Android OS, v9.0 Pie), OnePlus 6T(Android OS, v9.0 Pie), Vivo Y81i(Android OS 8.1.0), LG Nexus 5x(Android OS 8.1.1), OPPO A1K(Android OS 9.0), Nexus 10(Android OS, v7.1.1) ⭐ Other Devices: ********************* Apple Mac, Windows Devices, and ✅YEARLY PLAN✅ with BrowserStack. ⭐ WHY WILL YOU HIRE ME? ********************************* I am an excellent team player who can easily collaborate with various teams/persons like QA Leads, Product Owners, Project Managers, CEOs, Developers, and Others. Finally, I can tell you that I am an honest hard worker for *Quality*, passionate, extremely enthusiastic, and exceptional with a specific deadline. I feel confident that my skills and experience make me the perfect candidate for a QA job. So, I can assure you that I am the perfect fit for the QA/Manager role, and you can rely on me. ✅ Testing is the best policy for ensuring better quality! So thinking the best, forget the rest! 👌