AI Senior Engineer - Vision

Back in 2012, we were a group of engineers and designers who decided we wanted to build things—so we did. Keystone AI started as an engineering and product hub building for a portfolio of early-stage startups. We built many relationships while developing products that were thoughtful, effective, and genuinely useful. But, since then, we’ve grown… and so has our ambition. Now, we’re entering our next chapter—defined by applied AI. AI is a powerful force in the end-to-end software development cycle, and we’re creating practices that allow us to deliver software fast and more effectively than traditional approaches, creating meaningful value for our partners. Today, our builder mindset is driving us to become an AI-native organization across every function. We’re still evolving, and that’s part of the opportunity. If you want to build, learn, and tackle challenges alongside an ambitious team, let’s build together. This position is 100% remote within LatAm. What you’ll be doing We are seeking someone who enjoys working at the cutting edge where Computer Vision meets Logic . You will be responsible for the "eyes" and the "brain" of our system—extracting complex data from visual documents and then orchestrating how that data is used by Large Language Models. In short, someone who likes: Unlocking Visual Data: Building pipelines that can "read" complex documents, understanding layout, charts, and visual context using Vision-Language Models (GPT-4V, Claude 3.5) and Layout Analysis . Orchestrating Intelligence: Owning the application logic layer. You will use LangChain or LangGraph to build the agents and chains that query our data, reason about it, and generate responses. Native PDF Handling: Handling the messy reality of PDF processing (PyMuPDF, layout parsing) to preserve structure before the AI even sees it. Prompt Engineering & Logic: Crafting complex prompts and control flows to ensure models interpret financial charts and layouts accurately without hallucinating. Cost & Scale: Applying a cost-optimization mindset (batch processing, model selection) to ensure our vision and orchestration layers are economically viable. What we’re looking for We want to work with people who have a passion for collaborating with their teams, building software while nurturing inclusive and respectful relationships with their coworkers. With the ones that are open about their shortcomings and what they do not know now, but remain eager to keep on growing and closing those gaps. Ideally, they would also have: LLM Orchestration (Must Have ): Deep experience with LangChain, LangGraph, or similar frameworks. You know how to manage context windows, tool calling, and agentic workflows. Multimodal AI Experience: Hands-on experience integrating state-of-the-art vision models (GPT-4V, Claude 3.5 Sonnet) and embedding models (CLIP). Document Intelligence Specialist: Familiarity with specialized models (e.g., Donut, Pix2Struct) and tools like Unstructured.io or Docling. PDF Processing Mastery: Mastery over tools like PyMuPDF or pdfplumber for native element extraction. Python ML Stack: Strong proficiency in PyTorch or TensorFlow. Nice-to-Have: Fine-Tuning: Experience fine-tuning vision or language models, specifically to improve accuracy on domain-specific artifacts like financial charts or tables. Domain Knowledge: Prior experience handling documents in the Real Estate or Finance sectors. Keystone AI is powered by curious, thoughtful people who care about what they build and how they build it. We’re actively investing in our team through AI training, knowledge-sharing, and hands-on experimentation to ensure everyone grows alongside the technology. This position is 100% remote within LatAm. Strong verbal and written communication skills in English are a requirement. As a team member, you can expect: To work 40 hours per week, and be available during normal business hours as needed Payments made in USD 18 days of PTO per year, observance of local holidays, and an annual break between Christmas and New Years A monthly wellness stipend and snack boxes delivered to your home About Keystone AI Keystone AI builds technology products in a portfolio model. We believe that people, teams, and processes are more important than the ideas themselves, so we’ve focused on bringing great people together, and investing in their growth. We’ve built products in a variety of industries. Everything from media to finance to toys to healthcare. Sometimes we work with management teams to help their businesses grow faster or unlock value using technology. Other times we start or buy businesses outright. Each time, we look for opportunities to leverage technology built at the portfolio-level to drive value faster. Keystone AI is committed to inclusion and diversity and is an equal-opportunity employer. All applicants will receive consideration without regard to race, color, religion, gender, gender identity, sexual orientation, national origin, disability, or veteran status. This is but the beginning