Remote Senior Full-stack role focused on building and maintaining veterinary SaaS using Elixir (or Erlang/other functional language) for back end and React for front end. Responsibilities include end-to-end ownership from scoping to release, designing scalable solutions, working with GraphQL and relational databases, mentoring junior engineers, collaborating with product/QA, and troubleshooting complex customer issues. Located in Latin America; requires fluent English and 5+ years building modern SaaS applications.