Staff Software Engineer - Backend

Leona is on a mission to empower everyone to take the best care of themselves, their patients, and their loved ones. We have an ambitious goal: to transform the way the world interacts with healthcare. We strongly believe that where you live shouldn’t impact your access to high-quality care. For patients, it should feel empowering, and unintimidating, to proactively take care of yourself and your loved ones. For doctors, we want to enable you to focus on what matters most, delivering the best possible care, by providing better tooling, decreasing the administrative burden, and helping you to prioritize based on urgency and complexity while saving time and improving clinician quality of life.
We are reimagining how doctors provide care for their patients in an AI-first world. Our first product is a platform that streamlines Doctor-Patient communication via WhatsApp. Leona is designed to act as a doctor’s AI clinical assistant, automating and delegating non-urgent tasks, while allowing patients the convenience of reaching their doctors 24/7 via WhatsApp.
With bases in San Francisco and Mexico City, our diverse team brings together years of experience scaling tech companies like Rappi, Uber, Modern Fertility and Wonder throughout the US and Latin America. Leona is backed by top-tier investors such as General Catalyst, and Accel, as well as an incredible list of angel investors including the founders of Nubank, Rappi, Maven Clinic, and other successful technology companies.

If you are hungry to learn and build 0-1 at an early stage startup, while rolling up your sleeves to make some magic, this role might be the perfect fit for you!

We’re looking for an experienced software engineer to help us shape and scale Leona. Leona is reimagining how the world interacts with care — starting with doctor-patient communication on WhatsApp. We are building an an AI-powered platform that automates clinical workflows to empower doctors to save time, reduce burnout, and deliver better, more personalized care at scale. Patients today expect round-the-clock access to personalized care, but doctors are stuck with outdated, fragmented tools; Leona bridges that gap with intelligent automation and seamless messaging. If you’re driven by tough engineering and user experience challenges, love wearing many hats, and thrive in taking products from 0 to 1, this role is for you.

• Take full ownership of projects that are both technically complex and business-critical

• Collaborate closely with design, operations, data science, and medical professionals to deliver impactful product experiences

• Work side-by-side with our CTO to evolve our engineering strategy and improve how we build

• Help shape technical direction and product decisions as a core member of a small, high-performing team

• 6+ years of relevant experience, with a strong track record of building and scaling complex software systems (startup experience is a plus!)

• Deep expertise in backend development using modern technologies (we use Python on the backend; clients are built in Flutter), and familiarity with managing production-scale infrastructure within AWS

• Comfortable working across the stack and owning projects end-to-end — from idea to launch to scale

• Strong understanding of modern AI technologies — you stay current with the tooling landscape and confidently apply AI/ML to real-world problems

• Excellent communication and collaboration skills

• A builder’s mindset and love for creating things that make a difference

We’d love to work with someone who:

• Thrives in ambiguity and fast-moving environments

• Loves collaborating with talented cross-functional teammates

• Is energized by the challenges and opportunities of early-stage startups

• Is mission-driven and passionate about improving health outcomes

• Is curious, resourceful, and always looking to innovate

Bonus points for:

• Experience in health tech or building communication tools (messaging, collaboration, etc.)

• Spanish fluency