Senior Backend API Engineer

Spike Technologies Inc . is a hyper growth B2B Agentic AI and health data startup founded in 2022, split between San Francisco, California, and Vilnius, Lithuania. The company serves a diverse client base across healthcare, government, digital health and health insurance sector. In July 2026 Spike Technologies was acquired by Raintree, leading EMR platform in US rehab industry! Spike Technologies is looking for an experienced backend developer to join our team in building cutting-edge Data Engineering and Generative AI technology. In this role, you will be responsible for the development of scalable systems that serve our enterprise clients in the HealthTech industry. You'll be working with billions of proprietary data points derived from Wearables, IoT devices, other sensors and will be building microservices infrastructure to deliver this structured data feed and GenAI insights for our clients near-real-time. Responsibilities: Contribute to the development of scalable backend systems Implement a large variety of data sources Build supporting microservices Work with messaging/queuing systems Maintain and optimize existing systems Contribute to the design and implementation of new data engineering features Work with the data engineering team on bridging the Spike ETL product and backend / UI Work with the data team to generate custom metrics for system security, usability and visibility for clients Work with the data team on the infra components for the Spike Generative AI product Qualifications: 5+ years of experience in backend software development Advanced knowledge of one or more object-oriented programming languages. For the reference, our tech stack is as follows: AWS, Python, Golang, Typescript, Kubernetes, Postgres Experience working with messaging/queuing systems Working knowledge of relational databases Good to have: Experience with Kubernetes and Docker Experience with AWS or other cloud provider Experience with systems design Experience in MLOps Ability to move fast as it's part of Spike's culture What we offer: Competitive salary in the range of 4,500 to 8,000 eur gross (and more in exceptional cases) per month depending on your qualifications. Annual bonus. Hybrid working model (offices in Vilnius, Lithuania and Palo Alto, CA) Personal health fund, optical allowance, referral bonus, team events. Dynamic growth: dive into AI and Data tech, seizing high-growth opportunities with cutting-edge projects. Talented peers: collaborate with a smart, ambitious team comprising data scientists, PhDs, Cambridge alumni, and tech industry pros (formerly from Bloomberg, Amazon, and Google). Solid backing: enjoy stability and ample resources for success, supported by market leader Raintree. At Spike Technologies, diversity is celebrated, and inclusion is our priority. We welcome applicants from all backgrounds to join our innovative team and contribute to our inclusive culture. Sounds like you? Let's talk. At Raintree, we’re not just shaping the future of therapy technology – we’re creating it. This is your chance to be part of something bigger, where your career will have game-changing, career-defining moments that propel you to new heights. We aim to be the best place for the best people , and we’re looking for ambitious, creative thinkers ready to make an impact. Whether you’re advancing AI solutions or enhancing user experiences, your work here will shape the future of therapy technology while advancing your career alongside dedicated professionals who are as committed to your success as you are. At Raintree, your ideas drive real change, your growth is limitless, and the work you do will touch millions of lives. Ready to ignite your career and leave a lasting legacy? Join us and be part of something extraordinary. Our Core Values We put our Clients First - We are Open and Honest - We are Disciplined, Yet Flexible We love to Solve Problems - We are Committed to Greatness - We are a High Performance Team Raintree Systems provides equal employment opportunities to all employees and applicants for employment and prohibits discrimination and harassment of any type without regard to race, color, religion, age, sex, national origin, disability status, genetics, protected veteran status, sexual orientation, gender identity or expression, or any other characteristic protected by federal, state or local laws.