Senior Software Development Engineer

Senior Software Engineer Employee Location: Boulder, CO, relocation stipend available Reporting To: Chief Technology Officer Job Type: Full-time, Hybrid in office Boulder, CO Work Authorization: Applicants must have legal authorization to work in the U.S. without the need for current or future sponsorship BranchLab is transforming healthcare commercialization with Pathwai™, the industry's first Semantic Activation Platform. Our AI-native technology helps leading healthcare organizations and their agencies make smarter commercialization decisions and connect patients, providers, and caregivers to life-improving therapies and resources. Built for the evolving privacy landscape, BranchLab improves commercialization performance without relying on individual-level health information. By modernizing the industry's technical infrastructure, we help organizations operate more efficiently and responsibly while improving how healthcare audiences are understood, reached, and engaged. BranchLab is helping build a more intelligent, efficient, and responsible model for healthcare commercialization. The Opportunity We're looking for a backend-focused Senior Software Engineer to join our Boulder-based team and help architect and build the systems powering our privacy-first, data-driven platform. This is a highly hands-on role combining backend engineering, distributed systems, data infrastructure, and cloud-native development. You'll own significant parts of the platform, designing scalable systems to process, transform, and query large volumes of anonymized healthcare data and building the services that turn that data into insights and downstream applications. We're looking for someone who can operate as both a strong individual contributor and a technical leader. You'll continue to design and write production code while also leading small teams or project workstreams, helping break down complex initiatives, coordinating execution, mentoring engineers, and driving technical decisions through delivery. Key Responsibilities Design, build, and own backend systems and APIs using Python. Build and optimize large-scale data-processing pipelines using Apache Spark. Design systems for ingesting, transforming, aggregating, and querying large datasets. Architect and operate distributed workloads on AWS using technologies such as EKS, EMR, and Airflow. Lead small engineering teams or project workstreams while remaining a hands-on contributor. Break down complex initiatives, drive technical decisions, coordinate execution, and help remove blockers. Mentor engineers through design reviews, code reviews, debugging, and day-to-day technical guidance. Improve the reliability, scalability, performance, security, and observability of production systems. Qualifications Strong backend software engineering experience, particularly with Python. Significant hands-on experience building and optimizing production data pipelines with Apache Spark. Experience processing large datasets in distributed environments and strong SQL skills. Experience with cloud-native systems, ideally AWS, including technologies such as Kubernetes, EMR, S3, and Athena. Experience with workflow orchestration tools such as Apache Airflow. Strong understanding of distributed systems, data processing, performance, and reliability. Experience leading technical projects or small engineering teams while remaining a hands-on contributor. Strong technical judgment, communication skills, and a pragmatic approach to building maintainable production systems. Nice-To-Haves Previous experience as a tech lead, team lead, or hands-on engineering manager. Experience with infrastructure-as-code and CI/CD. Experience with data lakes, Snowflake, Databricks, or streaming architectures. Experience deploying machine learning models or building ML infrastructure. Background in data modeling, query optimization, and performance tuning. Exposure to Healthcare, AdTech, or privacy-sensitive data systems. Why Join BranchLab? Competitive salary (145-195k) + significant equity Tackle complex engineering challenges in privacy-first healthcare advertising. Work alongside top-tier engineers and data scientists. BranchLab