Senior Software Development 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

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.

Equal Employment Opportunity

BranchLab is an equal opportunity employer. We are committed to providing a workplace free from discrimination, harassment, and retaliation. Employment decisions are based on qualifications, merit, and business needs, without regard to race, color, religion, creed, national origin, ancestry, citizenship or immigration status, sex, pregnancy or related medical conditions, sexual orientation, gender identity or expression, age, disability, genetic information, marital, familial or caregiver status, military or veteran status, or any other characteristic protected by applicable law.