Principal Software Engineer, Backend

CMT is looking for a Principal Backend Software Engineer to produce scalable software solutions to reliably collect and manage data from sensors on smartphones and connected devices in vehicles. In this role, you will design architecture and backend infrastructure, and build features and applications that meet the needs of our customers. If you’re interested in using your skills to make the world's roads and drivers safer, we’d like to meet you. The person in this role will own the architecture and evolution of the backend systems that power DriveWell Fusion. You will design and scale high-throughput data pipelines, REST APIs, and real-time event processing systems that handle millions of device connections daily. You will partner with ML and Data Science teams to build the compute and data infrastructure that supports model training, feature engineering, and large-scale inference — including GPU-accelerated workloads. You will drive infrastructure-as-code practices, CI/CD reliability, and system observability to ensure our platform remains performant and resilient as we grow. As a technical leader, you will mentor engineers, set technical direction, and collaborate with product and engineering stakeholders to deliver solutions that keep tens of millions of drivers safe. 

CMT has helped protect over 65 million drivers and prevent over 126,000 crashes worldwide. We build AI to solve some of the most difficult challenges in mobility — understanding and reducing risk, detecting crashes, and getting people life-saving help. The problems are hard. The impact is real. No matter your role, your work will matter at CMT.

Responsibilities: 

• Participate throughout the planning process, collaborating with product managers, data scientists, and fellow engineers to balance technical feasibility with customer needs 
• Use independent judgment and discretion to implement and enhance solutions for telematics insights enabled by our processing pipelines 
• Identify and measure key production performance metrics, ensuring scalability and efficiency
• Design, implement, and maintain automated tests for telematics solutions, ensuring safe delivery of features and fixes 
• Ensure high bar for quality within our sphere of influence 
• Provide expert guidance on cloud software architecture 
• Keep the codebase healthy amidst increasing complexity 
• Mentor junior engineers as needed 
• Complete any additional tasks as they arise 

Qualifications: 

• Bachelor’s degree or equivalent years of experience and/or certification in Computer Science, Engineering, or related field 
• 7+ years of relevant professional experience 
• Proven experience with development at scale 
• Fluency in at least one programming language with ability to learn Python, Go, C++
• Experience with continuous deployment, and test-driven development (TDD) 
• Experience with relational database (RDBMS) schema design 
• Comfortable with AWS or similar services
• EC2, S3, Lambda, SNS, SQS, RDS (Postgres), Dynamo 
• Terraform, Terragrunt 
• Knowledgeable of containerization technologies (specifically Docker) 
• Ability to work independently when needed and to learn quickly

Nice to Haves: 

• Experience with large-scale cloud compute for ML inference, including GPU-accelerated infrastructure (e.g., EC2 GPU instances, SageMaker, EKS with GPU scheduling), GPU vs CPU workload allocation, model serving at scale, and trade-offs between batch and real-time inference 
• Experience building and operating data pipelines (ETL/ELT) at scale, and designing the data infrastructure that ML/Data Science teams rely on for feature engineering, model training, and production inference 
• Hands-on experience designing and operating high-throughput backend systems handling millions of API requests and device connections daily, including real-time data ingestion and event-driven architectures (message queues, streaming platforms) 
• Hands-on experience with containerization (Docker), container orchestration (AWS ECS or Kubernetes), and infrastructure-as-code using Terraform for managing cloud environments at scale
• Proficiency with observability and monitoring (Datadog, CloudWatch) including designing monitors, alerts, and SLOs 
• Strong knowledge in web security, session management, and experience with network diagnostics and analytics tools
• Experience using AI-assisted development tools (e.g., Claude Code, Cursor) as part of daily engineering workflows

Compensation and Benefits: 

• Fair and competitive salary based on skills and experience, and annual performance bonus 
• Equity may be awarded in the form of Restricted Stock Units (RSUs) 
• Medical, Dental, Vision and Life Insurance, matching 401k, short-term & long-term disability and parental leave 
• Unlimited Paid Time Off including vacation, sick days & public holidays 
• Flexible scheduling and work from home policy depending on role and responsibilities

Base Salary Range

• The base salary range for this position is: $167,200 to $209,000. This range is specifically for Cambridge, MA

Additional Perks:

• Work on a mission with real impact: crashes prevented, injuries avoided, lives protected around the world
• Join an industry leader — 65 million drivers protected, powering 140+ programs across 25 countries
• Recognized innovator in mobility AI, earning top honors including the TIME Industry Leader in AI, a Gold Edison Award, and the Artificial Intelligence Excellence Award for AI for Social Good. CMT is also Great Place to Work Certified
• Be part of the team inventing the future of mobility and road safety
• Move fast, own outcomes, do work that matters
• High ownership, small teams, and direct access to leadership — no layers between your work and its impact
• Unlimited PTO, flexible scheduling, competitive salary, annual performance bonus, RSUs, and full benefits including medical, dental, vision, and 401k match
• Summer Fridays provide team members with half days to recharge
• Join one of our employee resource groups: Black, AAPI, LGBTQIA+, Women, Book Club, and Health & Wellness
• Comprehensive wellness, education, and employee assistance programs

Commitment to Diversity and Inclusion:

At CMT, we believe the best ideas come from a mix of backgrounds and perspectives. 

We are an equal-opportunity employer committed to creating a workplace and culture where everyone feels valued, respected, and empowered to bring their unique talents and perspectives. Diversity is essential to our success, and we actively seek candidates from all backgrounds to join our growing team. 

We do not discriminate based on race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status or disability state. CMT is headquartered in Cambridge, MA. To learn more, visit www.cmtelematics.com and follow us on Instagram @cmt.ai

About Cambridge Mobile Telematics:

Cambridge Mobile Telematics (CMT) is the world’s largest telematics and AI company for safer mobility. Its mission is to make the world’s roads and drivers safer. The company’s AI-driven platform, DriveWell Fusion®, proactively identifies and reduces driving risk, leading to fewer crashes and injuries. To date, CMT’s technology has helped prevent over 126,000 crashes worldwide. CMT enables partners to measure risk, detect crashes, provide life-saving assistance, and streamline claims. Headquartered in Cambridge, MA, CMT operates globally with offices in Budapest, Hungary; Chennai, India; Seattle, Washington; Tokyo, Japan; and Zagreb, Croatia. Learn more at www.cmt.ai.