Principal Software Engineer, Full Stack

We are seeking an experienced Principal Software Engineer to lead complex projects, and mentor teams in building scalable and reliable full-stack solutions. The person in this role will play a pivotal role in shaping the technical direction of our platform and ensuring its continued success. CMT is looking for a Principal Software Engineer I, Full Stack to help us change the world. 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: Lead the development of critical features and components, ensuring high quality and timely delivery Provide technical guidance and mentorship to engineering teams, fostering a culture of excellence Identify and resolve complex technical challenges, proactively mitigating risks. Lead cross functional technical projects Evaluate and recommend new technologies and approaches to improve system performance and efficiency Design and implement robust, scalable, and maintainable architectures for complex systems Collaborate with product and engineering leaders to define technical roadmaps and strategies Anticipate future technical needs and ensure the platform is prepared for growth Contribute to the development of best practices and standards for software development Ensure the reliability and performance of production systems, providing on-call support as needed Drive continuous improvement initiatives to enhance operational efficiency Troubleshoot and resolve complex production issues, minimizing downtime Follow company defined development and operational standards and processes Mentor and guide senior and junior engineers, fostering their technical growth Lead code and design reviews, ensuring adherence to best practices Collaborate effectively with cross-functional teams, including product, QA, and operations Participate heavily in the hiring process, and improve the hiring process Complete any additional tasks as they arise Qualifications: Bachelor’s degree or equivalent years of experience and/or certification in a technical field 7+ years of relevant professional experience Deep expertise in web technologies (HTML, CSS, JavaScript, TypeScript) and modern web frameworks (e.g., React, Django) Extensive experience designing or developing Restful APIs or web services Strong proficiency in a backend development language (e.g. Python, Java) Expertise in cloud platforms (e.g., AWS), including services like EC2, S3, Lambda, SNS, SQS, RDS (Postgres), and NoSQL databases. Proven ability to design and implement scalable and resilient systems. Strong understanding of software development best practices, including testing, CI/CD, and DevOps Understanding of Agile development methodologies (specifically Scrum) Excellent communication and collaboration skills Customer obsessed, demonstrates initiative, has a learning mindset, takes ownership Demonstrated ability to drive technical initiatives and influence architectural decisions. Strong experience with system design 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 A dditional Perks: Work on a mission with real impact: crashes prevented, injuries avoided, lives protected around the world Join an industry leader — 65 million drivers pr