Senior Software Engineer

About the Role We're looking for a Senior Backend Engineer to join Third Loop’s development team to help build the foundational systems that power our product. You'll work closely with the founders and play a direct role in shaping our architecture, API design, and tech stack. This is a high-impact, high-ownership role. You'll move fast, make meaningful technical decisions, and see your work in production quickly. What Does Third Loop Do At Third Loop, we build engineering-grade AI/ML solutions for traditional engineers (mechanical, nuclear, chemical, etc.) that work in highly regulated industries. Our platform accelerates engineering tasks, codifies workflows, and transforms scattered knowledge bases into citable sources of truth. The heart of our product is human-in-the-loop design, privacy and security, and meeting the technical needs and rigor of our customers. What You'll Do Design, build, and maintain scalable backend services and REST APIs using Python and FastAPIArchitect and develop core platform infrastructure on AWS (Lambda, ECS, RDS, S3, SQS, etc.)Collaborate with frontend engineers and stakeholders to define contracts and data modelsWrite clean, well-tested, and well-documented code with a strong emphasis on reliabilityParticipate in code reviews, contribute to engineering standards, and help level up the teamContribute to infrastructure-as-code using tools like Terraform or AWS CDKProactively identify and address bottlenecks, technical debt, and security concernsOperate with autonomy; drive projects from design doc to deployment with minimal hand-holding What We're Looking ForRequired Minimum Education: Bachelor of Science in Computer Science, Software Engineering, Computer Engineering, or other related engineering discipline4+ years of professional backend software engineering experienceStrong proficiency in software development in one or more backend languages (Python, C#, Go, Java, etc.)Hands-on cloud experience: comfortable deploying and operating services in a cloud-native environmentSolid understanding of RESTful API design principles and best practicesExperience with both relational and non-relational databases (PostgreSQL, MongoDB)) and data modelingFamiliarity with CI/CD pipelines (GitHub Actions, CodePipeline, etc.)Strong written communication skills: you can write a clear design doc and a clear commit messageExperience with containerization (Docker, ECS, Kubernetes) Nice to Have Experience with document processing, NLP, or knowledge management systemsFamiliarity with event-driven architectures (SQS, SNS, Kafka)Prior experience at scaling software productsExposure to infrastructure-as-code (Terraform, AWS CDK, Pulumi)Experience in a startup environmentFamiliarity with React or TypeScript (enough to collaborate effectively with frontend engineers) What to Expect Ambiguity is the norm; you’ll help define problems, not just solve themSmall team means high ownership; you'll touch many layers of the stackDirect access to founders and stakeholders; minimal bureaucracy What Success Looks Like in the First 90 Days You ship multiple major features (3+) You become an owner/expert of a major component of the stack.You respond quickly to bugs and issues, helping set the standard of excellence. You make a product or technical decision that positively impacts the way the entire team works and ships code. What We Offer The salary range for this position is $150,000-$200,000 annually. Actual compensation is based on several factors including but not limited to experience, internal parity, education, and skills. Equity in the companyHybrid/Onsite preferred (DC/Northern VA), possible remote Health, dental, and vision benefitsThe opportunity to impact the engineering industry by building something from the ground up We ask a question about Voluntary Self-Identification of Veteran Status. The following is the complete context for the question: Voluntary Self-Identification of Veteran Status Why are you being asked to complete this form? 1. This employer is a Government contractor subject to the Vietnam Era Veterans' Readjustment Assistance Act of 1974, as amended by the Jobs for Veterans Act of 2002,38 U.S.C. 4212 (VEVRAA), which requires Government contractors to take affirmative action to employ and advance in employment: (1) disabled veterans; (2) recently separated veterans; (3) active duty wartime or campaign badge veterans; and (4) Armed Forces service medal veterans. These classifications are defined as follows: A "disabled veteran" is one of the following: A veteran of the U.S. military, ground, naval or air service who is entitled to compensation (or who but for the receipt of military retired pay would be entitled to compensation) under laws administered by the Secretary of Veterans Affairs; orA person who was discharged or released from active duty because of a service-connected disability. A "recently separated veteran" means any veteran during the three-year period beginning on the date of such veteran's discharge or release from active duty in the U.S. military, ground, naval, or air service. An "active duty wartime or campaign badge veteran" means a veteran who served on active duty in the U.S. military, ground, naval or air service during a war, or in a campaign or expedition for which a campaign badge has been authorized under the laws administered by the Department of Defense. An "Armed forces service medal veteran" means a veteran who, while serving on active duty in the U.S. military, ground, naval or air service, participated in a United States military operation for which an Armed Forces service medal was awarded pursuant to Executive Order 12985. Protected veterans may have additional rights under USERRA—the Uniformed Services Employment and Reemployment Rights Act. In particular, if you were absent from employment in order to perform service in the uniformed service, you may be entitled to be reemployed by your employer in the position you would have obtained with reasonable certainty if not for the absence due to service. For more information, call the U.S. Department of Labor's Veterans Employment and Training Service (VETS), toll-free, at 1-866-4-USA-DOL. 2. If you believe you belong to any of the categories of protected veterans listed above, please indicate by checking the appropriate box below. As a Government contractor subject to VEVRAA, we request this information in order to measure the effectiveness of the outreach and positive recruitment efforts we undertake pursuant to VEVRAA. 1) I IDENTIFY AS ONE OR MORE OF THE CLASSIFICATIONS OF PROTECTED VETERAN LISTED ABOVE 2) I AM NOT A PROTECTED VETERAN 3) I DON'T WISH TO ANSWER 3. Submission of this information is voluntary and refusal to provide it will not subject you to any adverse treatment. The information provided will be used only in ways that are not inconsistent with the Vietnam Era Veterans' Readjustment Assistance Act of 1974, as amended. 4. The information you submit will be kept confidential, except that (i) supervisors and managers may be informed regarding restrictions on the work or duties of disabled veterans, and regarding necessary accommodations; (ii) first aid and safety personnel may be informed, when and to the extent appropriate, if you have a condition that might require emergency treatment; and (iii) Government officials engaged in enforcing laws administered by the Office of Federal Contract Compliance Programs, or enforcing the Americans with Disabilities Act, may be informed.