Job DescriptionJob DescriptionCaptions is the leading video AI company, building the future of video creation. Over 10 million creators and businesses have used Captions to create videos for social media, marketing, sales, and more. We're on a mission to serve the next billion. We are a rapidly growing team of ambitious, experienced, and devoted engineers, researchers, designers, marketers, and operators based in NYC. You'll join an early team and have an outsized impact on the product and the company's culture.We’re very fortunate to have some the best investors and entrepreneurs backing us, including Index Ventures (Series C lead), Kleiner Perkins (Series B lead), Sequoia Capital (Series A and Seed co-lead), Andreessen Horowitz (Series A and Seed co-lead), Uncommon Projects, Kevin Systrom, Mike Krieger, Lenny Rachitsky, Antoine Martin, Julie Zhuo, Ben Rubin, Jaren Glover, SVAngel, 20VC, Ludlow Ventures, Chapter One, and more. Check out our latest financing milestone and some other coverage: The Information: 50 Most Promising StartupsFast Company: Next Big Things in TechThe New York Times: When A.I. Bridged a Language Gap, They Fell in LoveBusiness Insider: 34 most promising AI startupsTime: The Best Inventions of 2024** Please note that all of our roles will require you to be in-person at our NYC HQ (located in Union Square) We do not work with third-party recruiting agencies, please do not contact us** About the roleOur software engineers work across the stack to build consumer-facing products for millions of creators and businesses worldwide, and we’re currently hiring experienced full-stack engineers to join our web-platform team. Our product engineers push the limits of what’s possible in the browser—from custom graphics rendering to sophisticated video processing, and the integration of large video-generation models—tackling complex engineering and product challenges to enable creators to tell their stories with audio, video, and beyond.Key ResponsibilitiesBuild user-centric products by leveraging modern frontend, backend, and API technologies, including advanced in-browser rendering (e.g., WebAssembly & WebGL).Implement full-stack solutions that balance performance, scalability, reliability, and extensibility. Own the product development lifecycle alongside cross-functional teammates (product, design, infra, and ML) to shape features from early concepts through final release.Maintain a high bar for code quality by championing best practices, testing, and participating in thoughtful code reviews.Preferred Qualifications7+ years of professional software engineering experienceStrong understanding of Computer Science fundamentals (algorithms and data structures).Proficiency in full-stack software development, including modern front-end technologies, back-end technologies, API frameworks, and cloud platforms. Bonus points for experience with complex rendering or real-time media processingBenefits:Comprehensive medical, dental, and vision plans401K with employer matchCommuter BenefitsCatered lunch multiple days per weekDinner stipend every night if you're working late and want a bite! Doordash DashPass subscriptionHealth & Wellness Perks (Talkspace, Kindbody, One Medical subscription, HealthAdvocate, Teladoc)Multiple team offsites per year with team events every monthGenerous PTO policyCaptions provides equal employment opportunities to all employees and applicants for employment and prohibits discrimination and harassment of any type without regard to race, color, religion, age, sex, national origin, disability status, genetics, protected veteran status, sexual orientation, gender identity or expression, or any other characteristic protected by federal, state or local laws.Please note benefits apply to full time employees only.Compensation Range: $170K - $250K
Job DescriptionJob DescriptionCaptions is the leading video AI company, building the future of video creation. Over 10 million creators and businesses have used Captions to create videos for social media, marketing, sales, and more. We're on a mission to serve the next billion. We are a rapidly growing team of ambitious, experienced, and devoted engineers, researchers, designers, marketers, and operators based in NYC. You'll join an early team and have an outsized impact on the product and the company's culture.We’re very fortunate to have some the best investors and entrepreneurs backing us, including Index Ventures (Series C lead), Kleiner Perkins (Series B lead), Sequoia Capital (Series A and Seed co-lead), Andreessen Horowitz (Series A and Seed co-lead), Uncommon Projects, Kevin Systrom, Mike Krieger, Lenny Rachitsky, Antoine Martin, Julie Zhuo, Ben Rubin, Jaren Glover, SVAngel, 20VC, Ludlow Ventures, Chapter One, and more. Check out our latest financing milestone and some other coverage: The Information: 50 Most Promising StartupsFast Company: Next Big Things in TechThe New York Times: When A.I. Bridged a Language Gap, They Fell in LoveBusiness Insider: 34 most promising AI startupsTime: The Best Inventions of 2024** Please note that all of our roles will require you to be in-person at our NYC HQ (located in Union Square) We do not work with third-party recruiting agencies, please do not contact us** About the role:Captions seeks an exceptional MLOps Research Engineer (MOTS) to architect and scale the machine learning infrastructure for our rapidly growing creative platform used by millions. You'll own the development of our distributed training systems, optimize our rapidly growing GPU clusters, and build performant inference pipelines that power our cutting-edge multimodal video diffusion models. As a key member of our ML Research team in a fast-growing Series C startup, you'll create foundational infrastructure enabling rapid research iteration while maintaining production-grade reliability and efficiency. We're already training large-scale models and are excited to dramatically expand our infrastructure capabilities.Key Responsibilities:Core Systems Development:Develop and optimize distributed training frameworks integrating multiple modalities (video, audio, text, and structured metadata)Build flexible systems for cross-modal training orchestration and efficient experimentationDesign reproducible training environments with versioned dependencies and configurationsImplement comprehensive testing frameworks for validating model training correctness and performanceCreate infrastructure for systematic model quality assessment and performance benchmarkingInfrastructure Development:Design and implement flexible training orchestration systems that balance research agility with large-scale model trainingBuild robust monitoring and observability systems for complex training and inference pipelinesDesign and manage GPU clusters optimized for distributed training of multimodal modelsBuild out comprehensive automated metrics collection and alerting across our ML stackSystem Optimization:Profile and optimize model training throughput using mixed precision, gradient checkpointing, and advanced memory techniquesDevelop custom CUDA and Triton kernels to accelerate critical compute pathsImplement creative solutions for cost optimization across spot instances and reserved capacityDesign and optimize real-time inference systems enabling fast research iteration cyclesResearch & Product Impact:Build infrastructure enabling rapid testing of research hypothesesCreate systems supporting close collaboration between infrastructure and research teamsDevelop frameworks for reproducible research experimentationEnable seamless deployment of research innovations to productionRequirements:Technical Background:Bachelor's or Master's degree in Computer Science, Machine Learning, or related fieldStrong programming skills in Python and systems programmingExperience with distributed systems and scalable infrastructureTrack record of building reliable, performant large-scale ML systemsAreas of Expertise (Strong experience in some or all of these areas):Deep expertise in PyTorch internals and distributed training frameworks (FSDP, DeepSpeed)GPU cluster management and optimizationPerformance profiling and systems optimizationCUDA programming and kernel optimizationContainerization and orchestration (Docker, Kubernetes)ML model serving and deployment at scaleLanguage models and attention mechanism optimizationVideo and audio processing pipelinesLarge-scale diffusion modelsEngineering Approach:Love diving deep into complex systems optimization challengesTake ownership of critical infrastructure while collaborating effectivelyGet excited about pushing the boundaries of ML system performanceWant to work directly with researchers on cutting-edge ML problemsThrive in fast-paced, research-driven environmentsAbout the Team:You'll work full-time, on-site in our NYC office alongside researchers and engineers who are dedicated to building world-class generative models and data infrastructures. We've intentionally built a culture that prizes open discussion of technical approaches, rapid iteration, and direct access to decision makers. Your success will be measured by the performance and reliability of our systems, enabling our researchers to iterate quickly on and develop ambitious ideas. You'll have significant autonomy to shape our infrastructure direction and direct impact on our ability to serve millions of creators.Our team values:Open technical discussions and collaborationRapid iteration and practical solutionsDeep technical expertise and continuous learningDirect impact on research and product outcomesBenefits:Comprehensive medical, dental, and vision plans401K with employer matchCommuter BenefitsCatered lunch multiple days per weekDinner stipend every night if you're working late and want a bite! Doordash DashPass subscriptionHealth & Wellness Perks (Talkspace, Kindbody, One Medical subscription, HealthAdvocate, Teladoc)Multiple team offsites per year with team events every monthGenerous PTO policyCaptions provides equal employment opportunities to all employees and applicants for employment and prohibits discrimination and harassment of any type without regard to race, color, religion, age, sex, national origin, disability status, genetics, protected veteran status, sexual orientation, gender identity or expression, or any other characteristic protected by federal, state or local laws.Please note benefits apply to full time employees only.Compensation Range: $160K - $250K
