Senior CV Engineer

Joi AI is a platform for AI-lationships — personalized, emotionally intelligent connections between people and AI characters. We build characters that have their own personality, mood, and voice: they can ignore you, argue with you, miss you. If you've seen the film Her — that's roughly where we're headed.
Our platform serves both emotional and intimate needs without judgment, built on the values of rejection-free connection, sex positivity, freedom to be yourself, and ethical integrity. Today we have tens of millions of conversations on the platform. Our goal: 10% of the global population in long-term AI-lationships with our characters.
Joi Lab (joilab.ai) is our open research arm — we build open-source generative models, agent architectures, and training infrastructure. All code, weights, and data are public. We're not chasing the next ChatGPT wrapper; we're working on true AI agency: persistent memory, self-modification, self-authored constraints.
The role
We're looking for a Principal/Senior+ ML Engineer with deep expertise in Computer Vision and generative models. You'll own the CV direction end-to-end: from training diffusion models and designing architectures to building the validation pipeline and shaping the team roadmap.
This is a hands-on role. We move fast and expect you to go from idea to deployed result in days, not months.
WHAT YOU’LL DO
Train and fine-tune generative models (text2image, image2image, video2image, IP-adapters) to produce photorealistic and stylized visuals
Work with image classifiers, rankers, and image/video captioning models that understand visual context
Track cutting-edge CV research and open-source developments; translate them into a CV roadmap for the ML team
Build and own the iterative model improvement process, including quality validation systems for CV outputs
Optimize inference performance: diffusion optimization, quantization, kernel and framework-level work
Optionally: train multimodal AI companions that combine CV and NLP for deeper visual understanding
WHAT WE’RE LOOKING FOR
5+ Years of experience training diffusion models and modifying their architectures
Proficiency with diffusers and transformers libraries
Hands-on experience with IP-adapters
Backend engineering experience (Python, Go, C#) and knowledge of scalable deployment systems is an advantage
Nice to have:
Flow matching training
Diffusion model distillation
DPO and other text2image fine-tuning approaches
Text2video and CLIP fine-tuning
Experience with multimodal LLMs
NLP / LLM training and chatbot development background
WHY JOI
You're joining the company that's redefining what relationships with AI look like — before the category gets crowded
We move fast: ideas become live experiments in days, not quarters
Joi Lab gives you access to frontier model research — open-source, no corporate gatekeeping
Small team, high trust, high ownership — you'll see the direct impact of your work
Work from anywhere with our fully remote, full-time setup.
Standard 28-day annual leave policy.
7 yearly wellness days for life admin or recovery—no sick notes needed.
Referral rewards up to $5000 for helping us hire top talent.
We cover 50% of costs for training, conferences, and global meetups.
Subsidized English classes through our corporate discount.
Health support: receive up to $1,000 annually for medical fees or private insurance if you aren't on the group plan.
Optimized workspace: we equip you in-office or provide $1000 every three years to perfect your home office or co-working setup.
Peer-to-peer recognition: earn gratitude bonuses and swap them for swag, massage vouchers, or team adventures.
NEXT STEPS
Intro call — conversation with the Recruiter, includes a short live technical quiz (5 questions, camera on — no AI tools)
Technical interview — live coding session with AI tools allowed, plus ML and ML system design questions with CPO and CTO (90 min)
Joi AI is a platform for AI-lationships — personalized, emotionally intelligent connections between people and AI characters. We build characters that have their own personality, mood, and voice: they can ignore you, argue with you, miss you. If you've seen the film Her — that's roughly where we're headed.
Our platform serves both emotional and intimate needs without judgment, built on the values of rejection-free connection, sex positivity, freedom to be yourself, and ethical integrity. Today we have tens of millions of conversations on the platform. Our goal: 10% of the global population in long-term AI-lationships with our characters.
Joi Lab (joilab.ai) is our open research arm — we build open-source generative models, agent architectures, and training infrastructure. All code, weights, and data are public. We're not chasing the next ChatGPT wrapper; we're working on true AI agency: persistent memory, self-modification, self-authored constraints.
The role
We're looking for a Principal/Senior+ ML Engineer with deep expertise in Computer Vision and generative models. You'll own the CV direction end-to-end: from training diffusion models and designing architectures to building the validation pipeline and shaping the team roadmap.
This is a hands-on role. We move fast and expect you to go from idea to deployed result in days, not months.
WHAT YOU’LL DO
Train and fine-tune generative models (text2image, image2image, video2image, IP-adapters) to produce photorealistic and stylized visuals
Work with image classifiers, rankers, and image/video captioning models that understand visual context
Track cutting-edge CV research and open-source developments; translate them into a CV roadmap for the ML team
Build and own the iterative model improvement process, including quality validation systems for CV outputs
Optimize inference performance: diffusion optimization, quantization, kernel and framework-level work
Optionally: train multimodal AI companions that combine CV and NLP for deeper visual understanding
WHAT WE’RE LOOKING FOR
5+ Years of experience training diffusion models and modifying their architectures
Proficiency with diffusers and transformers libraries
Hands-on experience with IP-adapters
Backend engineering experience (Python, Go, C#) and knowledge of scalable deployment systems is an advantage
Nice to have:
Flow matching training
Diffusion model distillation
DPO and other text2image fine-tuning approaches
Text2video and CLIP fine-tuning
Experience with multimodal LLMs
NLP / LLM training and chatbot development background
WHY JOI
You're joining the company that's redefining what relationships with AI look like — before the category gets crowded
We move fast: ideas become live experiments in days, not quarters
Joi Lab gives you access to frontier model research — open-source, no corporate gatekeeping
Small team, high trust, high ownership — you'll see the direct impact of your work
Work from anywhere with our fully remote, full-time setup.
Standard 28-day annual leave policy.
7 yearly wellness days for life admin or recovery—no sick notes needed.
Referral rewards up to $5000 for helping us hire top talent.
We cover 50% of costs for training, conferences, and global meetups.
Subsidized English classes through our corporate discount.
Health support: receive up to $1,000 annually for medical fees or private insurance if you aren't on the group plan.
Optimized workspace: we equip you in-office or provide $1000 every three years to perfect your home office or co-working setup.
Peer-to-peer recognition: earn gratitude bonuses and swap them for swag, massage vouchers, or team adventures.
NEXT STEPS
Intro call — conversation with the Recruiter, includes a short live technical quiz (5 questions, camera on — no AI tools)
Technical interview — live coding session with AI tools allowed, plus ML and ML system design questions with CPO and CTO (90 min)
Joi AI is a platform for AI-lationships — personalized, emotionally intelligent connections between people and AI characters. We build characters that have their own personal