Back to jobs

ML Researcher - Posttraining

San Francisco · San Francisco, California, United States

Live, first seen by us 60 days ago
Pay
Pay not listedSimilar roles state $166K–$240K
Work setting
On-site — work setting source
Location type: On-site
From the employer’s posting
Employment
Full-time — employment source
Employment type: Full-time
From the employer’s posting
Team
Research — team source
Department: Research
From the employer’s posting

Before you apply

Work authorization
Sponsors visas

What you’ll work on

Full posting
  • Finetune diffusion models at scale to improve image aesthetics and quality

  • Implement posttraining techniques such as SFT, preference optimization, RL, and distillation

  • Design eval suites and reward designs for the image-space RL stage

  • Train custom VLM reward models and LLMs for prompt expansion

  • Coordinate with data teams and partners on preference data and evaluation results

From the employer’s posting
Finetune diffusion models at scale to improve image aesthetics and quality.
Implement posttraining techniques ranging from supervised finetuning, preference optimization, reinforcement learning, on-policy distillation, and various distillation / acceleration techniques.
Design comprehensive eval suites and reward designs for the reinforcement learning stage focused on image space.
Train custom VLM as reward models as part of our reward design. Train custom LLMs for prompt expansion through finetuning and reinforcement learning.
Coordinate with data teams and partners to manage collection of preference data and model evaluation results.

Benefits in the posting

Full benefits wording
  • Health & wellness: 100% health & 99% dental/vision insurance premiums covered for employees, health FSA accounts, & long-term disability coverage
  • Time off: Flexible PTO policy
  • Financial planning: 401k with a 4% company-sponsored match
  • Please note the above benefits & perks are for full-time employees

From the employer’s posting.

About Krea

We're dedicated to making AI intuitive and controllable for creatives - our mission is to build tools that empower human creativity, not replace it.

In the employer’s words · Read in context · Company website ↗

Apply at Krea

Posting record

Report an error
Status in our records
Live
First seen by us
Sep 5, 202660 days ago
Recorded sightings
43
Last seen by us
Nov 4, 2026
Employer says posted
Sep 1, 2026

These dates show when we found the posting. Check the employer’s website to confirm it is still accepting applications.

How this job compares

Pay

$166K–$240K is typical

The middle half of what similar US postings state. This one doesn’t list pay.

From 1,279 postings in the last year. Stated ranges, not salaries paid.

Time since we first saw it

Day 60

Similar jobs usually come down between day 6 and day 69.

From 4,296 similar postings that came down. Coming down is not always a hire.

Krea is hiring

4 open jobs

Open jobs by the week we first saw them, last 12 weeks.

Hiring record

See how this role fits your experience

Add your resume and we’ll mark which of these tools you already use, and point out anything in the posting that could rule you out.

  • PyTorch
Where the posting names them
- Strong understanding of both LLM and diffusion post training pipelines and algorithms such as PPO, GRPO, DPO, OPD, and MOPD. - Strong proficiency in PyTorch and understanding of its inner workings. - Strong background in distributed training paradigms such as FSDP, CP, SP, USP, TP, and EP. Knowing how different parallelism strategies work together and their tradeoffs.

Your next step

Complete your application on jobs.ashbyhq.com. The employer’s form will show what is required.

Applying through Ashby

  • No account needed. “Autofill from resume” at the top of the form fills the key fields from your file.

Already applied? Track this application

About the role

We file this job under ML Engineer, by the work the posting describes.

ML engineers put machine learning models into products. They write the code that trains, ships, serves and monitors models so a recommendation or prediction works for real users.

Postings ask for strong Python and software engineering, a framework such as PyTorch, cloud services, and more and more often experience with large language models.

A data scientist often works out which model to build; an ML engineer makes it run reliably in production.

US government figures for computer and information research scientists

Median yearly pay, May 2025
$140,300
Expected change, 2025 to 2035
21.8% more jobsagainst 3.5% for all jobs

The government has no code for ML engineers, so these figures are for the closest group, computer and information research scientists.

Source: US Bureau of Labor Statistics, Occupational Employment and Wage Statistics (May 2025) and Employment Projections (2025 to 2035). Occupation code 15-1221.

Job description

View original posting ↗

About Krea

At Krea, we are building next-generation AI creative tools.

We're dedicated to making AI intuitive and controllable for creatives - our mission is to build tools that empower human creativity, not replace it. We believe AI is a new medium that allows us to express ourselves through various formats - text, images, video, sound, and even 3D. We're building better, smarter, and more controllable tools to harness this medium. We recently took this a step forward with the launch of Krea 2, our first foundation model, built completely from scratch for aesthetic diversity and stylistic control, and with Krea 3 - our new image editing model.

We've raised over $83M and are backed by world-class investors such as a16z, Bain Capital, and Abstract. We work full-time and in-person at our waterfront office in San Francisco. We care about creativity: our team includes musicians, designers, visual artists, and engineers.

 

We're looking for someone with deep experience in large-scale finetuning of diffusion models and posttraining techniques. We have loads of high-quality data and aim to enhance the quality and aesthetics of the models we're building.

Our culture

  • We work full-time and in-person at our North Beach office in San Francisco.

  • We believe that demonstrated interest in the creative space is key: our team includes musicians, designers, visual artists and more.

  • Fast iteration and execution speed. Bias towards action, agency, and independence.

What you'll do

  • Finetune diffusion models at scale to improve image aesthetics and quality.

  • Implement posttraining techniques ranging from supervised finetuning, preference optimization, reinforcement learning, on-policy distillation, and various distillation / acceleration techniques.

  • Design comprehensive eval suites and reward designs for the reinforcement learning stage focused on image space.

  • Train custom VLM as reward models as part of our reward design.

  • Train custom LLMs for prompt expansion through finetuning and reinforcement learning.

  • Coordinate with data teams and partners to manage collection of preference data and model evaluation results.

  • Work on safety alignment of our models for open source release.

  • Collaborate with our AI research and engineering teams to integrate advancements into our products.


What we're looking for

  • Proven work of posttraining diffusion models for image or video generation.

  • Experience with large-scale model training, inference, and optimization.

  • Strong understanding of both LLM and diffusion post training pipelines and algorithms such as PPO, GRPO, DPO, OPD, and MOPD.

  • Strong proficiency in PyTorch and understanding of its inner workings.

  • Strong background in distributed training paradigms such as FSDP, CP, SP, USP, TP, and EP. Knowing how different parallelism strategies work together and their tradeoffs.

  • Good knowledge of low precision training / inference in FP8, NVFP4, and MXFP8.

  • Good understanding of algorithms and techniques used in fast inference engines such as vLLM and sglang as well as existing RL frameworks in LLM space such as slime, miles, tinker, and verl.

  • Understanding of various RL infrastructure and optimization techniques such as async RL, fast weight transfer, pipelining rollouts, managing off policy data.

  • Ability to monitor model regression and identify weak areas and turn them into concrete evals and reward design.

  • Experience training VLM models. Many of our custom reward models use VLM to provide reward signals for our models.

  • Keeping up with the developments in related fields such as LLM, VLM, representation learning, and robotics research.

  • Being comfortable working in a goal-oriented research environment.

  • Having good judgement around when one should explore different training strategies and when it's time to commit to a specific strategy to scale compute and data.

  • Comfortable working with underspecified goals. We expect every technical member to take an ambiguous research goal and break it down into concrete requirements, plans, experiment plan, and execution items.

  • Good research taste — bias towards simplicity and methods that scale well with compute, data, and minimal human supervision.

What we offer

  • Team: Work alongside a world-class team building the future of AI creative tooling

  • Impact: Significant scope and company-wide impact

  • Competitive compensation: generous salary & equity packages

  • Health & wellness: 100% health & 99% dental/vision insurance premiums covered for employees, health FSA accounts, & long-term disability coverage

  • Time off: Flexible PTO policy

  • Financial planning: 401k with a 4% company-sponsored match

  • Meals in the office: breakfast, lunch, dinner - you name it, we'll cover it

  • Transit: Ubers covered to & from the office

  • Sponsorship: We're open to sponsoring international visas where we can (e.g., STEM OPT, OPT, H-1B, O-1, E-3).

  • And more!

Please note the above benefits & perks are for full-time employees

Source details

View original posting ↗

Source notes

Source excerpts

Selected passages from the saved posting. Check the full description for conditions and exceptions.

Pay

No pay amount identified in the saved description.

Location & working pattern

San Francisco, California, United States

Working pattern and location restrictions need checking in the full posting.

Work authorization
- Transit: Ubers covered to & from the office - Sponsorship: We're open to sponsoring international visas where we can (e.g., STEM OPT, OPT, H-1B, O-1, E-3). - And more!

Find answers in the posting

AI
How answers work

AI selects complete passages from this posting. Check them for conditions and exceptions.

Uses this posting and your question. No profile needed.