Hi HN! I’m Antoine, Head of Research at Castle. We’re a YC-backed Series A startup helping companies like Canva, Atlassian, and Rockstar Games fight fraud and abuse. We're building modern, AI-powered bot detection and abuse prevention tech, with a focus on real-time protection and behavioral intelligence. We’re a small, fast-moving team looking to add two technical roles:

Senior ML Engineer – Fraud & Bot Detection You'll work on real-time ML pipelines, anomaly detection, and adversarial ML techniques to stop bots and malicious actors. We’re combining traditional fraud signals with modern AI—LLMs, behavioral clustering, and vector-based search—to stay ahead of attackers. You’ll own models end to end and deploy quickly, with direct access to rich, structured behavioral and fingerprinting data. Ideal for someone with strong experience in the anti-fraud/anti-bot field who loves cutting-edge ML and wants immediate impact.

Senior Detection Engine Engineer (R&D) You’ll build and scale the core infrastructure behind our detection logic—rule engines, fingerprinting pipelines, and high-speed signal ingestion. We’re integrating AI-driven detection and auto-adaptive logic that reacts in real time. If you enjoy real-time systems, security, and automation, this is a highly technical role that’s at the core of our detection stack. Perfect if you’ve worked in security, data pipelines, or real-time analytics and want to outsmart fraudsters.

We pay US salaries globally | Fully remote from Europe/EMEA timezone | Flexible hours | Unlimited PTO | Paid parental leave We're actively hiring and committed to responding to every qualified applicant.

Drop us a line: antoine.vastel@castle.io

We’re building novel robots for case picking in warehouses, a huge unsolved automation opportunity for a very labor-intensive, critically important and sh*tty human job in the thin-margin industry of logistics. Our software is all Rust/Pytorch, embedded dev through research-frontier applied algorithms and an integrated development iteration time measured on a watch, not a calendar.

There’s more than enough fun problems to go around, and we’re looking to grow the team with a couple more great-to-work-with folks, including generalists or job descriptions we haven’t realized we should be hiring for. We’re also specifically looking for a summer applied ML intern for robotic perception and controls. There’s a lot more cool stuff we can’t share publicly just yet. To apply, email a resume to <the-two-letters-of-this-site>@autopallet.bot, and include the role you’re looking for in the subject line, and we’ll take it from there. Bonus points if you include a link or photo of something cool you’ve made.

Jurisphere is currently the leading AI copilot for lawyers in India, and we are planning to rapidly expand to the global market. You will be part of the growth journey where you will lead a team of engineers and ship rapidly to make a product that can beat the likes of Harvey.

Our requirements are the following

- 2-5 years of experience with Python, FastAPI, NextJS, TypeScript, Docker, Kubernetes, cloud platforms, CI-CD, observability, scaling etc.

- Familiarity with AI and LLM engineering would be a plus, but not a complete deal breaker.

- Familiarity with large scale data pipelines, ETL systems, search solutions would be a great plus.

- Being self-oriented and the drive to make an impact is non-negotiable. Along that line, having your own projects or past entrepreneurship experience would be highly valued.

Please reach out to sumit@jurisphere.ai with your resume and an introduction if you are interested and would be a good fit for this role.

Compensation range: 25-50 lakhs INR per annum along with generous equity offering.

TensorZero creates a feedback loop for optimizing LLM applications — turning production data into smarter, faster, and cheaper models.

We're looking for a Founding Member of Technical Staff with any of the following skillsets:

‣ Back-end / Systems Engineering (Rust)

‣ Front-end / Design Engineering (React)

‣ ML Engineering / Research (Python)

What we offer:

‣ Vast majority of your work → open source

‣ Years of runway

‣ Small and entirely technical team: former Rust compiler maintainer, ML researchers with 1000's of citations, decacorn CPO

‣ $200-250k base + up to 1% equity + benefits

‣ Onsite (5 days) in NYC

More information: https://tensorzero.com/candidate-brief

Apply: https://www.tensorzero.com/jobs

We’re seeking our first engineering hire (full-stack) at ModernVivo (https://www.modernvivo.com). We’re building literature review and study design tooling for life sciences researchers in the in vivo space. Our core software elucidates study design insights from scientific documents to reduce inefficient animal use, accelerate preclinical development timelines, and improve the probabilities of success for drug discovery.

Only hard requirements are proficiency in TypeScript/React and Python. Strong preference for proficiency in Django, experience with UI/UX design, and for candidates to be based in Seattle (although we are remote-friendly). We’re generally not looking for new graduates except for those with exceptional experience.

Please reach out to colin@modernvivo.com with either your resume or the resume/introduction for a candidate you can vouch for!

We are a rapidly growing, institutionally funded company at the forefront of the fastest growing‬ segment in the automotive industry. Our cutting-edge service is transforming the collision‬ center industry, and our innovative software is vital to our success. The engineering team builds‬‭ systems that deliver exceptional user experiences and drive value for our customers. We are‬ committed to creating impactful software solutions while fostering a collaborative and inclusive‬ work environment.‬ ‭ We are seeking an experienced Software Engineer to join our team. Our multi-tenant‬ architecture includes React with Typescript backed by Node and PostgreSQL and is deployed to‬ Google Cloud Platform using git actions and Terraform. Background data wrangling often‬ involves Python and BigQuery.‬

This role is ideal for someone who can contribute across frontend code, backend systems and‬ deployment infrastructure. This is someone who has built and supported substantial software‬ products. You will design, develop, and deploy high-quality software while driving architectural‬ decisions and mentoring other developers. Your expertise will help shape the future of our‬ technology stack and applications.

Please reach out to us at eng-hire@adas-safe.com‬‭ for any inquiries or questions about‬ this position.‬

Heavily focused on hiring sr/staff/principal backend, data infra, or MLE's at this time

Profiles of our team members: https://www.linkedin.com/company/layerhealth/people/

Recent article on our Series A round raise: https://www.mobihealthnews.com/news/layer-health-garners-21m...

Layer Health is an AI/ML startup (fresh Series A) leveraging LLM’s to transform how clinical data is understood and used. We’re tackling a huge inefficiency in healthcare—patient chart abstraction, a $2B/year problem. Today, nurses handle it manually, drowning in notes and reports instead of focusing on patient care. Chart abstraction represents the largest source of labeled data in healthcare; an ML/researcher’s dream for answering complex clinical questions (which his why much of our team has a deeply focused research/ML background).

Work Locations: Boston /Back Bay (beautiful office overlooking Boston Common) or NYC (Grand Central area). No remote work

Headcount: ~18; likely 40-50 by end of year

Stack: mostly React + Typescript Frontend / Python Backend // GCP (though we are not hiring frontend at this time)

Open Roles: Sr/Staff/Principal Backend/MLE/Data Architecture/Infra (1-2 roles each)* ML Research Engineering * Research Scientist (PhD's) * Head of Product * Product Designer

Email at mike-c@layerhealth.com for more info

Atomic Tessellator is building the world's fastest, most comprehensive materials design web platform. We're giving materials scientists the ability to create and test different permutations of atomic structures, and evaluate every known material property, with preconfigured computing environments.

We're seeking a front end developer with Three.js experience to lead our platform UI development (Vue.js). You'll also be solving the technical challenge of rendering complex atomistic simulations in a physically accurate, visually interpretable, and performant way.

We're a tight, global team of 5 with a hacker mentality. We're AI-native, value taste, have audacious goals, and move at unreal speeds. We take pride in being generalists.

Interested or have questions? Please send through your CV to daniel+cvs@atomictessellator.com :)

More Optimal provides a low-code environment specifically aimed at Operations Researchers who use our platform to solve the most difficult planning and optimization challenges in the world. For our R&D department we are looking for an R&D engineer who is enthusiastic about working on a complex system, solving puzzles and loves complex programming challenges, to make More Optimal even more loved by our customers as well as implementation partners.

In our R&D team you will be able to work on a very diverse combination of problems depending on your preferences: frontend, backend, advanced algorithms and infrastructure. We are a fast-growing company where you can make a real impact quickly.

Tech stack: TS/JS (primarily), Java/Kotlin, Python, Go, GCP

Feel free to contact me directly (timo@moreoptimal.com) if you have any questions about the job opening.

Cactus is a strategy, design, and engineering firm that builds physical and digital products for some of the world's leading healthcare clinics. Fully remote with teams based in the US and Brazil, we're hiring for a variety of software engineering roles (https://www.cactus.is/careers).

- Backend and Fullstack: Python and JS, SQL/PostgreSQL and NoSQL tools (GCP experience a plus)

- iOS and Android: Swift and Kotlin/Java

- Frontend: React, JS, and a variety of data viz and interactive libraries

- Engineering Managers: to lead our client projects and teams

Email careers@cactus.is with your name, github/code samples, and resume or LinkedIn. It's a plus but not required to have past experience working with healthcare tools and standards like EMRs, HIEs, HIPAA, FHIR, interoperability, etc.