Rappo | https://buildrappo.com | Founding Applied AI Engineer | Remote or Onsite SF

Hi, we have been working on a personal assistant for knowledge professionals. A lot of challenges around building an advanced RAG, improving reasoning, and custom models

Learn more about the role: https://wellfound.com/jobs/3382533-senior-ai-ml-engineer or email Email is hidden

PS: I am a solo founder, and we are generous with equity

Y Combinator (yes, the people who run this site) | Full stack web and AI | San Francisco | Onsite | Fulltime

YC itself hires software engineers from time to time. Many people don't know that YC has a small but very important software team. We run several websites - not just this one, but also workatastartup.com (the main way YC companies hire), a social network for YC founders, and the core infrastructure that YC itself runs on.

Recently, we've been spending most of our time building our own AI agents. Over the last year, YC has mostly funded AI agent companies, so it's been cool to go really deep building our own AI agents too. We're building agents to automate every aspect of what we do, and pushing the limits of what's possible with the current models to do it.

An unusual aspect of being on the YC software team is that you'll get full access to the YC program, founders and partners. The YC batch runs in the same building we work out of, so there are talks with famous founders happening most nights, right downstairs in our building. If you want to start a startup someday, working at YC would be an excellent jumping off point - several YC companies have come from team members who decided to start their own company.

YC works fully in-person in SF. We're happy to help you move here if you're in the US already. Unfortunately we can't sponsor new visas, but we're happy to transfer existing ones.

YC offers highly competitive compensation and benefits.

You can apply online (https://www.ycombinator.com/careers) or just email me at Email is hidden

We are LIFEPOWR! Antwerp (Belgium) | Full-time | Remote (Europe) or hybrid (Antwerp) | https://www.lifepowr.io/en/about-us/career

A young and dynamic company, active in energy transition and scaling up!

We are looking for a OPS Application & AI Developer

Your role will be:

-Customizing and maintaining our ERP platform hosted on Odoo.sh

-Developing custom modules, integrating third-party tools, optimizing workflows

-Supporting our internal teams with technical solutions

Send your back-end development expertise and your understanding of Odoo.sh!

Make sure to send your resume, GitHub profile (if available), and examples of past Odoo customizations to Email is hidden, including “OPS Application & AI Developer - Hacker news” in the subject line.

Undetect.io | Counter-Security / Reverse Engineer | Full Time / Part Time | Remote, Global

We're looking for a TypeScript engineer to join our team with a tight focus on stealth browser automation tools and RE / adversary intelligence pipelines.

You should have:

• Strong TypeScript, Node.js, CDP (Chrome Devtools Protocol) experience.

• Interest in C++ and Chromium internals.

• Experience evading or analyzing anti-bot and WAF systems.

• Practical experience reverse engineering & deobfuscation of heavily obfuscated / defended JavaScript.

• Intermediate / advanced understanding of browser fingerprinting and distributed proxy systems (or eagerness to learn).

• Able to provide examples of clean, maintainable code.

• Familiarity with Docker, Cloudflare Workers, and basic devops.

We're a lean, fast-moving team working on hard problems with real-world impact for enterprise clients, including many Y-Combinator success stories.

Email us: Email is hidden

Kaedim | Software Engineer, Machine Learning Engineer, Customer Support Engineer, Product Manager, Founding Recruiter | Onsite | Full-time | San Francisco, Singapore, London | US & UK Sponsorship Available Kaedim is an AI startup building ML algorithms that turn images into digital 3d models. We are a group of ~10 looking to grow the team to help streamline 3d content creation for 3d artists and are already working with 1 of the top 10 games of all time! Using our AI and in-house art team, we have the most accurate, game-ready 2d → 3d asset generation pipeline. Currently, we are offering a 10x speed up to 3D asset creation pipelines of 200+ game developers and we are working with partners like Voodoo, Upland, Azra Games. Check out our demo here: https://www.youtube.com/watch?v=tlqwfg1dlb0

Job descriptions and application link: https://join-kaedim.notion.site/

Tech Stack:

Product (web app, API): React, MySQL, NodeJS, Python, AWS

Machine Learning: Python, PyTorch, AWS

CredCore | Engineering | Full-time | US/India | www.credcore.com

CredCore helps companies analyze Credit Agreements using AI. We are looking to hire an Engineering Lead with 10+ years of experience. You should be familiar with design patterns and software architecture, infra/kubernetes, and TypeScript/Python. If you’re interested, please reach out to us at Email is hidden.

A cover letter is not necessary. But please share your resume and links to your GitHub/GitLab/StackOverflow/other profile, or blog/papers, or other portfolio we can review before setting up the interviews.

fleming.de | Full Stack Engineer | Magdeburg, Berlin, Hybrid (Germany) | Full Time | German required

Fleming (www.fleming.de) is digitalizing financing for health professionals. We are building and maintaining a React-Native / Nestjs based bank account frontend and a Salesforce base loan sales platform with a Ruby on Rails frontend. We are looking for a well-rounded engineer. You don't have to know the technologies we are using if you bring the conceptual knowledge and the drive to learn.

Some German language knowledge is required since you are going to build German UIs

more info: https://fleming.de/jobs/

Contact Email is hidden

Moyai | Amsterdam, The Netherlands | Full Time | Onsite | Founding AI Engineer | 60k-80k + Equity

About the company:

• Technical founding team with relevant industry experience (part of Nvidia Inception Program)

• Backed by well-known European VCs (SpeedInvest+Galion.exe)

• Building agentic advanced analytics and fine-tuning analytical reasoning models

Ideal candidate:

• Demonstrated shipping ability with past projects & roles

• "Young and hungry” mindset, prioritising ability to learn with agency over experience

• Familiar with fine-tuning algorithms and frameworks, transformers/trl, ART, verl and unsloth

• Bonus points for experience in contributing to open-source projects, startups, AI agents, & similar technologies

Reach out to the founder directly: https://www.linkedin.com/in/rhommes/

ELI Beamlines (ELI ERIC) | Dolní Břežany (Prague), Czech Republic | Onsite (with HO) | Full‑time

We operate one of the world’s leading high‑power laser research facilities (up to 10 PW) and support an international user community. We’re hiring:

• Director for Technology Lead the Technology Division (laser beam transport, instrumentation, engineering services, control systems, data infrastructure). Set the technical roadmap, grow teams, and ensure reliability and integration across the facility. Apply: https://www.eli-beams.eu/careers/director-for-technology/

• SW Control Systems Developer Join the Controls Hardware Integration team. Build and maintain device control & data‑acquisition for lasers/beamlines (EPICS). Write IOCs/services in C/C++/Python, integrate hardware, and collaborate with scientists on Linux. Apply: https://www.eli-beams.eu/careers/sw-control-systems-develope...

• Web Developer for Data Visualization Build interactive tools and UIs that help researchers visualize experiment data and plan setups (from dashboards to 3D/WebGL). Work across Python backends & modern JS frontends; design clean APIs; familiarity with Jupyter/three.js/D3 a plus. Apply: https://www.eli-beams.eu/careers/web-developer-for-data-visu...

• Safety Systems Engineer (PLC / Interlocks) Own the PLC‑based Personal Safety Interlock (PSI): define state logic, supervise installation/upgrades with suppliers, commission new areas, and keep documentation, testing and availability tight. Apply: https://www.eli-beams.eu/careers/safety-systems-engineer-152...

How we hire: CV → HR pre‑screen → interviews (in‑person or Webex). Questions? Email HR: Email is hidden Or me with technical ones Email is hidden

About us: ~350 people from 38+ countries; easy public‑transport commute from Prague. Keywords: EPICS, Python, Linux, PLC/Safety, JavaScript/TypeScript, Git.

ShieldAI | Web & Infrastructure Engineer | Full-time | Remote (US) or San Diego, CA with occasional travel

ShieldAI's Hivemind Special Project is hiring a Staff to Principal-level Infrastructure & Web Applications Engineer. We're a small team entirely comprised of L5-L8 ICs, working to bring seamless robotic behavior and coordination development from a sci-fi concept into reality. Our team work on a collection of long-term initiatives, demos, spike/proof of concepts, and assists to support Hivemind Product and Hivemind Solutions. LLM/AI applications for development acceleration represent a significant portion of our focus.

For this role, we are looking for someone deeply versed into Web Application and Infrastructure development. In particular TypeScript, bundlers, isomorphic development strategies, Web semantics, CSS/modules, browser performance optimization, protocols etc. If you have built custom webpack loaders, an SSR framework of FRP renderer from scratch, done packet level processing, or frame-rate optimizations in React, and have strong opinions about functional development and infrastructure please reach out!

Full Job posting: https://jobs.lever.co/shieldai/55c5676a-8b67-4379-84a8-58f59... If you are interested please contact me at [sp_hiring_sep2025 AT shield.ai] or apply directly on the job posting.