Rayni (https://www.rayni.ai) | Chicago - Hybrid or Remote | Full-time | Founding Full Stack Engineer

Mission: We accelerate scientific discovery. We are starting with helping scientists operate their instruments (like Mass Spectrometers) faster with our Gen AI-powered platform.

Impact: We help scientists develop new drugs faster, analyze diseased blood samples faster, study brain cancer faster, etc.

Funding (> $1.5M): Funded by tier-1 VCs, including winning the biggest academic accelerator program on the planet - New Venture Challenge at the University of Chicago. Past winners include Venmo and Grubhub, among others, over the last 25+ years.

Who are we hiring: 3+ YOE in full-stack engineering with a frontend focus (80%) and backend (20%).

You will: - Make fundamental decisions about the frontend stack and product vision - Work with scientists to convert their needs into features. - Long term: Help build the product engineering team, lead and mentor new engineers - Long term: Scale the product to millions of users

Complete job post: https://rayni.notion.site/founding-full-stack-engineer-2412a... More about the company, culture, and benefits: https://rayni.notion.site/rayni-careers-2312a8a0f8fe803ab5bb... Founding Story: https://polsky.uchicago.edu/2025/07/02/how-rayni-turned-scie...

CreativeMode (S24) | https://creativemode.net | On-site - San Francisco, CA

CreativeMode is building Lovable for video game mods, starting with Minecraft. In our first three months, we built the most powerful no-code modding platform ever for Minecraft and created a double digit percentage of all mods ever released. We're building an entirely new category of gaming tools. Minecraft is only the beginning.

We're hiring a Founding Engineer who wants to build at the intersection of tech and gaming. Ideal candidates have a passion for the category and have experience building production-level LLM/AI applications or are killer full-stack engineers who can own product features end to end.

Ideally 3+ years of experience

Email me at Email is hidden with your resume and a short blurb on why you'd like to join the team.

Roundtable | https://roundtable.ai | On-site San Francisco, CA | Full-time

Roundtable is a research and deployment company building the proof-of-human layer in digital identity. Roundtable seeks to research and build real-world Turing Tests, and to productize these developments in bot detection, fraud prevention, and continuous authentication.

We're hiring a Member of Technical Staff. This is not a typical “Founding Engineer” position. In particular, this role will involve more research than similar positions. You should be prepared to spend around half of your time on research and half on engineering.

The ideal candidate has experience in both. However, we don’t strictly require research experience as long as you have a strong quantitative background and an eagerness to learn. We do require proficiency in both web development (Javascript, Node.js) and Python.

If you're interested shoot an email to Email is hidden with your resume and a short blurb on why you're interested (note: we are unable to offer visa sponsorship at this time).

Spacelift | Remote (Europe) | Full-time | Senior Software Engineer | $80k-$110k+ (can go higher)

We're a VC-funded startup (recently raised $51M Series C) building an infrastructure orchestrator and collaborative management platform for Infrastructure-as-Code – from OpenTofu, Terraform, Terragrunt, CloudFormation, Pulumi, Kubernetes, to Ansible.

On the backend we're using 100% Go with AWS primitives. We're looking for backend developers who like doing DevOps'y stuff sometimes (because in a way it's the spirit of our company), or have experience with the cloud native ecosystem. Ideally you'd have experience working with an IaC tool, i.e. Terraform, Pulumi, Ansible, CloudFormation, Kubernetes, or SaltStack.

Overall we have a deeply technical product, trying to build something customers love to use, and have a lot of happy and satisfied customers. We promise interesting work, the ability to open source parts of the project which don't give us a business advantage, as well as healthy working hours.

If that sounds like fun to you, please apply at https://careers.spacelift.io/jobs/3006934-software-engineer-...

You can find out more about the product we're building at https://spacelift.io and also see our engineering blog for a few technical blog posts of ours: https://spacelift.io/blog/engineering

Additionally, we're hiring for a new product we're building, Flows[0]. Mostly the same requirements and tech stack, without the devops bits. If you'd like to apply specifically for that, just mention "new product" in the cover letter field.

[0]: https://events.spacelift.io/devops-next

/Noona | GO/VUE | REMOTE

/$3500mo → $100K-300K FTE + 0.5%-3% equity

/Our final boss is to de-throne Yelp with co-op

/Founding Engineer? Email is hidden https://x.com/trynoona

Loop | loop.com | Engineering, Product | On-site San Francisco, CA, Chicago, IL

Loop is on a mission to unlock profits trapped in the supply chain (https://www.loop.com/article/unlock-profit-trapped-in-your-s...) and lower costs for consumers. Bad data and inefficient workflows create friction that limits working capital and raises costs for every supply chain stakeholder.

Loop’s modern transportation cost management platform uses our domain-driven AI to harness the complexity of supply chain data and documentation. We improve transportation spend visibility so companies can control their costs and power profit. That is why industry leaders like Nvidia, Verizon, Dell, J.P. Morgan Chase, ABB, Estee Lauder, Tyson Foods, Yeti and Olipop, work with Loop.

1. Raised $100m+ from JPM GEP, Founders Fund, 8VC, Susa Ventures, Flexport, Index.

2. 250+ paying enterprise customers with multiple-year contracts.

3. High-caliber team of engineers and operators from Google, Scale AI, Flexport, Uber, Rakuten, Square, Meta, Stanford, Brown, Princeton, and Yale.

Fullstack Engineer San Francisco - https://job-boards.greenhouse.io/loop/jobs/4102236004

Fullstack Engineer Chicago - https://job-boards.greenhouse.io/loop/jobs/4830548004

AI Engineer San Francisco - https://job-boards.greenhouse.io/loop/jobs/5391540004

Product Manager, San Francisco - https://job-boards.greenhouse.io/loop/jobs/5602148004

Engineering Director, San Francisco - https://job-boards.greenhouse.io/loop/jobs/5597686004

Other roles at https://www.loop.com/company/careers

Neuralwatt | https://neuralwatt.com | REMOTE (US – Seattle/Denver/Boulder metros only) | Full-time | $180k–$220k DOE Energy is the #1 constraint in new datacenter buildouts. Neuralwatt is reshaping AI compute around energy efficiency to maximize revenue per kilowatt. We’re a VC-backed, early-stage startup building optimization tools for AI, HPC, and datacenter workloads.

We're hiring 2 experienced founding engineers to help architect our core systems and work directly with customers.

What you'll do:

Technically: Architect critical datacenter infrastructure - Write Rust and Python - Measure real-world energy impact - Design state-of-the-art AI-led optimizations

Non-technically: Help build the business and win customers - Present at conferences - Develop marketing and company materials

Requirements:

- 5–10+ years of software development experience

- Thrive in ambiguous, outcome-driven environments

- Experience working closely with customers

- Clear communication and strong leadership

- Familiarity with LLM/AI infrastructure

Location: Remote-first, but we meet regularly in Seattle/Denver metro areas.

To apply: Email: Email is hidden Subject: HN Hiring Include: - Resume - GitHub profile - A short note on why you're interested.

Please note: At this time, we are unable to offer visa sponsorship.

Stainless | Engineers, EMs, Former Founders, GTM, Business, more | NYC & SF ONSITE | Full-time

Stainless is building the platform for high-quality, easy-to-use APIs.

When you `npm install openai` or `pip install anthropic` or `go get …cloudflare`, for example, you’re downloading code that we generated.

We’re ~3y old, ~35 people, have strong revenue, several years of runway, and great customers (including OpenAI, Anthropic, and Cloudflare). We’re backed by Sequoia & a16z.

As one of our first 30 engineers, you’ll get autonomy to build great products, skilled peers, opportunity for tremendous impact, and competitive salary, benefits, and equity.

We’re looking for exceptionally productive, thoughtful, tasteful, and kind people with a passion for making software development better for everyone.

Want to build the future of API tooling? See more at stainless.com/jobs

Elyos (https://elyos.ai) | London, UK | ONSITE | YC S23

Company: We're the UK's fastest growing AI voice company (~30% MoM) - very deeply focused on the trades industry right now (think your friendly neighbourhood plumbing company).

We're a small but experienced team hiring 3 more to join:

- Founding Engineer - Founding SDR - Founding Operations Lead (customer success)

Tech: GKE, python, postgres, telephony/media streaming, realtime LLMs, contextual eou detection, the occasional REST API.

https://careers.elyos.ai/ or message me - Email is hidden

Mention bananas for extra kudos.

krea.ai | Distributed Systems Eng. & Data Engineers | San Francisco (on-site), CA

I'm the cofounder & CTO of Krea (https://www.krea.ai).

We are a startup in San Francisco building browser-based AI creative tools to improve the workflows of artists, designers, and professional creatives.

Small team (~20); millions of active users; and raised over $83M from top Silicon Valley investment firms.

We're looking for talented engineers who want to tackle hard technical challenges with smart people while building a creative platform that big companies and startups will rely on.

The job:

- Build distributed systems to process massive (billions of files, petabytes), amounts of image, video, and 3D data, solving scaling bottlenecks as you go.

- Build data pipelines and deploy ML models to make sense of raw data (e.g. find clean scenes within videos).

- Learn ML engineering from world-class researchers on a small tight-knit team. As you’re building data pipelines, you’ll contribute to foundation image, video, and world models from 0 → production, and see them used by millions of Krea users.

- Play with massive amounts of compute on huge Kubernetes GPU clusters; our main GPU cluster takes up an entire datacenter from our provider.

Tech stack: python, pytorch, k8s, a rotating cast of data tools (e.g. DuckDB, massive relational DBs, PyArrow, etc.)

You should apply if you are an excellent generalist engineer with strong backend experience and an intuition for systems design. Bonus points for deep experience with distributed systems, kubernetes, and existing ML or data experience (but not required!). Cool side projects are a green flag.

A few links about us:

- Sneak peek of our real-time video model → https://x.com/krea_ai/status/1961074072487620635

- Technical report for FLUX.1 Krea, our first open-source text-to-image model → https://krea.ai/blog/flux-krea-open-source-release

- HN discussion around FLUX.1 Krea → https://news.ycombinator.com/item?id=44745555

You can contact me at:

Email is hidden (the +hn will bump your email in my inbox)