Alembic | SF (5 days onsite) | SRE • C++ AI • Backend Python • Data Engineering

Causal AI at scale for Fortune 500. We melted GPUs building this—now running one of the world's fastest private supercomputers. The only non-Fortune 500 company in the world to operate such a system. Customers: Nvidia, Delta, Mars. $145M Series B.

Hiring now: SREs for supercomputer infrastructure, C++ engineers for AI systems, data engineers for enterprise-scale pipelines, backend Python engineers for our platform.

Story: https://venturebeat.com/ai/alembic-melted-gpus-chasing-causa...

Job Board: https://jobs.ashbyhq.com/alembic?utm_source=LrrO1q3Bmk

x2A | NYC, NY, USA | ONSITE | https://x2a.tech

We are actively looking for multiple software developers or software engineers to join our team (in the office, 5 days/week). These positions primarily focus on our 5off software product (puzzles/games).

There is zero expectation for you to be proficient in all aspects of the tech stack. We are looking for people who know some of these technologies and are excited to share their expertise while developing their skills and learning new things.

We welcome candidates at any experience level, with or without academic qualifications. For junior candidates, do not hesitate to share related personal projects.

Tech stack:

  - Languages: Python, Typescript, Swift, Rust, C++.
  - Backend: SQLAlchemy, PostgreSQL, Litestar.
  - Frontend: Svelte, Tailwind.
  - Mobile: Swift, SwiftUI.
  - Cloud: AWS, AWS CDK.
  - DevOps: Gitlab.

Compensation: 115k-170k based on experience and skills.

More https://x2a.tech/careers/openings/ for more details and how to apply.

Microsoft AI | Platform Engineering | Full-time | Seattle, WA or San Francisco Bay Area | ONSITE (4 days/week)

We're building the platform primitives that power https://copilot.com (Microsoft's ChatGPT). If you've shipped systems at scale—whether backend services, distributed infrastructure, ML platforms, or consumer AI products—we want to talk to you.

The work: design and build secure, performant platform services for AI at scale; collaborate with infrastructure, product, design, and research teams; ship high-quality code that reaches hundreds of millions of users; move fast in a design-driven environment.

You: solid fundamentals in systems thinking and software engineering; fluent in Python, C#, C++, Java, JavaScript, or similar; shipped real products or systems people use; can communicate across technical and non-technical teams.

Compensation: Competitive with other frontier AI companies, commensurate with experience

We're actively hiring and will respond to applicants. Check https://microsoft.ai/careers for current openings, or email maiplatformjobs@microsoft.com if something specific doesn't fit the bill. Apply directly if genuinely interested in building the future of AI.

xAI (Yes, we just got acquired by SpaceX, no, I can't talk about it)

We're the truth-seeking AI (Grok) that accelerates human scientific discovery and deepens our collective grasp of reality.

We're looking for the very best technical talent globally (in-office) - Palo Alto or SF / Seattle / Memphis / NYC / London / Dublin / Tokyo / Dubai / Singapore

292 jobs are currently open - https://job-boards.greenhouse.io/xai

Software Engineers - We're flexible, but think Rust / C++ / Python / Typescript / React

Infra/SRE - k8s / Terraform / ArgoCD / Go

Grok Engineers - machine learning fundamentals, including model evaluation, training and fine-tuning / Python / Typescript

If you're an Engineer and not sure what the best fit is, try applying for one of our 'Exceptional' roles and we'll assess where we think you'll fit: London - https://job-boards.greenhouse.io/xai/jobs/4956070007 Palo Alto - https://job-boards.greenhouse.io/xai/jobs/4956028007

Last step - if you want some assistance, email me at mspiers@x.ai - Include 'hackernews' in subject line and please attach your CV.

Freeform (http://freeform.co ) | Software Engineers | Full-time | Onsite | Hawthorne, CA (Los Angeles County)

Freeform is deploying metal 3D printing factories at global scale and setting a new frontier in manufacturing. With AI, GPUs, and FPGAs working in tandem, our system monitors and corrects every microsecond of the process, delivering a level of precision, speed, and quality that’s never been possible—until now. This isn’t just an improvement; it’s a leap forward in how complex metal parts are made, with the ability to revolutionize industries like aerospace, defense, automotive, energy, and beyond. We are backed by top VCs including NVIDIA’s NVentures, Founders Fund, and Threshold Ventures.

It’s a small, tight-knit team and you’d have the opportunity to own significant and impactful greenfield projects throughout the entire development lifecycle and much more. Our software team comes from the likes of Google, SpaceX, and Apple, and believe in taking a first principles approach to solving hard problems.

A glimpse into our software landscape - https://youtu.be/nFWQArUkd5I?si=mP17qdKbxvf8qpZN

Our feature in TechCrunch! https://techcrunch.com/2024/10/22/ex-spacex-engineers-land-1...

+ Senior Software Engineer, Factory Software C++ (Skyfall) - https://grnh.se/ddgoq9yh3us

+ Senior Software Engineer (Embedded) - https://grnh.se/5eerse413us

+ Senior Software Engineer (Edge Data & Telemetry) - https://grnh.se/j8jyvaj03us

+ Software Engineer (Edge Data & Telemetry) - https://grnh.se/9z8omwl13us

Category Labs | https://www.category.xyz/ | Remote and NYC | Full Time | $200K USD+

Category Labs (formerly known as Monad Labs) is a team of systems engineers and researchers on a mission to design and build at the frontier of decentralized technology. We strive to design and build step-function improvements over existing blockchain solutions. After raising $225M in series A funding, led by Paradigm, we are growing our team.

Technical Program Manager: https://jobs.ashbyhq.com/category-labs/bdfe89a6-83f6-4ab3-b6...

Senior SWE, Compiler: https://jobs.ashbyhq.com/category-labs/e5c34899-cea1-4d25-be...

Smart Contract Engineer (Solidity): https://jobs.ashbyhq.com/category-labs/776ce314-aa12-471b-92...

Senior SWE (Rust, C/C++): https://jobs.ashbyhq.com/category-labs/45f674b2-d904-482e-a5...

Senior Researcher, Systems: https://jobs.ashbyhq.com/category-labs/015934c5-66e5-4042-94...

BitRipple | USA | Full Time | Remote - Prefer domestic USA but open to Non-Restricted Countries

We are hiring two Developer positions: - Senior Software Engineer: Network layer communication optimizations - Senior Software Engineer: GPU porting / RDMA / NCCL / NIXL layer development

We are a deep-tech company building the next generation network communication layer for AI, squeezing out GPU idle time during LLM training with accelerated RDMA communication across clusters. If you love deep systems work and high-performance networking, you will fit right in.

We also service many other networking related industries like mobility, satellite, aerospace, atmospheric optical, VPN, SD-WAN and defense.

- What you’ll do - Design and implement high-throughput, low-latency transport and flow-control logic (think TCP/QUIC/UDP, congestion control, pacing) but next level. Optimize end-to-end performance (CPU/GPU/IO), and ship results that move real workloads.

- What you bring - Proficient in C, C++, Rust Strong grasp of networking transport protocols & flow control concepts. Solid math foundation. You understand memory management, concurrency, throughput and efficiency at scale.

- Nice to have - Mobile (Android/iOS) development knowledge. GPU porting experience. NCCL / NIXL / DPDK integration experience. RDMA/RoCEv2/Infiniband/NVLink knowledge . FEC/erasure coding knowledge.

Interested? Send your resume to: work@bitripple.com You will be talking directly with: Mike Luby, CTO: https://www.linkedin.com/in/michaelluby/ or myself Scott Brown, CEO: https://www.linkedin.com/in/scott-k-brown/

Stellar Science | Hybrid (USA) Albuquerque NM, Washington DC (Tysons VA), Dayton OH | Full time, interns/co-ops | U.S. citizenship required | https://www.stellarscience.com

Company: We're a small scientific software development company that develops custom scientific and engineering analysis applications in domains including: space situational awareness (monitoring the locations, health and status of on-orbit satellites), image simulation, high power microwave systems, modeling and simulation, laser systems modeling, AI/ML including physics-informed neural networks (PINN), human body thermoregulation, computer vision and image processing, high performance computing (HPC), computer aided design (CAD), and more. All exciting applications and no CRUD. We emphasize high quality code and lightweight processes that free software engineers to be productive.

Experience: Except for interns, we currently require a Bachelors degree in physics, engineering, math, computer science, or a related field. Masters or PhD is a plus. (Roughly 25% of our staff have PhDs.)

Technologies: Lots of C++23, Qt 6.9, CMake, git, OpenGL, CUDA, Boost, Jenkins. Windows and Linux, msvc/gcc/clang/clangcl. AI/ML and analysis projects use Python and C++. Web projects use Java and Typescript/React.

Apply online: at https://www.stellarscience.com/careers/.

SIG | Multiple Positions | SYDNEY, AUSTRALIA | Visa Sponsorship for Experienced / PhD Candidates | On Site | https://sig.com

SIG is a global quantitative trading firm founded with an entrepreneurial mindset and a rigorous analytical approach to decision making. As one of the largest proprietary trading firms in the world we are experts in trading all listed financial products and asset classes handling millions of transactions on exchanges around the world every day.

SYDNEY:

Quantitative Systematic Trader

Quantitative Researcher

C# Developer (Post Trade Technology)

C++ Developer

Pricing Developer (C#, Python)

Python Developer

Application Support Engineer

Technical Analyst - AI

If you have not previously applied please send me your CV (email in the profile). We had few great YC hires already in the past. Contact number, visa/work rights, availability and a brief description of your current situation is useful to include.

Encube Technologies | Senior & Lead Software Engineers Onsite (Stockholm) or Remote | Full-time

Encube Technologies is building collaborative, real-time software for manufacturing. We are looking for experienced engineers to help shape the core of the product.

You will work on challenging problems at the intersection of browser-based 3D rendering, CAD compute algorithms, and real-time collaboration, with a strong focus on end users and performance. This is hands-on, product-driven engineering with significant technical depth.

What you will work on - High-performance, browser-based 3D rendering - Compute-heavy CAD and geometry algorithms - Real-time, multi-user collaboration features - Systems bridging frontend graphics and backend compute

Tech stack

Frontend - React, Next.js, TypeScript

Graphics - WebGPU, WebGL2, three.js, React Three Fiber

Backend - Python microservices with occasional C++ bindings - Kubernetes-based infrastructure

We are hiring Senior and Lead Engineers who enjoy ownership, care about product quality, and like solving difficult technical problems with real-world impact.

Apply via our website: https://www.getencube.com/we-are-encube

Please mention in your cover letter that you found Encube Technologies via Y Combinator.

Tenzir | Software Engineering & Sales | Remote (EU Timezones) | Full-time

Tenzir is building an open-core security data pipeline for the AI era. We empower defenders to collect, shape, and route security telemetry at scale. Our stack relies on C++23/26 and Apache Arrow for the core engine, with a modern TypeScript platform layer.

We are hiring for 4 key technical roles to join our distributed team (HQ in Hamburg):

- Software Engineer (Core Engine): Systems programming with C++23/26. Work on our pipeline language, query execution, database integrations, and streaming data processing with Apache Arrow.

- Software Engineer (Product): Full-stack TypeScript/Python focus. Build the control plane, platform APIs, and developer tools, AI workflows, and anything else that makes our engine accessible.

- Account Executive: Our first dedicated AE to own the full enterprise sales cycle. You'll work with complex deals in security and data infrastructure.

- Solutions Engineer: Lead POCs and post-sales implementation. You'll be the hands-on engineer ensuring customers succeed with complex data pipelines.

We are a remote-first team across European timezones. If you like solving hard data problems, we'd love to hear from you.

Apply: https://tenzir.com/company/careers

Coram.ai https://www.coram.ai | Senior / Lead Software Engineers | Sunnyvale, CA or London, UK | ONSITE

Coram AI is building an AI-powered video security platform that helps enterprises proactively detect and respond to real-world incidents. We work with large-scale video data, real-time systems, and applied computer vision.

What you’ll work on: • Backend systems handling real-time video and event data • Scalable APIs and data pipelines • Production AI/ML integrations • Building reliable, user-facing features end to end

Tech stack: • Backend: Python, Go, C++ • Infra: AWS, Terraform • Data: Postgres, streaming pipelines • Frontend exposure a plus (React), but not required

You might be a good fit if you: • Have 5+ years of professional software engineering experience • Have worked on backend or platform systems at scale • Enjoy working in small teams with high ownership

Salary - $150k–$250k USD / £90k–£130k GBP + equity

https://jobs.ashbyhq.com/coram-ai

Kinelo | kinelo.com | Full-Stack Engineer (AI + Backend) | San Francisco | Onsite

Kinelo manages the new type of hybrid team that will emerge in the future: humans+AI working shoulder-to-“shoulder”.

Our first product helps human software engineering teams deliver more efficiently and more reliably by assisting in coordination and engineering management. But it’s built on a foundational layer that ingests data, knowledge, and process across communications and systems, exposing that to humans and AI alike.

Eventually, Kinelo will become a proper human+AI orchestration layer, managing entire companies, and our goal is to have Kinelo run Kinelo (we already dogfood it today).

We’re looking for high ownership individuals to join our small team and shape its direction. We also just opened a new SF office and new hires will have the ability to help shape company culture, engineering practices, architecture, and roadmap.

We’re well-funded (just raised another round), founded by a serial founder, anti-bureaucratic, and highly technical.

We’re looking for:

- Those who want to go 0 to 1 with high ownership: moving features and products from idea on a napkin, to prototype, to engineering UI, to shipped and polished product

- ~8 years professional experience, including the pre-LLM days with strong CS fundamentals

- A balance of wisdom from experience and optimism about the future

- Strong TypeScript and Postgres (or other RDBMS) experience at scale and with high reliability (SaaS apps, APIs, etc)

- Experience with a variety of technologies, including containerization, distributed systems, and at least one strongly typed programming language (Go, C++, Java, etc)

- Ideally experience with ML and AI systems (though expertise in ML, data science, etc is not needed for this role)

We can’t sponsor visas but relocation assistance to SF is possible.

Please apply here: https://job-boards.greenhouse.io/kinelo/jobs/4088659009 and also email jobs@kinelo.com, mentioning this post.

Beacon AI | San Carlos, CA | Hybrid (On-Site) | Full-Time | www.beaconai.co

Beacon AI builds intelligent systems that make aviation safer and more autonomous. We’ve completed multiple DoD programs and are expanding our team with exceptional technical leaders to push the boundaries of human-machine collaboration in the cockpit. At Beacon, you will lead by example, mentoring and growing a small team of talented engineers (typically 1–2 to start) while staying hands-on in design and execution. You’ll help shape critical systems that advance aviation safety and autonomy, working alongside a team that values effort, creativity, and accountability.

We’re hiring Lead Engineers with 5-9 YOE who love solving complex problems. At Beacon, you’ll own your work end-to-end, from prototype to deployment, and literally see your code take flight in real world aviation environments! Roles:

++ Lead iOS Engineer [Tech Stack: Swift, SwiftUI, UIKit, Mapbox]

++ Lead Infra/Backend Engineer [Tech Stack: AWS]

++ Lead WebApp/FrontEnd Engineer [Tech Stack: Python, Typescript, React]

++ Lead Autonomy/Robotics Engineer [Tech Stack: C++, Python, iOT]

Join us at beaconai.co/careers. Mention in the application that you saw our post on HN.

ClickHouse | Senior Cloud Software Engineer - Distributed Systems / Cloud Databases / Kubernetes | Remote

Hiring in the US right now. Seniors/Staff/Principal levels.

ClickHouse is a popular, Open-Source OLAP Database. We are ClickHouse Inc, the company behind the database aiming to build the best in class real time data warehouse.

What we are looking for:

Distributed Systems / Cloud Engineers to build the AutoScaling Systems for a Cloud Database.

We also maintain our own ClickHouse-based Data Infrastructure. Bonus points if you've worked on auto-scaling or other data-driven forecasting challenges in the past.

    Can work in an early stage startup environment. Proactive and hands on.

    You must be independent and self-organized.

    Good at Go, Kubernetes (Understanding how to manage stateful services in a multi-cloud environment) and Distributed Systems in general.

    SQL / ClickHouse SQL (goes without saying)

    You'll need to be able to do On-Call - debugging production infra or db issues

    If you can do low-level database programming (C++, ClickHouse) that's added bonus.

If you want to work on operating production critical databases in the cloud on k8s + write data-driven algorithms for autoscaling, consider applying! Send me an email: manish.gill [at] clickhouse [dot] com

[0] https://www.youtube.com/watch?v=AFoMsLMZKik

[1] https://www.youtube.com/watch?v=ufY_JFPpzRI

PS: If you're a pure DevOps person or a pure Data Engineer who wrangles data tools, please read the above requirements carefully before firing off an email. This role is an intersection of a lot of sub-roles, not a particular specialization