River | Senior + Staff Engineers (Elixir, React, ML/AI) | SF or NYC or REMOTE (US, Europe, South America) | Full-Time | $150K-$250K + equity | https://jobs.ashbyhq.com/river?utm_source=Zp9nJyqvd4

I'm Alex, founder and CEO of River. I also wrote the first line of code and still ship PRs.

River is a client-first Bitcoin-only financial institution building the financial app people use every day to save in bitcoin and spend in dollars. We custody over 25,000 BTC, serve individuals and businesses across the U.S., and are profitable. We publish cryptographic proof of reserves monthly and our company financials annually.

Here's what our engineering team is working on:

  - Real-time Bitcoin and USD payments, trading, and settlement on an Elixir monolith with a unified GraphQL API
  - Next-generation Bitcoin custody with quorum signing, key ceremonies, and geo-redundant infrastructure
  - Scaling our ML/AI systems (Python, PyTorch, XGBoost, LLMs) to automate operations and tackle fraud/risk
  - A ground-up React and React Native rewrite of our consumer app
  - Porting our Lightning Network infrastructure from Go into Elixir

  - Staff Software Engineer (Elixir) | $200K-$250K
  - Senior Software Engineer (React, Full-stack) | $150K-$220K
  - Senior/Staff Machine Learning Engineer | $200K-$250K

Lineation | Rust/TypeScript/React/GraphQL/PostgreSQL | Senior Software Engineer | Contractor Part-Time | Remote (US-friendly time zones) | https://lineation.ai

We’re building an Agentic AI Security Platform that helps teams secure autonomous AI workflows. We’re looking for a senior engineer to help design and ship core systems across policy enforcement, runtime monitoring, incident workflows, and auditability.

You’ll work across backend and product surfaces: Rust + gRPC services, GraphQL APIs, and TypeScript/React interfaces for security operations. You should be comfortable owning features end-to-end, making pragmatic architecture decisions, and collaborating closely with product/security teams in a small, fast-moving environment.

Strong fit if you have experience with distributed systems, secure-by-default engineering, and production observability. Security product background is a plus, but not required if you’re excited to learn quickly and build in this space.

If this sounds interesting, email us at [hello@lineation.ai] with Resume/CV plus links to your GitHub/LinkedIn and a short note on systems you’ve built.

Join (https://join.build) | Staff Software Engineer | Remote | $175K–$205K + equity Join builds collaboration software for the construction industry — helping contractors, owners, and architects coordinate on high-value projects. React, Golang, Postgres. We deploy to AWS via Terraform.

We're hiring multiple staff engineers across a range of profiles: frontend-heavy, fullstack, and backend-heavy. We're especially looking for 1–2 engineers with architect-level frontend chops (React, TypeScript, state management, perf) who can own UI quality and level up the team. But we're also very interested in strong Go/Postgres or infra/ops backgrounds.

Day to day you'll write code (25–75%), review PRs (25–50%), and pair/mentor/document (10–20%). You'll act as a technical lead on projects, break down large efforts, and influence architectural decisions across the org. Small cross-functional teams with a designer, PM, and EM.

Stack: React, TypeScript, Golang, Postgres, GraphQL/Apollo, Vite, Cypress, Terraform, AWS (ECS, RDS, Lambda). We lightly use Elastic and are interested in event-driven patterns.

Fully remote, 100% employer-paid medical, 401(k), two company-wide shutdown weeks, continuing education budget.

To apply: send resume to jon@join.build. If you are able to please include a PR review you've given that had a positive impact (or a description/snippet if that's confidential).

Shepherd | ONSITE | San Francisco, CA

At Shepherd, we're pursuing the most ambitious technical vision in commercial insurance: fully autonomous underwriting. Shepherd is an AI-native commercial insurance platform transforming how high-hazard industries get covered.

The infrastructure behind the AI boom (data centers, semiconductor fabs, renewable energy assets) has to be built and insured, but traditional carriers weren't built for this speed. We built Shepherd to solve that.

We just recently announced our $42M Series B! That brings our total funding to over $60M — led by Intact Private Capital, the investment arm of one of the largest insurers in the world. Intact is not only our lead investor but also a carrier partner, a testament to the confidence the incumbent industry has in what we're building.

(Hear from our CEO here: https://www.shepherdinsurance.com/blog/behind-our-42m-series...)

(Hear from our CTO here: https://www.shepherdinsurance.com/blog/the-road-to-autonomou...)

This year, we’re growing our engineering team from 25 to 40. We’re looking for product-minded engineers to join us as we continue to scale! We’re looking for someone who thrives on ownership, drives results, and cares deeply about both technical excellence and customer impact.

We’re hiring various mid-level, senior-level and staff-level engineers. See some of our openings below:

* Full Stack - Job Posting: https://jobs.ashbyhq.com/shepherd/c4081c3d-a79b-4ac9-aa19-78...

* Backend - Job Posting: https://jobs.ashbyhq.com/shepherd/395f4b75-cf05-4581-8408-8f...

* Founding Machine Learning Engineer - Job Posting: https://jobs.ashbyhq.com/shepherd/797316b4-bdcc-4c0c-8bc2-46...

* Applied AI Engineer - Job Posting: https://jobs.ashbyhq.com/shepherd/26959124-aab2-446e-aa4d-72...

Our stack includes: Typescript, React, Next.js, GraphQL w/ Apollo, Node.js, Postgres & Redis

Apply here: https://shepherdinsurance.com/careers

* In the form, be sure to mention that you heard about this opportunity via Hacker News. If you want to read more about our team and culture, check out our blog: https://shepherdinsurance.com/blog