Senior Backend Engineer at cash-flow positive seed-stage fintech marketplace

This is a job that Jill, our AI Recruiter, is recruiting for on behalf of one of our customers.

She will pick the best candidates from Jack's network.

The next step is to speak to Jack.

Job Title

Senior Backend Engineer

Salary

Not Disclosed

Company Description

Cash-flow positive seed-stage fintech startup building a modern trading marketplace for private market stock

Job Description

Join a high-velocity engineering team redefining private market investing for institutional clients. You will design and own core backend systems, building scalable services that transform fragmented data into institutional-grade insights. This is a pivotal role for an engineer who thrives on speed and wants to ship AI-native workflows that power billions in order volume.

Location

San Francisco, USA

Why this role is remarkable

• Work on a platform that has already achieved cash-flow positivity and manages billions of dollars in live order volume for the world’s leading institutional investors.
• Play a foundational role in an elite, fast-moving engineering team where you will directly influence architecture and build AI-native products like MCP servers for LLM interactions.
• Experience the best of both worlds: the high growth and impact of a seed-stage startup combined with the stability of a proven, trusted market reputation.
  
  

What You Will Do

• Design, build, and scale core backend systems and APIs that power a modern marketplace for private company stock and research.
• Develop automated data pipelines using LLMs to ingest, structure, and enrich complex financial data from fragmented sources into high-quality datasets.
• Architect and maintain modular, event-driven services and MCP servers that enable clients to interact with platform data directly through AI agents.
  
  

The ideal candidate

• 4+ years of backend or full-stack experience, with a strong background in TypeScript or typed functional languages like Scala, Rust, or Haskell.
• Proven track record in a high-velocity, early-stage startup environment, demonstrating the ability to ship production systems quickly using modern AI development tools.
• Located in the San Francisco Bay Area and excited to collaborate in-person at least 3 days per week in a high-ownership, low-ego engineering culture.
  
  

Who are Jack & Jill?

Ok, I'll go first. I'm Jack, an AI that gets to know you on a quick call, learning what you're great at and what you want from your career. Then I help you land your dream job by finding unmissable opportunities as they come up, supporting you with applications, interview prep, and moral support.

And I'm Jill, an AI Recruiter who talks to companies to understand who they're looking to hire. Then I recruit from Jack's network, making an introduction when I spot an excellent candidate.

Next steps

Step 1. Visit the job listing.

Step 2. Click 'Talk to Jack', or go straight there: https://www.jackandjill.ai/jobs/senior-backend-engineer-at-cash-flow-positive-seed-stage-fintech-marketplace-233e9562-56f3-4738-a163-71f3ade11e7c?utm_source=linkedin&utm_medium=job_post&utm_campaign=featured_role_233e9562-56f3-4738-a163-71f3ade11e7c

Step 3. Talk to Jack so he can understand your experience and ambitions.

Step 4. Jack will make sure Jill (the AI agent working for the company) considers you for this role.

Step 5. If Jill thinks you're a great fit and her client wants to meet you, they will make the introduction.

Step 6. If not, Jack will find you excellent alternatives. All for free.

We never post fake jobs

This isn't a trick. This is an open role that Jill is currently recruiting for from Jack's network.

Sometimes Jill's clients ask her to anonymize their jobs when she advertises them, which means she can't share all the details in the job description.

We appreciate this can make them look a bit suspect, but there isn't much we can do about it.

Give Jack a spin! You could land this role. If not, most people find him incredibly helpful with their job search, and we're giving his services away for free.