Backend AI - Ruby on Rails, PostGreSQL, Performance optimization

Job Description

Job DescriptionBackend / Platform Engineer, AI-Powered Consumer Fintech (San Francisco)Company Overview

A stealth-mode consumer fintech startup is building an AI-native companion designed to transform how individuals make real-time spending decisions. Moving beyond traditional "after-the-fact" budgeting apps, the platform lives within iMessage to provide instant context, trade-off analysis, and financial guidance at the exact moment of purchase. The company is led by two founding team members from Chime and is backed by top-tier investors including Crosslink Capital, Fiat Ventures, and Blueprint (Jay-Z and Jack Dorsey’s fund). They are currently in a high-velocity, pre-launch phase, focused on building the next iconic consumer brand in finance.

What Makes It an Awesome Place to Work

• Founding Team Pedigree: Work alongside early leaders from Chime who have successfully scaled fintech products to millions of users.
• Top-Tier Backing: Secured funding from prestigious investors like Crosslink Capital and Blueprint, providing both stability and a massive network.
• High Autonomy: A true 0 → 1 environment where you have a direct voice in product strategy and architectural decisions.
• Relocation Support: Committed to an in-person culture in San Francisco with assistance provided for moving expenses.
• Meaningful Ownership: Offers significant equity stakes and the opportunity to scale into a leadership role as the engineering organization grows.

Scope of Role and Experience

As a Backend / Platform Engineer, you will:

• Become a core contributor to the Ruby-on-Rails backend systems powering a commerce-enabled AI companion.
• Ship high-impact features, integrations, and data pipelines weekly to maintain rapid development velocity.
• Design and implement reliable integrations with financial APIs and LLMs to create a seamless, "magical" user experience.
• Handle complex data modeling for transactions, user context, and AI retrieval systems (RAG).
• Establish the foundation for backend architecture, monitoring, and deployment processes.
• Collaborate closely with product and design to translate ambitious concepts into scalable technical reality.

You have:

• Strong experience in Ruby and Ruby on Rails development (core development and architecture).
• Deep knowledge of PostgreSQL performance tuning and query optimization.
• A track record of thriving in 0 → 1 environments with high autonomy and ambiguity.
• A "builder" mindset—you prioritize shipping and craft over bureaucracy and bloat.
• The ability to take end-to-end ownership of technical projects from ideation to production.

Nice to have:

• Experience shipping fintech products or working with financial APIs (e.g., Plaid, Quiltt).
• Hands-on experience integrating AI/LLMs into production-grade systems.
• A desire to move into a lead or management role as the company scales.

Location: In-person (San Francisco, CA)

Perks: Competitive startup salary, meaningful equity, and comprehensive medical/dental benefits.