Senior Software Engineer

 

Senior Software Engineer

Location: San Francisco, CA

Company Stage of Funding: Series A / AI + Fintech + Accounts Receivable Automation Startup

Office Type: On-site (5 days/week in San Francisco)

Salary: $210,000 – $240,000 Base

Equity: Competitive Equity

Bonus: Competitive total compensation package

Visa: No sponsorship available

Company Description

Our client is building AI agents that automate accounts receivable for enterprise companies.

The company replaces one of the most manual and operationally painful back-office workflows with AI-native software that improves collections, invoicing, reconciliation, and cash flow operations.

Founded in 2023 by Harvard and MIT alumni, the company is backed by Y Combinator and Gradient (Google's AI venture arm) and recently raised a $17M Series A.

The company is still early enough for engineers to have foundational ownership while already demonstrating strong traction, enterprise demand, and rapid scaling momentum.

The platform combines:

• AI-powered accounts receivable automation

• Invoice orchestration

• Collections workflows

• Cash application systems

• ERP integrations

• Event-driven backend infrastructure

• Full-stack fintech applications

• Enterprise workflow automation

• Data reconciliation systems

• Operational finance tooling

Engineering challenges involve building reliable fintech systems, event-driven architectures, full-stack product experiences, scalable APIs, safe database migrations, observability, and automation infrastructure for enterprise finance teams.

The culture values ownership, speed, engineering excellence, autonomy, mentorship, and building software that directly impacts customer operations and revenue cycles.

What You Will Do

• Design and build full-stack product features across frontend and backend systems

• Develop scalable APIs and backend services for enterprise finance workflows

• Build customer-facing applications using Next.js, React, and TypeScript

• Own schema design, database migrations, and backfill strategies using Prisma and MySQL

• Build and maintain event-driven workflows using tools like Inngest or Temporal

• Drive architectural decisions across the platform as the first senior engineering hire

• Establish engineering best practices around observability, incident response, and runbooks

• Mentor engineers through code reviews and system design discussions

• Collaborate directly with founders on product direction and technical trade-offs

• Improve system reliability, uptime, and deployment safety in a high-stakes fintech environment

• Build end-to-end workflows spanning UI, API, database, and infrastructure layers

• Participate in system design and architecture planning for a rapidly scaling product

• Help define the engineering culture and technical standards as the team grows

• Ship production-grade software with significant autonomy and ownership

• Build infrastructure powering enterprise accounts receivable automation at scale

Ideal Candidate Background

• 5+ years of experience in full-stack software engineering

• Experience at early-stage startups, ideally sub-30 employee environments

• Experience scaling B2B SaaS products from early users to meaningful ARR

• Strong proficiency in TypeScript across frontend and backend systems

• Experience with Node.js, Next.js, React, Prisma, and modern web stacks

• Experience building and operating event-driven systems

• Strong system design and architecture skills

• Experience owning products or major features end-to-end

• Strong software engineering fundamentals

• Ability to operate independently with minimal direction

• Experience mentoring engineers through code review and design review

• Comfortable working across frontend, backend, infrastructure, and data layers

• Experience building enterprise SaaS or fintech products preferred

• Degree from a top-tier CS program preferred

• Strong startup mindset and ownership mentality

Strong Signals

• Founding Engineer or early engineering team experience

• Experience at YC-backed or high-growth VC-backed startups

• Experience at companies like Stripe, Plaid, Brex, Mercury, Datadog, Airbnb, or similar engineering cultures

• Strong TypeScript and React expertise

• Deep Node.js backend experience

• Experience with Prisma, MySQL, and schema migrations

• Experience with event-driven tools such as Inngest or Temporal

• Fintech, payments, AR/AP, or enterprise finance domain experience

• Track record of scaling B2B SaaS systems in production

• Demonstrated architectural ownership in small, high-performing teams

• Experience improving engineering standards, observability, and operational maturity

• Strong mentoring and technical leadership capabilities

• Ability to thrive in ambiguous, fast-moving startup environments

• Experience shipping high-quality full-stack products independently

Compensation and Benefits

• Base salary: $210,000 – $240,000

• Competitive equity package

• Opportunity to join a fast-growing Series A AI fintech company

• Significant ownership over architecture and product direction

• Direct collaboration with founders and executive leadership

• Exposure to AI-native enterprise automation and fintech infrastructure

• High autonomy and influence as the first senior engineering hire

• Opportunity to shape engineering culture during a critical growth phase

• Work on meaningful operational problems with direct customer impact

• Onsite collaboration with a highly ambitious engineering team in San Francisco

• Career acceleration through broad ownership and visibility

Why Join

This is an opportunity to become the foundational senior engineer at a breakout AI fintech company attacking a massive and underserved operational problem.

Rather than building incremental SaaS features, the company is redesigning enterprise accounts receivable workflows from the ground up with AI-native automation.

You'll work directly with founders, own major technical decisions, and help build the engineering foundation for a company that is scaling rapidly after a major Series A raise.

The role offers a rare combination of full-stack engineering, fintech infrastructure, AI-enabled workflows, architectural ownership, mentorship, and startup impact.

If you enjoy building systems end-to-end, shaping engineering culture, operating with high autonomy, and solving real enterprise problems, this role offers exceptional scope and upside.