About the role

Build and evolve payment systems and workflows.
Develop secure APIs and integrations.
Work across backend and frontend technologies.
Engage with users for feedback and improvements.
Contribute to system architecture and quality.

Skills the posting asks for

Ruby on Rails
PostgreSQL
React

Summarised from the employer’s posting, which is reproduced in full below.

The employer’s full posting

Spectrum Search is partnered with an early-stage AI-enabled financial technology company building software for complex B2B payment and revenue workflows. The company is looking for a product-focused engineer to take end-to-end ownership of customer-facing systems across backend, frontend and AI-enabled functionality.

About the opportunity

This is a full-time engineering role within a small, highly collaborative product team. Engineers work directly across product definition, architecture, implementation, testing and measurement, with significant ownership over what reaches production.

The environment is highly iterative and AI-enabled. The team uses modern AI development tooling as part of its day-to-day engineering workflow, while engineers remain responsible for technical decisions, system quality and production outcomes.

The role

You will build and evolve systems supporting payment processing, financial workflows, integrations and AI-powered product capabilities. The role is backend-leaning but genuinely full stack, requiring engineers who are comfortable moving between application logic, databases, APIs and React-based user experiences.

You will also work directly with customer signals and feedback, helping translate real operational problems into well-scoped technical solutions.

Key responsibilities

Design, build and operate production-grade payment and financial workflow systems
Develop secure APIs and integrations with third-party enterprise platforms
Build full-stack product features across backend services, PostgreSQL and React
Develop LLM-powered workflows and agentic AI features for complex operational processes
Create evaluation frameworks, observability and guardrails for AI functionality in production
Build and maintain data pipelines processing high volumes of financial records
Own features from initial customer requirements through specification, delivery and measurement
Contribute to system architecture, technical conventions, code reviews and engineering quality

Essential requirements

Proven experience as a backend-leaning full-stack software engineer, with strong recent ownership of production systems and user-facing features
Strong backend expertise using an MVC framework such as Ruby on Rails, Django or Spring Boot
Advanced experience with SQL databases such as PostgreSQL
Ability to deliver across backend, frontend, database schema and automated testing without relying on functional hand-offs
Experience working in an environment with rapid product iteration and meaningful individual ownership
Strong product engineering mindset with experience taking responsibility beyond initial feature launch
Comfortable engaging with users and customer feedback to inform technical decisions
Active use of AI-assisted development tooling in day-to-day engineering workflows
Strong ability to decompose product requirements into clear, scoped engineering work

Nice-to-haves

Experience shipping production-grade agentic AI or LLM features
Experience with AI evaluation systems, A/B testing or multi-arm bandit approaches
Product engineering experience within fintech, payments or billing
Experience with Ruby on Rails, React, AWS or Terraform

Location and remote setup

This is a full-time, remote position for candidates based in the US. Quarterly in-person off-sites are required. Visa sponsorship is not available for this position.