Senior Full Stack Developer; React

Position: Senior Full Stack Developer (React)
Overview

Senior Full-Stack Developer, Enterprise Applications

Job Location s US | Remote

* Although this is a remote position you will be required to interview one round onsite at a nearby Parts authority location
* Parts Authority is building an enterprise platform from the ground up - a custom-built system designed specifically for the automotive aftermarket wholesale business, with deep integrations into our AS400 ERP, Databricks analytics lakehouse, and AI services including Anthropic Claude and Databricks MLflow. This is not a COTS implementation or a Salesforce customization project.

We are seeking a highly skilled Senior Full-Stack Developer to join as one of the first engineers on the build team. You will have direct influence over technical decisions, code patterns, and system design. As the platform scales, this role grows into a technical lead position with responsibility for mentoring junior developers and guiding module development across the team.

This is a high-visibility project with direct stakeholder engagement at the CEO and CIO level. Your work will be demonstrated to executive leadership regularly, and you will see the direct business impact of what you build - from a 75% reduction in customer onboarding time to AI-generated insights that drive millions in collection and sales activity.

How to Apply

Submit your resume along with a brief note (2-3 paragraphs) answering one of these questions:

Describe a production system you built that integrates an LLM API. What went wrong the first time, and how did you fix it? You need to connect a modern Python API to a legacy system that supports only 20 concurrent connections but handles all business-critical transactions. How do you design the integration layer? Tell us about a time you had to present a technical trade-off to a non-technical executive.

What was the decision, and how did you frame it?

Responsibilities

What You'll Build

You will help design and deliver a modular enterprise platform consisting of integrated modules. Key areas of focus include:

* Shared Platform Core:
Backend services powering authentication, RBAC, caching, event streaming, ERP integration, and a unified AI orchestration engine shared across all modules.

* AI-Powered Business Tools:
Intelligent features including automated email generation, computer vision-based customer onboarding, demand forecasting, anomaly detection, and natural language querying - all integrated with Anthropic Claude and Databricks MLflow.

* Operational Modules:
Real-time dashboards, action queues, territory management, route optimization, lead pipelines, and executive scorecards used daily by collections teams, 100+ field sales reps, and senior leadership.

* Modern Frontend: A responsive React 19 + Type Script SPA with a shared component library, module-based routing, and tablet-optimized design for field use.

Responsibilities

* Design, build, and ship production features across the full stack - Python/FastAPI backend services and React 19/Type Script frontend modules.

* Architect and maintain the shared platform core including authentication, RBAC, audit logging, caching, and the unified AI orchestration engine.

* Integrate LLM APIs (Anthropic Claude text + vision, Databricks MLflow) into production workflows - designing prompt chains, managing token budgets, implementing response caching, and handling rate limits and fallbacks.

* Build and maintain Kafka-based event-driven integrations across 5 modules, AS400 CDC, and the Databricks analytics pipeline.

* Design relational schemas in Postgre

SQL for a multi-module application, write migrations (Alembic), and implement Redis caching with TTL strategies and invalidation patterns.

* Develop and consume RESTful APIs for seamless integration with core systems including AS400 ERP (ODBC, Data Queue API), Databricks SQL Warehouse, and third-party services.

* Collaborate with IT teams and business stakeholders to translate operational needs into technical requirements. Present to executives, demo to business users, and communicate technical trade-offs in business language.

* Contribute to developer experience improvements - monorepo structure, API contract design, shared component libraries, test strategies, and documentation.

* Participate in Agile/Scrum ceremonies and contribute to a 24-week MVP delivery timeline.

Qualifications

5+ years of professional experience building production web applications, with at least 2 years at a senior level making architectural decisions.

* Full-Stack Proficiency. Production-level experience with both Python (FastAPI or Flask, SQL Alchemy or equivalent ORMs, async patterns, service-layer architecture) and React (hooks, context, component libraries, Type Script, Tailwind or equivalent).

* AI/ML Integration Experience. Hands-on experience integrating LLM APIs (Anthropic Claude, OpenAI, or equivalent) into production applications - designing prompt chains, managing token budgets, implementing response caching, handling rate limits and fallbacks, and…