Senior Full Stack Developer (React)

Senior Full-Stack Developer, Enterprise Applications

Job Locations US | Remote

***Although this is a remote position you will be required to interview one round onsite at a nearby Partsauthority 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:

1. Describe a production system you built that integrates an LLM API. What went wrong the first time, and how did you fix it?
2. 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?
3. 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?

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 + TypeScript 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/TypeScript 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 PostgreSQL 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.

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, SQLAlchemy or equivalent ORMs, async patterns, service-layer architecture) and React (hooks, context, component libraries, TypeScript, 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 building user-facing AI features. Experience with ML model serving (MLflow, SageMaker, or equivalent).
• Kafka and Event-Driven Architecture. Experience building or maintaining systems using Kafka (or equivalent) for asynchronous event processing, change data capture, or inter-service communication. Understanding of topics, partitions, consumer groups, at-least-once delivery, and operational realities of event-driven systems.
• PostgreSQL + Redis. Experience designing relational schemas for multi-module applications, writing migrations, and using Redis as a caching layer with TTL strategies and invalidation patterns.
• Proficiency in JavaScript/TypeScript, including modern ES6+ syntax.

Strongly Preferred

• Real-Time Application Experience. Familiarity with WebSocket-based architectures (Socket.IO or similar), real-time data synchronization patterns, and fallback strategies such as API polling.
• Mapping and Geolocation SDKs. Experience with Google Maps JS API or comparable mapping libraries for location-based features.
• Wholesale Distribution or Automotive Aftermarket Domain. Experience in B2B wholesale, distribution, supply chain, or the automotive aftermarket. Familiarity with concepts like aging buckets, credit holds, payment terms, tiered pricing, route-based delivery, and seasonal demand patterns.
• Databricks / Data Lakehouse. Experience with Databricks SQL, Delta Lake, the medallion architecture (Bronze/Silver/Gold), or MLflow model registry.
• Computer Vision Integration. Experience with multimodal AI (image + text), particularly using vision APIs for object detection, OCR, or image classification in production applications.
• Kubernetes / DevOps. Experience with container orchestration, Helm charts, CI/CD pipelines (GitHub Actions), blue/green deployments, or infrastructure-as-code.
• IBM i / AS400 Integration. Any exposure to AS400 — ODBC connectivity, RPG program interfaces, Data Queues, journal-based CDC, or DB2 for i SQL. Experience integrating modern web applications with legacy ERP systems.

Technology Environment:

You will be working within a modern, enterprise-grade technology stack that includes:

• Frontend: React 19, TypeScript, Tailwind CSS, Recharts/D3
• Backend & Cloud: Python 3.12, FastAPI, SQLAlchemy ORM, Pydantic
• Databases: PostgreSQL (multi-schema), Redis Cluster (6 nodes)
• Messaging: Apache Kafka (10+ topics, CDC patterns)
• Data Warehouse: Databricks SQL Warehouse, Delta Lake (medallion architecture), MLflow
• ERP Integration: IBM i AS400 via ODBC, Data Queue API, PCML, CDC via Kafka
• AI/ML: Anthropic Claude (text + vision), Google Gemini, Databricks MLflow
• Infrastructure: Kubernetes (Nutanix AHV), Docker, GitHub Actions CI/CD
• Monitoring: Grafana, Zabbix, TimescaleDB
• Security: Okta SSO, HashiCorp Vault, Arctic Wolf
• Version Control & Methodology: GitHub, Agile/Scrum

Some of the benefits of being a part of our growing Parts Authority family:

• Medical Coverage
• Pharmacy Coverage
• Dental Coverage
• Vision Coverage
• Basic Life and AD&D
• Short Term Disability Coverage
• Voluntary Short Term Disability Coverage
• Voluntary Long Term Disability Coverage
• Flexible Spending Account
• Commuter Expense Reimbursement Account
• Health Savings Account
• Health Reimbursement Account
• Accident Insurance
• Critical Illness Insurance
• Hospital Indemnity Insurance
• ID Theft Insurance
• Legal Plan Insurance
• Pet Insurance
• Employee Assistance Program (EAP)
• Paid Holidays, Sick and Vacation
• Profit Sharing/401 (k) Plan
• Employee Discounts on Merchandise

We are an Equal Opportunity Employer.  All persons shall have the opportunity to be considered for employment without regard to their actual or perceived race, color, creed, religion, national origin, ancestry, citizenship status, age, sex or gender (including pregnancy, childbirth, related medical conditions and lactation), gender identity, sexual orientation, marital status, military service and veteran status, disability, protected medical condition as defined by applicable state or local law, genetic information or any other characteristic protected by applicable federal, state or local laws and ordinances.  We will consider for employment all qualified applicants, including those with criminal histories, in a manner consistent with the requirements of the Los Angeles Fair Chance Initiative for Hiring Ordinance.

We will endeavor to make a reasonable accommodation to the known limitations of a qualified applicant with a disability unless the accommodation would impose an undue hardship on the operation of our business.

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