Software Engineer

Spadeberry is a profitable software company that helps eBay resellers create and publish better listings faster. Our customers upload photos of the items they're selling; our AI generates optimized titles, descriptions, item specifics, and pricing suggestions - then publishes directly to eBay (and now Depop, Poshmark, and Mercari). We handle background removal, category matching, and marketplace compliance automatically, so resellers can focus on sourcing.

We're profitable and growing, with a small engineering team. No outside funding, no pressure to grow fast and break things - just a profitable product that real customers depend on, and room to build the next set of meaningful features without bureaucracy.

You'd be joining a small engineering team, working directly with the founder.

What you'll work on

This is a full-stack role with a strong backend and AI lean. Spadeberry's engineering surface is wide for a team our size - and that's the point. You'll have real ownership of real systems.

AI and machine learning:

• We currently use OpenAI to generate listing content (titles, descriptions, item specifics). We're investing in building our own fine-tuned open-source model to supplement or replace that dependency - training data curation, fine-tuning pipelines, evaluation, and deployment.

• Prompt engineering, context design, and improving generation quality are core to the product.

• We invest in internal AI tooling and automation infrastructure - including experimental approaches that keep our small team operating well above its size.

Core product engineering:

• Backend: Flask 3 + Celery (task queues) + PostgreSQL + Redis, hosted on Heroku. Heavy async work - photo processing, listing generation jobs, eBay publishing pipelines.

• Frontend: upgrading from Flask/Jinja templates to a NextJS SPA. We have a dedicated front-end engineer; you'd contribute here as well.

• Mobile: React Native (iOS + Android) - our mobile app is a primary customer surface for photo uploads and listing management.

• Browser extension for power users doing bulk listing work.

Integrations and marketplace APIs:

• eBay Trading, Finding, and Inventory APIs - deep, production-grade integrations. eBay's API is quirky; you'll learn it cold.

• Cross-listing to Depop, Poshmark, and Mercari - each with their own auth flows, publish quirks, and data models.

• AWS S3 (photo storage, pre-signed URLs), PhotoRoom (background removal), Stripe (subscriptions and billing), Scout APM (production monitoring).

Infrastructure and reliability:

• We're a lean team, which means everyone cares about production. You'll investigate real errors, debug real customer issues with real data, and ship fixes the same day.

• Token-based billing system - accounting, reconciliation, and abuse prevention are all custom.

• Admin tooling: internal dashboard for account lookups, error audits, affiliate management.

2+ years of production backend engineering - you've shipped features that real users depend on.

• Comfortable in Python. Most of our backend is Flask + Celery. If you've worked in Django, FastAPI, or a similar framework, the translation is fast.

• Real experience with PostgreSQL - not just "used a database." Schema design, query optimization, understanding what a slow query actually costs.

• You've integrated with at least one complex third-party API (payments, marketplace, or otherwise). You know what it means to deal with rate limits, pagination, and underdocumented behavior.

• Comfortable debugging production issues with real data. You don't wait for a perfect reproduction - you dig into logs, read the database, and figure it out.

• Willingness to be in-office in Webb City, MO (near Joplin) full-time. No relocation support is provided.

Nice-to-have:

• Experience with LLMs in production - fine-tuning open-source models, prompt engineering, evaluation, RAG, or AI agent infrastructure. We're investing here heavily and it's where a lot of the interesting work is.

• React Native or mobile development experience. Our mobile app is a core customer surface and we need more coverage here as we scale.

• NextJS or React front-end experience. We're in the middle of a frontend modernization and need help here.

• Personal or professional experience with eBay, Poshmark, reselling, or e-commerce. Engineers who understand the domain instinctively ship better product decisions. If you've listed items on eBay yourself, that context matters.

• Heroku, Celery, Redis, or async task queue experience

• Experience at an early-stage or small engineering team

We don't care about:

• FAANG experience or big-company names on your resume

• Whether every piece of your stack matches ours - if you're a strong engineer, you ramp fast

What the work environment looks like

Pulled from the full job description

• Paid time off
• Paid holidays, You're one of a small number of engineers at a profitable company - not one of forty in a department. Your work ships, matters, and is visible.

• Work directly with Andrew (CEO/founder/chief engineer) on architecture and product decisions. No ticket queue handed down from product managers.

• In-office at our Webb City, MO headquarters (in the Joplin area)

• Engineering decisions are made by engineers. We don't have process for the sake of process.

• $65,000-$80,000 base salary based on experience + 2 weeks PTO + paid federal holidays, Pay: $65,000.00 - $80,000.00 per year

Benefits:

• Paid time off