Senior Engineer - (Python Backend & AI)

Fulfil is the modern ERP for commerce. Our platform handles:

Order Management & Fulfillment — Millions of orders monthly, warehouse operations, inventory across locations

Financial Systems — Automated accounting, bank reconciliation, revenue recognition for merchants processing millions in revenue

Integrations — Shopify, Amazon, 3PLs, carriers, EDI — thousands of orders per minute flowing through our connectors

You'll join one of three engineering teams based on your interests and experience.

Monday : Lead design review for a system that needs to handle 10x current scale. Whiteboard with the team, make the architecture call.

Tuesday : Build a prototype. Benchmark against production data. Ship the first version.

Wednesday : Call with a merchant. Walk through their operations — whether that's warehouse workflows, month-end close, or multi-channel selling. Translate their problems into solutions.

Thursday : Code review for SDE-IIs. Guide them on edge cases, performance, and reliability patterns.

Friday : Deploy to production. Monitor it handling real traffic. Start planning next week.

Architecture decisions that affect millions of transactions

System reliability and performance at scale

Technical direction for your domain (with Product Lead)

Mentoring engineers on your team

Direct relationships with merchants using your systems

6+ years building backend systems

Expert Python skills — you've worked in large, mature codebases

Deep PostgreSQL knowledge: query optimization, transactions, data integrity

Experience with distributed systems: Celery, Redis, RabbitMQ, or similar

Strong debugging skills across services and system boundaries

Clear communication with both engineers and non-technical stakeholders

You ship fast and take ownership

E-commerce, logistics, or warehouse systems

Financial systems, fintech, or accounting software

Integration platforms, third-party APIs at scale

Python, Flask, PostgreSQL, Redis, Celery, RabbitMQ, SQLAlchemy, Kubernetes, pytest, Claude Code, etc.

Initial interview — What you've built and owned

Live coding — Real-time problem solving

Interview loop — Architecture, system design, bar raiser

Bootcamp — Even senior engineers start in Product Support to learn how merchants use Fulfil

Leverage LLMs (OpenAI API, Claude API) to embed AI-driven capabilities into Fulfil’s ERP , powering natural language interfaces, intelligent automation, and merchant-facing insights ( e.g., Fulfil x MCP integrations with Claude) .

Focus on AI for commerce operations — integrating models to solve real problems like order management, financial analysis, customer insights, and logistics optimisation.

We are not a core ML/AI research company — we don’t train or fine-tune foundation models.

We focus on integration and productisation of AI , not building new ML frameworks or developing custom model architectures.

Most weeks are 45-55 hours; peak seasons (BFCM, major launches) hit 60+

Occasional off-hours calls with our distributed team or for customer launches

Long days (10+ hours) aren’t uncommon

The work doesn’t pause even if we try to protect your focus time

Real autonomy over execution (we measure impact, not facetime)

Ownership of problems that matter to real businesses

Unlimited PTO we actually want you to use (we’d rather you rest than burn out)

If you’ve ever felt like you’re capable of 10x more than your current environment allows you to output, that’s the gap between your potential and your actual impact. Fulfil eliminates that gap.

You’ll thrive here if: you’re the type who gets energy from building something that matters, want ownership over outcomes vs tasks, are open to receiving regular, direct feedback in public Slack channels from multiple people, and like moving fast without red tape.

This isn’t for you if: you need a strict 40-hour boundary, prefer structured oversight, or want work to be a contained part of your life.