Senior Engineer - (Python Backend)

Company Overview

At Fulfil, we’re redefining how high-growth merchants operate in a complex omnichannel world. Founded on the belief that business operations should be seamless and scalable, we’ve built a unified platform that transforms back-office challenges into growth opportunities—powering everything from order management to financial systems. Trusted by global brands like The Ridge, Hexclad, and Mejuri, we’re driving the future of e-commerce and wholesale at scale.

Headquartered in the USA and Canada, with a vibrant engineering hub in Bangalore, Fulfil is where ambitious problem-solvers come to push boundaries, master their craft, and collaborate on mission-critical technology that impacts millions.

Why Fulfil

Fulfil is a technical founder-led, bootstrapped company in our 11th year of operations. We're a small team of exceptional engineers powering millions of orders for brands like HexClad, Ridge Wallet, and Caraway. No red tape. No product managers. No layers of approval. You'll own critical systems, make architectural decisions, ship to production in your first two weeks and ship code that processes millions of orders.

You'll work directly with our Product Support team, who talk to merchants daily. They bring you real problems, you propose solutions, you ship. No PRDs. No one translating customer pain through three layers of abstraction.

At a large company, senior engineers spend their days in meetings and writing docs. Here, you'll design systems, build them yourself, and talk directly to the merchants using your code. The founders review PRs and ship code — that's the kind of company this is.

What We Build

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.

A Typical Week

• 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.

What You'll Own

• 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

What We're Looking For

• 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

Bonus points for experience in:

• E-commerce, logistics, or warehouse systems

• Financial systems, fintech, or accounting software

• Integration platforms, third-party APIs at scale

Tech Stack

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

Teams You Could Join

Hiring Process (We move fast).

1. Initial interview — What you've built and owned

2. Live coding — Real-time problem solving

3. Interview loop — Architecture, system design, bar raiser

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

Our Approach to AI

What We Do

• 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.

What We Don’t

• 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.

What It’s Really Like to Work at Fulfil
We’re building the ERP that fast-growing eCommerce brands actually want to use, which means we’re taking on entrenched enterprise software with a small, intense team.

Big Tech and VC-backed startups are 400-horsepower engines running at 25% efficiency. They have bloated teams, endless meetings, six months to ship a feature. At Fulfil, we’re a 200-horsepower engine running at 100%. We’re bootstrapped, profitable, and growing steadily. No permission layers. No “alignment meetings” about alignment meetings. Everyone ships everyday.

The work: You’ll own meaningful problems with direct customer impact. Our customers run 24/7 operations across time zones, and when they’re launching on BFCM or scaling from $10M to $100M, they need us to move fast. That urgency flows downstream. This is high-intensity work with real consequences.

What high-intensity actually means:

• 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

What you get in return:

• 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.