Backend Engineer

Member of Technical Staff: Backend

Monk is an AI-native accounts receivable (AR) platform for B2B companies helping businesses get paid fast.

The AR stack is broken. Finance teams still chase payments with spreadsheets, reconcile AR in spreadsheets and use software that was built a decade ago. We think this is one of the largest, most ignored problems in B2B software. Trillions of dollars sit in outstanding invoices and the tools to unlock cashflow are stuck in the past. We are rebuilding Monk with AI, speed, and real craftsmanship.

We are already doing this for over $1B of accounts receivables. We are backed by leading investors and our founders bring significant experience to our company (more here).

We are early, the upside is enormous, and the hardest, but also the most rewarding work is ahead of us.

The role:

We're looking for a backend engineer to join us in person in Flatiron, NYC. You'll own the foundational systems everything else runs on: the data layer, the integrations, the AI runtime environment, and the infrastructure that has to be right every time money moves between businesses. We care about one thing: whether you can build systems that scale, stay up, and get faster as we grow.

In this role you will:

• Build core agent infrastructure at the applied layer: Design and ship the system that powers Monk’s agentic products

• Own systems end to end: Build and maintain enduring financial architecture designed for agents

• Build for the future: Manage, evolve, and extend your architecture and design to thousands of use cases that slow down payment in B2B

• Own reliability at scale: Build and own monitoring, alerting, and incident response to get our customers paid fast

• Ship fast: Land changes that help customers daily and default to action

Who you are:

• 4+ years building and operating production backend systems. You've built them, broken them, and scaled them yourself

• A T-shaped engineer: deep in at least one area, broad enough to push the rest forward, and you do it in TypeScript/Node

• Strong with our stack and able to go deep where it counts: Postgres, AWS, data pipelines, observability

• You understand the tradeoffs you're making and you know when something has to be rebuilt instead of patched

• AI-native, not AI-dependent. You move fast with it and you know exactly when not to use it

• An owner. You don't file tickets about infrastructure problems. You fix them, and then make sure they can't happen again

• Excited to build in person in Flatiron, NYC

Bonus if you:

• Have experience with fintech or payments data systems

• Have built backend infrastructure for LLM or agent products

• Were a founding or early backend hire

Our values (we hope that you will add your DNA/values and impact our culture as you build with us):

• Ownership and craft: We own our work end to end and obsess over getting the details right. We believe that our Customers deserve the best possible outcomes and we strive to produce work that would get a 12/10 reaction from either our Customers or members of our team. Ownership is also knowing when to go deep on a problem and when to move fast. And when the v1 is live - we own all follow-through until it is perfect

• Speed and urgency: We ship daily. We act now. Not tomorrow and not the end of the week, but today - this hour. We love shipping fast to delight our Customers

• Radical clarity: We believe in getting to the truth. It is important that all of us reason from the same version of reality (the truth) so that we can get the best result. We strive to get the truth by any means necessary. This means being open to feedback, obsessing over improving from our mistakes and clear communication

Why solve this problem now:

• A broken market and a real shot at owning it. AR is huge, ignored, and ready to be rebuilt. We're early and the surface area is enormous

• $T+ market and max EV from a single AR wedge

• No clear winner has emerged in this massive category. It can be us

• Insulated from labs. This workflow is complex, too many integrations are required and the last mile in AR is too bespoke for general purpose models

• Hard problem worth solving. Revenue intelligence is challenging and inherently unsexy. Frankly, there are fewer strong companies in our space and we are building the most talent-dense team

• Undeniable $ROI that allows us to clearly illustrate value to Customers, and embeds us into integral workflows

• Our unfair advantage: We have ex-finance founders that have previously exited, scars and learnings from those experiences, an eng-first culture and late-mover advantage

Why build with us // what we offer:

• You want to be a founder someday. We are sharing everything we’ve learned building our past companies (25% of the team are 2nd time founders). One of our primary goals is to help you become a founder and create a place where you do your life’s best work (see more here)

• Real ownership and an opportunity to 10x your learning curve. You will see your work go to production and deliver results for Customers, fast. Your own experience is the greatest teacher and at Monk we are maximizing the # of times you get to have valuable experiences

• Build at the frontier of applied AI and solve hard problems. You are curious about AI and do not want to miss this moment building at the frontier

• Experienced founders that have exited before and a motivated team that is all-in

• Competitive salary and meaningful equity

• Medical/dental/vision, flexible paid time off and dinner stipend

• Beautiful office in Flatiron, New York

We hire for intensity, craft, and attitude. We believe that most things can be learned.

Category defining companies are built with exceptional people. Our team is one of the products we're shipping = come help build it.