Principal Backend Engineer

We are Heron, a Series A company based in New York and London. Come help us end the underwriting tax.

• The problem is big and still largely unsolved. Every time a small business applies for a loan, advance, or insurance policy, people still spend hours manually reading documents, checking businesses, detecting fraud, and deciding what to offer. Small businesses pay for that friction through slower decisions, worse economics, and products that are too expensive to exist. When underwriting gets dramatically easier, financial products get better and cheaper.
• We are building the software to automate it. Heron handles the work from intake and bank statement scrubbing through background checks, cashflow analysis, fraud detection, and decisioning, all inside the systems our customers already use. We analyze 60K submissions a day across 200+ funders, brokers, and fintechs, covering roughly 15% of US businesses seeking capital.
• Your work reaches real customers, fast. Underwriters use Heron every day to make real financial decisions. Engineers ship to production in their first week, and you will usually know exactly who your work helped because you will probably have talked to them. What you ship this week can change how a funder operates next week.
• You will own problems, not tickets. We hire pilots, not passengers. Nobody waits around to be told what to do. You spot the problem, understand it deeply, own the outcome, and ship the solution. At ~60 people, there are very few layers between you and the impact of your work.
• We move fast because we get close to the problem. We fly to Gainesville to sit beside customers and watch them work. We label transactions by hand before automating them. We will build the website by tomorrow when that is the fastest way to learn. Speed here does not mean cutting corners. It means understanding the problem well enough to move decisively. And we are radically candid with each other because the best teams give feedback continuously, directly, and with care.
• This is an unusually early moment in a very large market. Small business underwriting remains deeply manual, leaving a huge amount of open ground. Customers keep pulling us into new workflows and new problems faster than we can build for them, so we raised a $16M Series A from Insight Partners, alongside Y Combinator, to keep going. Joining now means you are not inheriting a finished playbook. You are helping write it.
• We work together in person. Our teams are based in NYC and London, with travel between the two offices. We offer top-of-the-line equipment, competitive compensation and equity, healthcare, 401(k), fertility benefits, and take-what-you-need vacation. We have weekly team lunches, always inclusive. Applicants from every background are welcome, and we have zero tolerance for discrimination.

Read more about our mission at herondata.io/mission.

Heron processes millions of sensitive financial documents for some of the fastest-growing MCA Funders, Brokers, Insurers, and Fintechs in the US and UK. We're at a point where the volume, velocity, and complexity of the data flowing through our systems and is outgrowing the way they were originally built. We need someone who's done this before: taken a platform that works and made it scale.

We've built a document automation and workflow orchestration platform that lenders, funders and fintechs rely on to make real decisions. It's working, customers love it, and we're onboarding new ones faster than ever.

The challenge is that our backend was built for speed-to-market, and now we need to make it built for scale. Concretely, that means:

• Abstractions that let us move fast: The backend systems and patterns that let a 15-person engineering team ship product confidently without breaking things for existing customers.
• Multi-tenancy at scale: Dozens of enterprise customers sharing the same cloud infrastructure, each with different data sensitivity requirements, SLAs, and integration patterns.
• Data volume and velocity: High-throughput processing of financial documents (bank statements, tax returns, pay stubs) with ML pipelines that need to be fast, accurate, and reliable.
• Security and compliance: Sensitive financial data handled to exacting standards.

We’re excited about this challenge because it is the kind of problem that shows up when things are going well! We're hiring this role because we couldn’t be more confident in our trajectory but need to build the foundations for the next 10x.

This is a hands-on, high-autonomy IC role. You'll work directly with our CTO (Dom) and Head of Engineering (Oli), and you'll have real ownership over the systems that matter most.

In your first few months, you'll likely:

• Assess our current backend architecture and identify the highest-leverage areas for improvement around reliability, scalability, and security.
• Partner with the platform and infrastructure team to design and implement the core abstractions (data model, data pipeline reliability, deployment patterns) that will support our next phase of growth.
• Set the technical direction for how we scale our infrastructure from handling hundreds of customers to thousands, and from millions of documents to tens of millions.
• Raise the bar on backend engineering practices across the team: not through process for process's sake, but by building systems that make the right thing the easy thing.

Longer-term, this role shapes how Heron's entire platform evolves. You'll be the person who ensures our backend can support whatever product throws at it.

The best person for this role has likely spent 8+ years building and scaling backend systems, with at least a couple of meaningful "at-bats" taking a system from early stage to serious scale. You've probably worked in B2B SaaS and have opinions (earned the hard way) about how to build systems that are both reliable and fast to develop on.

More specifically:

• You have a strong CS foundation and are deeply technical. You write code, review architectures, and debug production issues.
• You've seen and built backend systems scale at companies growing from Series A to Series C+ (roughly $5M to $100M+ ARR). You know what breaks and when.
• You have recent production experience with Python and cloud infrastructure.
• You've dealt with sensitive data at volume: financial, health, or similarly regulated domains.
• You're an IC at heart. You might set direction and mentor others, but you want to build, not manage.
• You care about getting things right but also about shipping. We're a startup. Pragmatism matters.

• Competitive compensation, including equity
• Based full-time in London or NYC, where most of the team is in-person multiple days per week
• Your choice of top-of-the-line equipment to fit out your desk in the office
• Occasional travel for retreats and to work with the team
• Competitive benefits: health insurance; pension/401k; uncapped annual leave; parental leave
• Free mental health support via Spill - on-demand access to therapy
• Weekly company lunches (always inclusive and vegan-friendly - especially if you like Korean or Vietnamese food!)
• Applicants from any background and gender are welcome and we have a zero tolerance policy on discrimination

• Customer dashboard -- NextJS, using React, TypeScript, deployed on Vercel
• Backend application -- Python (Flask or FastAPI)
• Backend infra -- Celery / RabbitMQ, Postgresql, Kubernetes. Heavy data processing typically done async
• Inference -- in-house LLMs and external LLM providers
• GitHub for repos & GitHub actions for CI/CD

• Initial screen (20 minutes) - conversation to discuss what you're looking for, what Heron offers, and to see if there's a good fit.
• Technical screening interview (up to 60 minutes) - interactive technical session with one or two of our engineers where you will review a pull request and then do some live coding to build on it.
• Team interviews (2-3 hours in total) - mix of technical and behavioral conversations with Heron teammates and founders. You'll get a feel for the people you'll work with and how we approach problems, and we'll get to know how you collaborate, communicate, and think.
• References - 2 references from people you've worked with who can speak to your impact, working style, and contributions in a professional setting.