Staff Backend Engineer | JVM

About Addi

We are a leading financial platform, building the future of payments, shopping, and banking-a world where consumers and merchants can transact effortlessly and grow together. Today, we serve over 3.6 million customers and partner with more than 55,000 merchants, making Addi Colombia’s fastest-growing marketplace.

With a state-of-the-art, technology-first approach, we provide banking solutions (deposits, payments, unsecured credit) and commerce services (e-commerce, marketing), bridging the financial gap for millions and redefining how people experience financial freedom. As the country’s leading Buy Now, Pay Later provider, we have secured regulatory approval to operate as a bank, unlocking even greater opportunities for our customers. In the past year, we have also achieved profitability, reinforcing the strength of our business model and our ability to scale sustainably.

Our mission has earned the trust of world-class investors, including Andreessen Horowitz, Architect Capital, GIC, Goldman Sachs, Greycroft, Monashees, Notable Capital, Quona Capital, Union Square Ventures, Victory Park Capital, and more, who back our vision for the future. With their support, we are not just growing-we are transforming Latin America’s financial ecosystem and shaping the next generation to shop, pay, and bank in Colombia.

But what truly sets us apart is how we build. We are a conscious company, driven by deep experience in scaling technology, services and products, and we live byour values every day.

About the Role

This is where you come in. Below, you’ll find what this role is all about-the impact you’ll drive, the challenges you’ll tackle, and what it takes to thrive at Addi. If you’re ready to be part of something big, keep reading.

What’s the mission you’ll drive

As a Staff Backend Engineer, you will drive Addi’s backend technical direction, platform architecture, and engineering standards across squads. Your goal is to help every team build fast, securely, and AI-natively on systems that are ready to scale. Over the next 12 months, you will make sure the credit, payments, and marketplace services that our customers and allies across Latin America rely on stay reliable and secure as we grow, without having to rebuild the foundations along the way. This is an individual contributor role with company-wide technical leadership: you won’t manage people, but you will influence how many teams build.

What you will do

• Deliver at least one material business result in your domain, such as better payment success rates, faster and safer onboarding, a marketplace flow that converts more, or a faster delivery pipeline for every squad.

• Work with Product, Risk, and Growth to re-engineer the backend of our highest-volume revenue flows (credit decisioning and onboarding, ally checkout and payments, repayments and collections), so we cut latency, failed transactions, and manual workarounds and more people get approved and can pay without friction.

• Own the health of the platform you land in, end to end: reliability, scalability, performance, security, cost, and how easy it is to operate.

• Design and push adoption of shared foundations like service templates, shared libraries, messaging and event standards, and CI/CD and release practices, together with Platform/SRE and the squads that use them.

• Set and support SLOs and error budgets by service tier, lead root-cause analysis on the hardest production incidents, and help make sure the same problem doesn’t bite us twice.

• Turn our backend security and quality standards (authN/authZ, PII, OWASP/PCI, secrets and dependency scanning, contract and integration tests on key flows) into CI gates that every squad follows.

• Roll out our agentic coding setup (AGENTS.md conventions, skills, spec templates, and CI gates for tools like Claude Code and Factory Droid) so every backend squad builds AI-natively and agent-written code ships safely.

• Shape the technical direction by writing RFCs and ADRs on things like service boundaries, data ownership, event contracts, consistency and idempotency, testing, and security, and by getting them adopted as the backend standard.

• Mentor Senior engineers and help some of them grow toward Staff and Tech Lead roles.

• Be part of incident leadership and the on-call culture. We move money and make credit decisions, so this comes with the territory.

What we’re looking for

• Deep expertise in backend and distributed systems at scale

  • 15+ years building production software, with 8+ years owning the architecture of large-scale distributed backend systems.

  • Expert in the JVM ecosystem (Java, Kotlin, or Scala, with Spring Boot), with strong command of SQL/PostgreSQL, Redis, messaging (Kafka, SQS, RabbitMQ), event-driven design, AWS, and Kubernetes.

  • You can walk us through an architecture you designed (service boundaries, data consistency, messaging, zero-downtime rollouts) that held up as traffic and the team grew.

• Proven experience driving technical decisions with org-wide impact

  • 4+ years at Staff, Principal, or Software Architect level, driving decisions across multiple squads, not just one.

  • You write RFCs/ADRs, get buy-in from engineers, product, and leaders, and push your ideas all the way to adoption.

  • You have created a shared standard (a platform service, a service communication pattern, a data ownership model) that 4+ teams adopted.

• Strong judgment on technical tradeoffs

  • You balance speed, reliability, cost, and long-term maintainability, and you make calls with incomplete information in a fast-moving startup.

  • You have led big re-architectures or modernizations (like breaking down a monolith or redesigning a core domain) while the product kept shipping and without hurting availability or the business.

  • You own the outcome of your decisions and can explain what worked, what didn’t, and why.

• AI-native engineering mindset

  • You use agentic CLIs (Claude Code, Factory Droid, or similar) as your default way of writing code, not just an occasional helper.

  • You have set up the harness for a whole team or org (AGENTS.md conventions, skills, spec templates, CI gates) so agent-written code ships safely.

  • You write specs before code and feed what you learn back into conventions and tooling.

• Background in performance, security, quality, and reliability

  • You have defined SLOs and delivered measurable wins (availability, p95/p99 latency, throughput, infra cost) with a clear before and after.

  • You have defined security practices across teams (authN/authZ, PII and data protection, OWASP, PCI) and testing strategies across unit, integration, contract, and end-to-end.

  • You have led root-cause analysis on complex production incidents and advised teams beyond your own area.

• Strong cross-functional influence and business sense

  • You connect backend decisions to credit risk, payments, conversion, and cost, and you can explain them to CTO/VP level without jargon.

  • You align Engineering Managers, Product, Risk, Security, and Data around priorities using data, for example by making the case for a scalability fix over a new feature.

  • You influence without authority through credibility, clear writing, and good arguments.

• Experience in fintech, lending, or payments

  • You have owned high-volume payment, credit decisioning, ledger, or onboarding systems at a fintech, bank, or marketplace.

  • You understand the realities of regulated financial products: idempotency, reconciliation, auditability, compliance, and trust.

  • Nice to have: working knowledge of the backend’s edge, like API gateways, GraphQL/BFF layers, third-party integrations (payment processors, credit bureaus), and auth flows end to end (OAuth, token issuing and refresh).

• Track record of growing senior talent and shaping engineering culture

  • You have mentored engineers who later got promoted to Senior or Staff.

  • You have shaped hiring, review processes, or engineering guilds that the org still uses.

  • You have helped raise the technical hiring bar as a calibrated interviewer.

Why join us?

• Work on a problem that truly matters - We are redefining how people shop, pay, and bank in Colombia, breaking down financial barriers and empowering millions. Your work will directly impact customers' lives by creating more accessible, seamless, and fair financial services.

• Be part of something big from the ground up - This is your chance to help shape a company, influencing everything from our technology and strategy to our culture and values. You won’t just be an employee-you’ll be an owner

• Unparalleled growth opportunity - The market we’re tackling is massive, and we’re growing faster than almost any fintech lender at our stage. If you’re looking for a high-impact role in a company that’s scaling fast, this is it.

• Join a world-class team - Work alongside top-tier talent from around the world, in an environment where excellence, ownership, and collaboration are at the core of everything we do. We care deeply about what we build and how we build it-and we want you to be a part of it.

• Competitive compensation & meaningful ownership - We believe in rewarding our talent. You’ll receive a generous salary, equity in the company, and benefits that go beyond the basics to support your growth.

How the hiring process looks like

We believe in a fast, transparent, and engaging hiring experience that allows both you and us to determine if there's a great fit. Here’s what our process looks like:

• Step 1: People Interview (30 min)

  Meet with our recruiter for a 30-minute video chat. We will get to know you better, understand what you’re looking for, and answer any questions you might have about ADDI.

• Step 2: Initial Interview (45 min)

  Meet with one backend software engineer for a 45-minute video chat interview. Here, we will ask you questions about your technical background and basic computer science concepts. You will be able to ask any questions about the culture and how we work at ADDI.

• Step 3: Take Home Challenge (1 week)

  Complete a simple take-home challenge within a 1-week window. With this technical challenge, we want to see your technical expertise solving a real-world problem. We expect that you invest 5 hours or less in developing a working solution.

• Step 4: Deep Dive Interview (60 min)

  Meet with a backend software engineer and the engineering manager for a 45-minute chat to talk about your take-home exercise submission and any questions you might have.

• Step 5: Co-Founder Interview (30 min)

  Meet onsite with one of our founders for a 30-minute chat to talk about the vision of the company, what we are building and how you will contribute to our product.

We value efficiency and respect for your time, so we aim to complete the process as quickly as possible. Our goal is to make this experience insightful and exciting for you, just as much as it is for us. Regardless of the outcome, we are committed to always providing feedback, ensuring that you walk away with valuable insights from your experience with us.