Software Development Engineer II

About BukuWarung

BukuWarung is building the financial and digital nervous system for millions of underserved merchants across Indonesia. Payments, credit, software and money management come together on one platform that small businesses depend on to survive and thrive. Today that’s 8M+ app users, 250K active merchants and 60M+ transactions a year. We’re a Y Combinator (S20) company, backed by Valar Ventures and Goodwater Capital.

The Role

As a Software Engineer, you’ll build and own the high-stakes, transaction-heavy systems behind payments, merchant commerce and lending for millions of Indonesian merchants. These systems move real money, so correctness, data consistency and reliability come first, and your decisions directly affect the businesses that depend on them.

We are in a critical phase of growth, and the systems we build today must hold at 10x and 100x scale, and you’ll play a key role in making that happen.

What You Will Do

• Design, build, and maintain backend services that power high-scale, transaction-heavy payment and lending systems.

• Own problems end to end, from turning requirements into well-scoped solutions with product and business teams to rollout and monitoring in production.

• Make systems faster, leaner, and more secure by continuously improving performance, security, and infrastructure cost.

• Strengthen system observability, fault tolerance, and scalability through metrics, tracing, and alerting.

• Follow and champion engineering best practices including testing, documentation, code reviews, and CI/CD automation.

• Use AI tools to accelerate development with discipline — scope, steer, and validate the output.

Tech Stack

• Languages and frameworks: Java Spring Boot , WebFlux

• Datastores: PostgreSQL, Redis

• Messaging and queues: Apache Kafka

• Infra and monitoring: AWS, Datadog, PagerDuty

• CI/CD and tooling: Docker, Terraform, Jenkins

Familiarity with our stack helps, though it's not a must. Strong engineers pick it up fast.

Who is the right fit for this role?

To excel in this role you will need:

• 1–4 years of professional backend software engineering experience

• Strong command of system design fundamentals — distributed transactions, idempotency, event-driven architecture, caching, and fault tolerance

• Hands-on experience with relational databases and message queues in production systems

• Excellent written and verbal communication skills — able to articulate tradeoffs and risks to both technical and non-technical stakeholders

• Demonstrated ownership mindset with the ability to take initiatives from concept to production.

• Passion for clean, maintainable, and efficient code.

• A burning desire to learn and develop deep fintech expertise.

Nice-to-haves:

• Fintech, payments, or transaction-heavy platform experience where correctness is a first principle

• Proficiency in Java (Spring Boot) or equivalent JVM-based backend frameworks

Why BukuWarung

Here’s what you get that’s hard to find anywhere else

• Impact you can feel: Improve the livelihoods of millions of SEA merchants, one reliable transaction at a time

• Real money, real scale: 8M+ app users, 250K active merchants and 60M+ transactions today. Nothing teaches system design faster..

• Big-tech alumni, small-team leverage: Work with engineers who’ve built at Amazon, ByteDance, Flipkart, PhonePe, Razorpay, Gojek and Grab. The org is small enough that one engineer’s judgment changes outcomes, with no layer of translation between you and the decision.

• Engineer with agents, not just an editor: We’re AI-native, and coding agents are our standard toolchain. You’ll be able to lead agents on production systems, which very few engineers can say yet.

• Rigour most people never see from the inside: Help build a regulated, audit-grade fintech platform (PCI DSS, SOC 2, ISO 27001). This is the work that separates fintech engineers from app engineers.