Senior Software Engineer - Payments and Platform (Backend)

Senior Software Engineer — Backend

Payments & Platform

BukuWarung Engineering  •  4–6+ Years Experience

About BukuWarung

BukuWarung is building the financial and digital nervous system for millions of underserved merchants across Indonesia — payments, credit, software, and money management converging into one integrated platform. We build infrastructure that small businesses depend on to survive.

We are in a critical phase of growth. The systems we build today need to be designed for 10x and 100x scale — reliability, correctness, and architectural depth are not things we bolt on later.

About the Team — Payments & Platform

The Payments & Platform team owns three interconnected areas: the shared backend platform that every tribe depends on (core infrastructure services, developer primitives, and the integrations layer); the money-movement infrastructure that powers disbursements and transfer rails across the company; and direct merchant-facing payment products where correctness and uptime are requirements, not aspirations.

Tech Stack

Java Spring Boot, PostgreSQL, Apache Kafka, Redis, AWS, DataDog, PagerDuty

The Role

We are looking for a Senior Software Engineer with experience in high-stakes, transaction-heavy systems. You will work across payment infrastructure and platform services, and your decisions will directly affect the reliability of merchant money flows.

What You Will Do

• Design and build backend services for payment infrastructure — idempotency guarantees, retry queues, reconciliation flows, and crash-safe state management

• Own systems in production — monitor, respond to incidents, and continuously improve reliability, not just ship and move on

• Partner with product and business stakeholders to translate requirements into well-scoped engineering solutions, driving work end-to-end from design through to production

• Contribute to shared platform services that every tribe depends on, and drive system design reviews that raise the engineering bar

• Proactively identify hard problems — race conditions, ordering guarantees, blast-radius risks — before they reach production

• Instrument services for observability and own alerting for the systems you build

• Communicate risk, tradeoffs, and timelines clearly to both technical and non-technical stakeholders

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

• Mentor engineers and build reusable patterns that raise the team's collective output

What We Hold the Bar On

1. Correctness on Money-Movement

Our systems move real merchant money. Idempotency, crash recovery, and safe state management are first principles — engineers here design with failure in mind from the start.

2. Proactive Risk Identification

We look for engineers who surface edge cases, failure modes, and architectural risks early — and come with a view on how to address them, without waiting to be asked.

3. Considered Use of AI Tools

We expect engineers to use AI tools to move faster — and to bring the judgment to validate outputs critically and take full ownership of what gets shipped.

What We Are Looking For

Required

• 4–6+ years of professional backend software engineering experience

• Bachelor's degree in Computer Science, Engineering, or a related technical field

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

• 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

• Working knowledge of cloud infrastructure (AWS preferred) and container-based deployments

• Ability to instrument and own observability and alerting for the services you build

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

Strong Signals

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

• Designed idempotency, retry logic, and reconciliation flows from scratch — not just consumed them

• Evidence of thinking ahead of the build: design docs, RFCs, post-mortems, or open-source contributions

Why This Role

At large companies, you optimise a slice of a mature system. Here, you shape the spine of a platform that millions of merchants depend on. Your architecture decisions have company-wide impact, you will mentor others and influence engineering culture — and the work is real infrastructure, not ad dashboards.

If you are someone who thinks in systems, gets uncomfortable when architecture feels fragile, and wants ownership beyond tickets — we would love to talk.