Senior Software Engineer (Full Stack)

OSL; Singapore; On-site; SGD 120,000 - 180,000; Full time

Job summary

OSL is seeking a Senior Software Engineer to own the full stack of our payments platform, from Laravel services to VueJS interfaces used by customers and operations teams. You will modernize the PHP codebase while collaborating with Java services on migration paths, and you will drive reliability, observability, and scalable architecture across fiat flows and payment surface.

You will work across Laravel, VueJS, and Java (Spring Boot) with a focus on payments, reconciliation, and webhook

Qualifications

• Bachelor's degree in Computer Science, Software Engineering, or equivalent practical experience.
• 5+ years of hands-on software engineering experience, preferably in payments, fintech, or transactional systems.
• Deep PHP & Laravel experience, including major version upgrades in production.
• Will collaborate with Java (Spring Boot) when migrations require it.
• Proven PSP integrations, banking rails, reconciliation, retries, and webhooks.
• Experience with asynchronous processing and queue patterns.
• Strong AWS experience, containerised workloads, and Kubernetes familiarity.
• Production observability with Datadog or equivalent.
• Active use of AI tools in engineering workflows and a view on where it adds leverage.
• Professional English; Mandarin would be a plus.
• Agile mindset and cross-regional collaboration.

Responsibilities

• Full stack delivery across Laravel APIs, background workers, and VueJS interfaces.
• Lead platform modernization: upgrades, currency of dependencies, and structural cleanup.
• Build and maintain payment flows with PSP integrations and banking rails.
• Work across PHP/Laravel and Java/Spring Boot as flows migrate from monolith.
• Improve reliability and observability to reduce payment failures.
• Collaborate with payments, compliance, product, and operations teams.
• Leverage AI tools for coding, reviews, debugging, and documentation.
• Promote strong engineering practices, testing, and CI/CD discipline.
• Mentor junior engineers through reviews, pairing, and knowledge sharing.

Skills

PHP & Laravel

VueJS

Java (Spring Boot)

AWS

Datadog / Observability

AI-assisted development

Async processing & queues

Kubernetes

CI/CD

Agile

English proficiency

Education

Bachelor's degree in Computer Science, Software Engineering, or equivalent

Tools

Laravel

VueJS tooling

Spring Boot

Docker

Kubernetes

Datadog

CI/CD tooling

Job description

We are seeking a hands-on, versatile and results-driven Senior Software Engineer to build and evolve the full stack of our payments platform, from the Laravel services that run our fiat flows through to the interfaces our customers and operations teams use every day.

You'll own meaningful production work across our PHP (Laravel / VueJS) codebase, shipping daily against a payments surface that spans PSP integrations, banking rails, reconciliation, and the operational tooling that keeps them healthy. A core part of your remit is to modernise that codebase as it grows, upgrading the framework, tightening the schemas, and keeping it maintainable while payment flows are progressively extracted into well-bounded services. You'll work progressively and bi-directionally into our Java (Spring Boot) services where the migration path requires it.

This is a role for a senior engineer who likes range over depth-of-one-thing, and who is as comfortable tracing a failed settlement through a queue as tightening the interface an operator uses to resolve it.

Key Responsibilities

Full Stack Delivery: Ship end to end across the payments surface, from Laravel APIs and background workers through to the VueJS interfaces built on top of them, owning features through to production rather than handing them across a boundary.

Platform Modernisation: Take ownership of specific areas of the PHP codebase, driving framework upgrades, dependency currency, and structural cleanup so the platform scales with the roadmap rather than accumulating drag.

Payment Flows & Integrations: Build and maintain integrations with payment service providers and banking partners, with careful attention to reconciliation, idempotency, retries, and webhook handling across fiat rails.

Bi-directional Contribution: Work across our Java (Spring Boot) and PHP (Laravel / VueJS) codebases as payment flows are gradually extracted from the monolith, comfort moving between stacks is essential.

Reliability & Incident Reduction: Drive down payment failure rates through better observability, defensive design, and post-mortem-driven improvements, treating operational health as part of the build, not a separate phase.

Cross-functional Collaboration: Partner closely with the payments squad, compliance, product, and operations to ensure payment flows interoperate cleanly with adjacent systems and meet regulatory expectations.

AI-Assisted Engineering: Use AI tools actively in your day to day work, from code generation and code reviews to debugging, documentation, and automation. Push the squad to adopt and refine these workflows as a core part of how we ship.

Engineering Quality: Champion solid engineering practices, clean schemas, thoughtful API contracts, automated testing, and CI/CD discipline, raising the bar wherever you work in the codebase.

Peer Support: Bring less experienced engineers along through review, pairing, and clear reasoning, contributing to the depth of the wider team across regions.

Documentation & Knowledge Sharing: Maintain clear technical documentation for payment flows, integrations, and known issues, contributing to a shared knowledge base the squad and adjacent teams can rely on.

Qualifications

Bachelor's degree in Computer Science, Software Engineering, or equivalent practical experience.

5+ years of hands-on software engineering experience, with meaningful time spent on payments, fintech, or adjacent transaction-heavy systems.

Deep practical expertise in PHP and the Laravel framework, including experience carrying a production Laravel codebase through major version upgrades. This is the centre of gravity of the role.

Willingness and ability to work in Java (Spring Boot) where the migration path requires it, we are not looking for someone who will only touch one stack.

Proven experience with PSP integrations, banking rails, or payment orchestration, including reconciliation, idempotency, retries, and webhook handling.

Practical experience with asynchronous processing and queue-based systems, including patterns for retry, ordering, and dead-letter handling.

Solid working knowledge of AWS, with experience deploying and operating production services supporting a high user base. Familiarity with containerised workloads and Kubernetes is a plus.

Production observability experience, with hands-on use of Datadog or equivalent tooling for metrics, tracing, and alerting on critical service flows.

Strong understanding of databases and schema design, particularly around financial data integrity and transactional consistency.

Active use of AI tools in engineering workflows, this is a baseline expectation, not a nice to have. We expect you to bring practical experience with AI assisted development and a point of view on where it adds the most leverage. This role specifically values engineers who use AI to extend their range, not just speed up narrow tasks.

Professional working proficiency in English, with Mandarin proficiency a plus, given the team's cross-regional collaboration rhythm.

Adaptability and curiosity, with the engineering culture, troubleshooting instincts, and willingness to learn unfamiliar parts of the system rather than waiting to be assigned to your comfort zone.

Agile mindset with prior experience working in iterative, collaborative delivery teams.