Sr Software Engineer - B/E

Rebuy, Inc.

6d•$130,000 - $180,000•Remote

About The Position

At Rebuy, we’re on a mission to revolutionize shopping with intelligent, personalized experiences that wow customers around the globe. As a fully remote team, we power some of the fastest-growing DTC brands like Aviator Nation, Liquid Death, Magic Spoon, Blenders, Laird Superfoods, Primal Kitchen, and many more. We believe in ownership, drive, and empathy, and strongly uphold that every team member plays a vital role in shaping the future of intelligent commerce. Our culture thrives on collaboration, creativity, and genuine passion. We don’t just build great tech - we build lasting partnerships, a strong community, and a place where people love to work. Rebuy and its team members continually strive to create a high-spirited, intentional work environment that stresses performance, productivity, collaboration, and merit. As a Sr. Software Engineer, Back-End, you’ll own some of the most consequential systems at Rebuy. Your primary anchor is our billing and payments infrastructure — the engine that determines how merchants are charged, how partners get paid, and how financial balances flow across our entire product suite. This is genuinely complex financial engineering. It requires deep PHP and Go expertise, careful architecture, and judgment that no automated tool can replicate. Merchant billing runs daily, touches real revenue, and demands someone who understands both the technical and business dimensions of every decision. Alongside billing, you’ll grow into a broader platform portfolio — the partner portal, data ETL pipelines, customer-facing APIs, and reporting infrastructure that power the business. And in the near term, you’ll play a critical role in a significant technical migration: moving our legacy Code Igniter 2 codebase to Code Igniter 4, including work tied to increasing our enterprise market share. This migration requires hands-on PHP expertise and cannot be deferred. You won’t be handed a sprawling list of things you must do on day one. You’ll be trusted to grow into this role — and rewarded when you do.

Requirements

Experience building or maintaining billing, payments, or financial systems — including working with payment processors, subscription engines, invoicing pipelines, or similar financial infrastructure in a production SaaS environment.
Educational background in CS // Engineering or a similar area.
5+ years of hands-on experience building backend applications with PHP and Go, with a proven track record of delivering complex, high-traffic systems.
Experience designing and implementing secure, scalable, and maintainable RESTful APIs in PHP and Go, with a deep understanding of API design patterns, versioning, and performance optimization.
Experience with cloud-based technologies, preferably GCP.
Strong understanding of a performant SaaS environment.
Experience in a Scrum/Agile environment.
Experience with the Atlassian suite, including Jira and Bitbucket.
Solid understanding of security fundamentals as they apply to backend and financial systems — including secure coding practices, authentication/authorization patterns, data encryption, and awareness of current vulnerability trends (e.g. OWASP Top 10)
A collaborative mindset and work approach with the ability to lead projects and mentor others.
The ability to thrive in a fast-paced environment with a high level of autonomy and responsibilities.
Excellent communication skills, especially being able to explain technical concepts to both technical and non-technical audiences.
Genuinely curious about the intersection of engineering and business. You care about the downstream impact of what you build — not just that the code works, but that it moves the company forward.

Responsibilities

Billing & Payments Architecture: Design and build Rebuy’s centralized billing system that handles merchant billing, partner payments, and customer-facing charges. Architect the integration layer that allows payment balances to be applied across Rebuy’s full suite of services. Tackle genuinely complex financial engineering challenges with PHP and Go at scale.
Build Robust APIs: Design and implement secure, well-structured APIs in PHP and Go to power billing events, payment processing, and financial data flows across our platform and Shopify integrations.
Legacy Modernization: Lead and contribute to the migration of our Code Igniter 2 codebase to Code Igniter 4. This is high-priority, near-term work with real business dependencies — including enterprise partnership commitments — and requires a PHP engineer with the experience and judgment to do it right.
Agentify the Platform: Partner with product and engineering to identify where AI agents can automate workflows, surface insights, and guide merchants through our product. Build the backend systems — APIs, data pipelines, and event hooks — that enable intelligent automation. This is genuinely new territory and one of the most exciting growth vectors for Rebuy’s product.
Platform Breadth: Our team owns more than billing and payments — we also support a partner portal, data ETL pipelines, customer-facing reporting APIs, and the infrastructure that makes data flow reliably across the business. You won’t be responsible for all of it on day one, but you’ll have genuine opportunities to grow into the areas that most interest you. Engineers here don’t get siloed; they get context.
Engineering Best Practices: Contribute significantly to the engineering culture at Rebuy by establishing, documenting, and promoting best practices. Lead initiatives to introduce and standardize frameworks and tools that increase development efficiency and maintainability.
Security & Compliance: Stay current with the latest security trends, vulnerabilities, and best practices as they apply to billing and payment systems. Champion security-first engineering across authentication, authorization, data encryption, and compliance considerations in everything you build.
PHP Technical Leadership: Serve as a key technical anchor for PHP across the engineering organization. Rebuy’s codebase has significant PHP depth and relatively few engineers with that expertise. You’ll lead code reviews, share knowledge actively, and help raise the PHP competency of the broader team.
Quality Assurance: Conduct quality checks on deliverables to ensure code, setup, and configurations meet expected results. Ensure that all features meet high standards of quality and performance before deployment.
Team Collaboration: Engage actively in building a strong team culture. Work closely with the Product Owner, Engineering Manager, and peers across billing, payments, partner tools, and data infrastructure to define requirements, estimate effort, and drive solutions forward. This is a team where your voice matters — you won’t just be handed tickets. Assist the Support team in triaging and resolving high-priority production issues.

Benefits

Team: We’ve got the best, brightest, most brilliant team members who are excited to meet you! We also like to think we have a good sense of humor.
Remote Work: With a strong internet connection, you’re able to work from anywhere within the U.S. and Canada.
PTO: We offer a flexible vacation policy, generous holiday schedule, parental leave and sick policy. There’s other policies too like a birthday holiday!
Amazing Benefits: 100% free health, dental, and insurance for you and your family. Don’t worry, there’s even more!
Retirement Plans: For our U.S. employees we offer 401(k) retirement plans and for our Canadian employees we offer a TFSA and RRSP retirement plans. You’ll also enjoy a 3% contribution of your gross salary, no matter where you’re located!

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