Backend Developer

Backend Developer

Cyprus or Remote Engineering

Hal Leonard is the world's largest print music publisher. Hal Leonard Connect is the platform that lets music retailers and partners worldwide sell Hal Leonard's digital sheet music, audio and media directly in their own stores. Behind it sits our billing system, which finance and analytics teams across Muse Group rely on as the source of truth.

We're looking for a senior backend engineer to take full ownership of both. You'll run a live B2B product with real external customers: you'll build it, keep it healthy, talk to the partners who use it, and shape where it goes next.

AI and automation are already part of how we work. We're looking for someone who uses them to work smarter, and who builds tools that let teammates help themselves. What's in it for you?

• A product that's truly yours. Two business-critical systems, direct contact with partners, and a say in the roadmap
• Real-world impact. Your work powers how millions of musicians get sheet music and audio from their favorite stores
• AI-first engineering. Tools, skills and automation are part of the job.
• Work from anywhere or join us in Cyprus

Key Responsibilities

• Own the Hal Leonard Connect backend (PHP / Yii2, MySQL): Catalog and Purchase API, vendor dashboard and admin, SDKs, rate limits, monitoring and alerts (Grafana, #hl-connect-allert), releases and crons
• Own Hal Leonard Connect integrations: Hal Leonard AS400 (vendor registration, transactions, invoices), Perfion (HLE catalog), DAM, Keycloak / auth, Stripe
• Vendor asset access rules, multi-currency, order processing, data quality (Oracle ↔ HL Connect vendor discrepancies)
• Own the Stripe-based billing system: new Stripe accounts and products (MuseHub, EEMC, HL Permissions), alerts, finance and analyst data requests, Metabase dashboards
• Be the technical contact for Hal Leonard staff and external vendors: onboarding, instructions, FAQ and docs, hlconnect.slack.com, Jira BS tickets, review of partner-facing emails
• Represent engineering in HL Connect Sync, Sales HL Connect Europe / US and Sublicensing meetings; turn sales requests (e.g. Shopify) into scoped roadmap items
• Build tooling and skills that let HL editors, sales and finance self-serve instead of going through an engineer
• Code review and knowledge sharing in the backend horizontal (SMP, UG, sub-licensing)

Required Experience

Must have

• 5+ years of backend development in PHP (Yii2) with MySQL in production
• Designed and operated a public REST API for external developers: versioning, SDKs, rate limits, documentation, backward compatibility
• Integrations with third-party and legacy systems: ERP / PIM, SOAP / XML, file-based imports, data reconciliation;
• Payments: Stripe (webhooks, invoices, payouts, multiple accounts), reconciliation, writing money-safe code
• Operating your own service end-to-end: Docker / Kubernetes, crons, Grafana / Prometheus, Sentry, incident ownership for your service
• SQL and analytics: builds Metabase dashboards and answers finance / analyst questions with data
• AI-native engineering: daily use of Claude Code, Cursor or similar for development, tests and documentation; has built tooling or skills for non-engineers
• Written English B2+: daily correspondence with Hal Leonard staff and external vendors, explaining a REST API to non-technical people, writing docs and FAQ
• Self-directed: comfortable being the single owner of a product with external customers

Nice to have

• Keycloak / OAuth, ClickHouse, Zendesk apps, Shopify apps
• Music publishing / sheet music domain, royalties, sub-licensing

Muse Group Empowers Music Makers

We create the world's most popular apps for playing, recording and composing music. Through our innovative learning tools, expansive music catalogs and free open-source software, we make it easier for millions — from beginners to experienced musicians — to be creative every day. Our talented team of music lovers collaborates all over the globe, from Limassol to Seoul and Boston to Berlin.

We're an ambitious company with the drive and culture of a startup — with many more exciting Muse Group developments to come. Hal Leonard, which joined Muse Group in 2023, is the world leader in sheet music publishing and music education. The company has a storied history of providing music learners with the very best methods and arrangements of popular music for over 70 years. Hal Leonard is also a major distributor of popular brands of instruments, gear, and software to the music trade worldwide.