Senior Backend Developer (mwd)

Senior Backend Developer (mwd) New Soul•Berlin, Berlin, Germany

Help us revolutionize the massage industry in Germany.

At New Soul were redefining modern wellness by blending premium in-studio experiences with a strong digital platform that powers booking payments memberships and daily studio operations. As we scale across Germany system stability performance and clean integrations are business-critical what we ship directly affects revenue operational load and customer experience.
We run a lean team with high ownership minimal meetings and a pragmatic engineering culture: ship impact keep things maintainable avoid over‑engineering and document just enough so others can move fast with confidence.

Your Role

As a Senior Backend Developer youll build and evolve our backend systems and integrations that support both customer-facing journeys (booking payments memberships) and internal operational tooling. Youll work closely with Product Frontend and Ops stakeholders to deliver scalable features improve reliability and reduce operational friction.
This is a great fit for someone who can operate independently handle ambiguity and drive work end-to-end from understanding the problem to shipping the solution and leaving the system cleaner than before.

Your Responsibilities

• Build and maintain backend services that power core platform capabilities (e.g. booking availability memberships payments logic operational workflows).
• Design implement and evolve internal and external APIs (GraphQL/REST) ensuring consistency performance and long-term maintainability.
• Own technical execution for complex projects with unclear dependencies align early de‑risk quickly deliver steadily.
• Proactively identify bottlenecks failure points and technical debt; propose pragmatic fixes and execute them.
• Create proof‑of‑concepts (POCs) where needed to validate approaches before implementation.
• Collaborate closely with frontend engineers product and operations teams to ensure smooth end-to-end delivery.

Your Tasks

• Initiate and maintain lightweight but useful technical documentation:
• API documentation (e.g. Swagger )
• Infrastructure and Component Diagrams (at a level less detailed than L4 but more comprehensive than nothing).
• Improve and operate within a custom / minimal‑framework environment focusing on incremental improvements and clarity rather than relying on heavy frameworks as Symfony.
• Take ownership of delivery for multiple parallel initiatives balancing urgency with quality.

Requirements

Must-Have Skills

• 5 years of professional experience with PHP with continued interest in its application.
• A self-organized technically skilled individual who avoids over‑engineering solutions.
• Advanced stage of growth in understanding the balance of complexity vs. simplicity (e.g. past the valley of despair on the Dunning‑Kruger effect curve).
• Proficient in integrating and building internal and external APIs.
• Experienced in starting projects from scratch with strong architectural design skills.
• Comfortable joining a project as an Individual Contributor (IC) rather than enhancing an existing system gradually.
• Capable of independently managing and delivering tasks systems and contributions that align with team goals.
• Strong communication skills with a results‑oriented and efficiency-driven mindset.
• Proficient English speaking German is a plus

Nice-to-Have Skills

• Experience with other languages (especially Golang).
• Basic DevOps knowledge (Kubernetes Terraform) and comfort working with infra‑adjacent topics.

Tech-Stack

• Core Frameworks and Libraries: In-house Framework
• Languages and Tools: PHP8 MySQL Redis (Equivalents) RMQ/Kafka Kubernetes
• Testing Frameworks: PHPUnit
• APIs and Integrations: GraphQL REST APIs OpenAPI
• Version Control and CI/CD: Git Github Actions

What Youll Get

• Real ownership and impact: Your work directly improves customer experience and studio operations and is used by thousands of customers across Germany.
• Pragmatic engineering culture: High trust Flexible working hours Minimal mandatory meetings.
• Engineers get a top‑spec laptop using the platform of their choosing.
• The choice of a range of Company Benefits (50% of all products and services) Urban Sports Club membership and coverage of Deutschland‑Ticket.
• An office centrally located in Berlins beautiful Kollwitzkiez.

If you want to build reliable systems that power a real‑world product and work with a team that values clarity ownership and smart simplicity wed love to hear from you.

Apply now!