Senior Backend Developer; mwd

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

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.

• 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 (Graph
  
  QL/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.

• 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.

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 Dev Ops knowledge (Kubernetes Terraform) and comfort working with infra‑adjacent topics.

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

• 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!