Senior Backend Engineer (m/f/d)

Why this role matters

At JOIN, we believe hiring should be easy, fast, and fair – for companies and candidates alike. That’s why we’re building intuitive, powerful recruiting software that helps businesses of all sizes find the right people effortlessly.

As our Senior Backend Engineer, you’ll play a key role in shaping the architecture and reliability of JOIN’s core product - the multiposting platform that connects thousands of companies with millions of candidates across Europe. Your mission will be to design, develop, and scale backend systems that power our integrations with hundreds of job platforms. Sitting at the intersection of Product, Frontend, and Platform teams, your work will directly impact JOIN’s success and growth.

What you’ll be doing

Your work will directly influence how businesses hire through JOIN. Here’s what that looks like:

• Design, develop, and maintain scalable backend services in a microservice-oriented environment.
• Collaborate with frontend engineers, product managers, and DevOps/Platform teams to deliver impactful features through our Agile SDLC/Kanban process.
• Write clean, well-structured, and testable code using modern technologies like Node.js, TypeScript, GraphQL, and gRPC.
• Conduct peer code reviews, ensuring code quality and consistency across the team.
• Participate in technical retrospectives to discuss testing culture, architectural improvements, automation, and coding standards.
• Help define technical requirements and propose scalable solutions that align with team goals.
• Ensure the reliability, performance, and security of JOIN’s backend infrastructure.
• Continuously contribute to a culture of automation, testing, and knowledge sharing.

Who you’ll work with

You’ll collaborate closely with our Backend Guild, Product Managers, Frontend Engineers, and Platform/DevOps teams. Together, you’ll build reliable, high-performance systems that ensure JOIN’s customers and candidates enjoy a seamless experience.

What we’re looking for

We don’t believe in rigid checklists – but if most of these apply to you, we’d love to chat:

✔ 5+ years of backend development experience.
✔ 2+ years of experience working with a strongly typed language (TypeScript, Go, Java, etc.).
✔ Solid experience with relational databases (e.g. PostgreSQL, MySQL) and ORMs.
✔ Strong understanding of backend architecture, scalability, and performance optimisation.
✔ Good unit and integration testing experience (TDD preferred).
✔ Experience with message brokers (SNS, RabbitMQ, Kafka, Google Pub/Sub, etc.).
✔ Familiarity with CI/CD pipelines and cloud infrastructure (AWS, GCP, or similar).
✔ Proactive mindset with ownership of system reliability and quality.

Bonus points for:

• Experience with Node.js and GraphQL.
• Familiarity with gRPC and protocol buffers.
• Understanding of SOLID principles and Clean Architecture.
• Hands-on experience with Kubernetes.
• Previous experience in SaaS or HR Tech environments.

Our Values

❤️ People First – We put humans at the heart of hiring.

🚀 Own It – We take initiative and solve problems independently.

🛠 Work Smarter – Efficiency beats effort.

💡 Be Bold – Challenge the status quo and push boundaries.

At JOIN, we thrive in a fast-moving, collaborative environment, and we are looking for colleagues who do too. That means:

• We love collaborating in the office sharing knowledge with all colleagues, and we do understand the flexibility of working from home when needed
• We adapt quickly and embrace change in a growth-oriented startup environment
• We continuously challenge ourselves and each other to improve

This role might not be ideal if:

• You prefer a highly structured environment.
• You want a fully remote position.
• You prefer minimal change and a slower pace.
• You’re not excited about ownership and growth.

What’s in it for you?

🖥 Apple hardware – The best tools for the job (MacBook).

🏆 Team events – Brunches, sports activities, and quarterly gatherings in Berlin.

🌍 Productivity from Everywhere – 104 days per year remote (post-probation), following our hybrid policy.

🏦 Competitive salary – Tailored to align with your experience level.

🏠 Relocation support – Assistance with paperwork, travel, and one month of furnished accommodation.

What to expect from the hiring process

We respect your time and keep things transparent:

1️⃣ Intro call (~30 min) – Let’s see if we’re a good match.

2️⃣ Hiring Manager Review – Your profile is assessed for technical and team fit.

3️⃣ Hiring Manager Interview (~60 min) – Dive into expectations and team dynamics.

4️⃣ Technical Interview (~60–120 min) – Demonstrate your skills.

5️⃣ Meet the Team (Optional) – Connect with your future colleagues.

You’ll always know where you stand - no black holes, no ghosting.

We welcome applications from individuals of all ages, abilities, genders, religions and diverse backgrounds. If you need assistance during the hiring process or in the workplace, let us know!

Don’t meet every requirement? No problem! We’re always open to exceptional candidates and value diversity in all forms.

📩 Apply now – We’d love to connect with you!