Senior Backend Engineer (f/m/x)

Department: Development

Employment Type: Permanent employee

Schedule: Full-time

Seniority: Experienced

Location: Hamburg

This is a company built for growth.

At exmox, you’ll work on real systems on a big scale. We build high-performing consumer products used by millions of users, operating in a highly competitive, global mobile gaming ecosystem.

Our products are data-driven by design - powered by event-driven architectures, complex business logic, and fast feedback loops. Decisions are informed by data, experimentation, and measurable impact, not gut feeling.

We’re scaling fast and building one of the most exciting innovations in mobile gaming: rewarded user acquisition. That means distributed systems, evolving architectures, and problems that don’t have textbook answers.

As Senior Backend Engineer (f/m/x) you won’t just be “coding tickets” or maintaining legacy systems. We look for people with an engineering mindset and entrepreneurial ownership - you build it, you own it. You’ll work close to product and data, take responsibility for what you ship, and see the impact of your work in production.

If you’re excited by complex systems, high traffic, data-driven decisions, and the chance to grow by solving challenging problems, we want to hear from you.

• System architecture & backend engineering
  You architect and build high-scale backend systems that power real-time decision-making, ad delivery, and performance tracking. You ensure systems are reliable, maintainable, and scalable under high traffic, applying best practices in distributed systems, queues, and event-driven architectures.

• API design & integration
  You design efficient APIs and services that serve internal teams and external partners with low latency and high reliability, including REST and GraphQL endpoints. You integrate with third-party platforms, MMPs, and analytics tools to maximize campaign effectiveness.

• Performance, scaling & observability
  You ensure high performance under load using profiling, caching strategies, and horizontal scaling. You contribute to containerized deployments and observability with Docker, Kubernetes, and modern monitoring stacks to maintain system reliability and visibility.

• Mentorship & technical leadership
   You mentor and guide engineers through complex technical challenges, architecture reviews, and clean, scalable design. You foster a culture of technical excellence, collaboration, and outcome-driven engineering.

• Cross-functional impact
  You collaborate with product and data teams to deliver features that directly influence campaign effectiveness and advertiser ROI. Your work drives measurable business outcomes and sets the bar for system performance and reliability.

• Proven backend expertise
  5+ years of backend engineering experience, with at least 2+ in high-volume, data-rich environments. Strong Python expertise, with production experience in FastAPI, Flask, or similar frameworks.

• API & distributed systems knowledge
  Deep understanding of API design and backend system integration, including REST and GraphQL. Experience with distributed systems, queues (Kafka, RabbitMQ), and event-driven architectures.

• Performance & scaling focus
  Strong performance tuning and scaling skills, particularly for latency-sensitive, high-throughput systems. You think in systems and optimize holistically for efficiency and reliability.

• Cloud & container experience
  Experience with Docker, Kubernetes, and cloud infrastructure, ensuring smooth deployment, orchestration, and observability.

• Analytical & business-aware mindset
  You solve problems holistically, understand system-wide impacts, and make decisions that balance technical excellence with business outcomes.

• Communication & collaboration
  Strong communicator, comfortable explaining complex technical concepts to cross-functional teams, product managers, and business stakeholders.

• AdTech familiarity
  Experience with ad serving logic, tracking systems, fraud prevention, or real-time bidding is a significant advantage.

• Ambitious people, real ownership. You’ll work with driven, entrepreneurial people who care deeply about what they deliver, challenge each other openly, and own outcomes together.

• We’re playing at the top, but we’re not done. Our apps rank in the top 5 of their categories. We’re determined to push further, compete harder, and earn the number one spot.

• You own your own growth. Growth doesn’t happen by accident. At exmox, learning is built into the work - through responsibility, feedback, and real challenges. 

• Perks that help you focus on what matters. Transport subsidy, learning budget, wellness and gym, workation, bi-weekly team lunches, and more. The perks are great - but the real reason people join and stay is the challenge, the people, and the drive to win together.