Senior Backend Engineer (SaaS/AI · Onsite · Şişli, İstanbul)

Apilex is building the infrastructure for how legal work gets done. Our platform is used by lawyers and legal teams across Turkey, Germany, and France, handling real casework, real documents, real deadlines. We are 80+ people, fully bootstrapped, and growing on product revenue alone. No investors setting our priorities. Just a hard problem, a strong product, and a team that ships.

We are hiring a Senior Backend Engineer to help us scale the systems behind a platform that is already live across three countries and growing fast.

• Design and develop high-traffic, scalable microservice architectures that can support a rapidly expanding user base across multiple markets.
• Own the quality of what gets shipped: lead code reviews, set standards, and be the kind of engineer whose feedback makes the whole team better.
• Work across a modern backend stack — real-time event streaming, full-text search, hybrid data architectures — and make decisions that hold up at scale.
• Provide technical mentorship within the team. You have seen things go wrong before, and you help others avoid those paths.
• Collaborate with the AI and product teams to integrate LLM-powered workflows reliably into production systems.

Must-have:

• 5+ years of backend experience with Java and Spring Boot, or similar JVM-based frameworks.
• Strong foundation in software architecture design, OOP, SOLID principles, and design patterns at various scales.
• Production experience with both NoSQL databases (MongoDB or similar) and relational databases (PostgreSQL or similar), with the ability to design hybrid data architectures.
• Strong knowledge of Elasticsearch or similar search and indexing technologies.
• Experience with messaging systems such as RabbitMQ or Kafka.
• Hands-on experience with Redis or similar in-memory caching solutions.
• Solid understanding of WebSocket and real-time streaming architectures.
• Hands-on experience with cloud platforms (AWS, Azure, or GCP) and CI/CD pipelines.

Nice-to-have:

• Experience integrating AI or LLM-based components into a production backend.
• Background in document-heavy or high-correctness domains: legal, compliance, finance, or similar.
• Experience with multi-language or multi-locale systems.

Apilex launched under a year ago. Since then, the team has grown to 80+ people across three countries, funded entirely by product revenue with no external investment. Turkey, Germany, and France are live. Brazil is next. The pace is fast and the standards are high — legal professionals depend on the platform daily and they notice when things break. You will be joining a team that is energetic, direct, and genuinely excited about what they are building. The office is in Bomonti, in the center of Istanbul. If you want to work on systems that are already at scale and still growing, we would like to talk.