Senior Elixir Engineer

About the role

Hack The Box is looking for a Senior Elixir Engineer to join a 7-person team reporting to the VP of Artificial Intelligence. The team works with product, design and security researchers to turn complex detection and response workflows into intuitive, intelligence-driven user experiences, while mentoring engineers and shaping the technical roadmap. The role is based in Europe/Greece, either fully remote or in the Athens Tech Hub.

Key responsibilities

• Design and build production Phoenix applications: REST APIs, LiveView UIs and real-time features on PubSub and Channels.
• Model and evolve data with Ecto and PostgreSQL, writing performant queries and safe, zero-downtime migrations.
• Build fault-tolerant systems with OTP: supervision trees, GenServers and distributed BEAM patterns.
• Own background processing and scheduled workloads with Oban, with observability via Telemetry and metrics.
• Ship secure-by-default code: authentication/authorization patterns, least-privilege data access and input hardening.
• Deploy and operate services on Kubernetes/GCP, contributing to CI/CD pipelines and release quality.
• Mentor engineers and contribute to technical leadership through code reviews, design sessions and coding standards.
• Document decisions and communicate clearly in a remote-first, async environment.

Required profile

• 5+ years of professional backend or full-stack development, with 3+ years shipping production Elixir/Phoenix.
• Strong grasp of OTP and the BEAM, including processes, supervision, GenServer/GenStage.
• Hands-on experience with Phoenix LiveView components, streams and JS hooks.
• Experience with background job systems (Oban preferred) and event-driven architectures.
• Solid testing discipline with ExUnit, including property-based and integration testing.
• Familiarity with containerized deployment (Docker, Kubernetes) and CI/CD best practices.
• Security-minded engineering: OWASP fundamentals, auth patterns and secure handling of user data.
• Excellent written and verbal communication, with a bias toward documenting architecture and decisions.

Required skills

• Elixir / Erlang / OTP
• Phoenix, Phoenix LiveView, Phoenix PubSub
• Ecto and PostgreSQL
• Oban, Tailwind CSS, Telemetry, Prometheus, Grafana, Sentry
• Docker, Kubernetes, GCP

What we offer

• Relocation support, including a 10% relocation bonus on annual salary and a 50% income tax reduction in Greece, plus accommodation during the first few weeks.
• 25 annual leave days and paid parental leave.
• Home office allowance and a dedicated budget for training and conferences.
• Full access to the Hack The Box lab offerings and flexible working hours.