Senior Elixir Engineer

Ready to embark on the quest of joining Hack The Box?

Welcome! Super excited you dropped by

At the end of this journey, you'll become a proud member of Hack The Box, with the ultimate mission to raise cyber resilience, so that every organization can stay ahead of tomorrow’s threats.

The core mission of the Senior Elixir Engineer:

Join our fast-growing team building the platform that trains the world's cyber workforce. As a Senior Elixir Engineer, you'll own backend and full-stack feature delivery on Phoenix and LiveView - designing resilient OTP systems, clean APIs, and real-time user experiences that scale to millions of users.

Our culture prizes autonomy, technical craft, and the drive to ship secure software that outsmarts attackers.

The fellowship you’ll be joining:

Reporting to the VP of Artificial Intelligence, you will be part of a 7 people team. You'll collaborate with product, design, and security researchers to turn complex detection and response workflows into intuitive, intelligence-driven user experiences-while mentoring engineers and shaping our technical roadmap.

Location & Work Mode:

• Europe/Greece

• Choose between fully remote work across Europe or relocating to our Athens Tech Hub with relocation support.

Fully Remote / Hybrid (2 days in the office, 3 days remote, plus one month of work from anywhere) - If only in Greece: When hiring in Greece, we’re open to candidates from all locations. Those based within 55 km of our Athens office will follow a hybrid work model. For candidates located beyond that radius, a fully remote arrangement is available.

Relocation

• We offer a 10% relocation bonus on the annual salary to support your move.
• In addition, you would benefit from a 50% tax reduction on your income as part of the relocation.
• We'll support you with accommodation during the first few weeks

Technology tools & weapons you’ll be using:

• Elixir / Erlang / OTP
• Phoenix, Phoenix LiveView, Phoenix PubSub
• Ecto & PostgreSQL
• Oban (background jobs)
• Tailwind CSS, LiveView JS hooks
• Telemetry, Prometheus, Grafana, Sentry
• Docker, Kubernetes, GCP

The adventures that await you after becoming Senior Elixir Engineer at Hack The Box:

• 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 where they earn their keep.
• Own background processing and scheduled workloads with Oban, with proper observability via Telemetry and metrics.
• Ship secure-by-default code: authentication/authorization patterns, least-privilege data access, and input hardening - this is a security company.
• 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 environment, contributing to a culture of thoughtful async collaboration.

Skills, knowledge, and experience points required to unlock the role of Senior Elixir Engineer at Hack The Box:

• 5+ years of professional backend or full-stack development, with 3+ years shipping production Elixir/Phoenix.
• Strong grasp of OTP and the BEAM - processes, supervision, GenServer/GenStage, and when not to reach for them.
• Hands-on experience building interactive UIs with Phoenix LiveView (components, streams, JS hooks).
• Deep Ecto and PostgreSQL knowledge: schema design, query optimization, indexing, migrations.
• Experience with background job systems (Oban preferred) and event-driven architectures.
• Solid testing discipline with ExUnit; comfortable with property-based and integration testing.
• Familiarity with containerized deployment (Docker, Kubernetes) and CI/CD best practices.
• Security-minded engineering: OWASP fundamentals, auth patterns, secure handling of user data.
• Excellent written & verbal communication, especially in remote/async environments, with a bias toward documenting architecture and decisions.

What your Hack The Box adventure will have in store:

• You'll have the exhilarating opportunity to contribute to a product that is highly appreciated by users and the cybersecurity community at large.
• You'll experience a highly supportive and caring environment, fostering growth, flexibility, and autonomy.
• You'll embark on an exciting journey of continuous learning and problem-solving, levelling up as our organisation grows.
• Most importantly, you'll have a blast at HTB because fun is an essential ingredient in our recipe for success! Just wait until you see our global meet-ups!

The gems you’ll be enjoying as Senior Elixir Engineer:

• 25 annual leave days
• Paid parental leave
• Home Office Allowance
• Dedicated budget for training and professional development, participation in conferences
• State-of-the-art equipment
• Full access to the Hack The Box lab offerings; so you can learn how to hack
• Flexibility in working hours

Our benefits package is designed to provide strong support to our team, but it may vary depending on location and type of employment (e.g., UK, US, Greece, Australia, or engagement through an Employer of Record or contract).

The Quest of Becoming Hack The Box’s Senior Elixir Engineer:

• Level 1: To complete level one’s objective, submit your application.
• Level 2: Meet the Talent Acquisition team. Level’s objective: highlight your past achievements, ambitions, and values.
• Level 3: Meet the hiring team. Level’s objective: have a technical conversation that aligns with day-to-day job-related tasks and responsibilities.
• Level 4: Level's objective: connect with the hiring team and share with them your achievements.
• Level 5: Congratulations! Not many reach this level . Level’s objective: have a constructive, final conversation with senior leadership to explore the role and your future at HTB.
• Level 6: You've officially received an offer from HTB! To complete the last level and the Quest, all you need to do is accept the offer.
• Quest complete. Congratulations, you’re officially one of us Your next quest: complete the onboarding.

Hack Your Career, Today. Join us in this epic adventure of cybersecurity at Hack The Box!

At Hack The Box, we are on a quest to find the most exceptional and enthusiastic talent to join our team. Whether or not you consider yourself a gamer, we value what makes you unique and want to know more about you. This job post provides just a glimpse of the incredible gamified experience our business and consumer customers enjoy through our platforms. So, if you're ready to embark on a journey of growth and adventure, we can't wait to meet you!

ABOUT HTB:

Hack The Box is the leading cyber readiness platform for the agentic era, battle-testing and upskilling both humans and AI agents to enhance organizational cyber resilience. Trusted by the Fortune 500, government agencies, and MSSPs, the platform delivers threat-informed learning paths consisting of real-world scenarios in gamified labs and live-fire simulations that build and validate offensive and defensive cyber capabilities. With a loyal community of more than 4 million members and 800+ enterprise customers, Hack The Box empowers teams and intelligent systems alike to strengthen cyber defenses and reduce breach risk effectively.

Rapidly growing its international footprint and reach, Hack The Box is headquartered in the UK, with additional offices in the US, Australia, and Greece.

News & Resources:

• We’re incredibly proud to share that our headquarters in the UK, along with our entities in Greece and the US, have been certified as a Great Place to Work for 4 consecutive years (2023 - 2026).
• In addition, our Greek entity has been recognized among the Best Workplaces in Greece (4th, 2nd, 3rd, 1st) and Europe (7th, 10th, 73rd) during this period - a testament to our strong culture and commitment to creating an exceptional employee experience!

Take a sneak peek at how it is to be part of HTB. Get more insights about our HTB culture and employee experience by visiting the “about us ” section of our site, our career site, and Glassdoor.

At Hack The Box, we are committed to fostering a diverse, inclusive, and equitable workplace. We believe that diversity enriches our performance, services, and the communities we serve. As such, we ensure that all job applications are considered solely based on merit, skills, and qualifications. We do not discriminate on grounds of race, color, religion, gender, gender identity or expression, sexual orientation, national origin, genetics, disability, age, or veteran status. We are dedicated to providing a fair and respectful work environment that reflects our values.