Backend Engineer (VPN)

Proton; Barcelona; Presencial; EUR 53.000 - 104.000; Jornada completa

Ventajas ofrecidas por este puesto de trabajo

Stock options

Health coverage

Retirement plans

Paid time off

Relocation support

Lunch & snacks

Descripción de la vacante

Proton in Barcelona is seeking a skilled Backend Engineer to help build the VPN backend that scales for millions of users while upholding privacy by default. You will collaborate with engineers, architects and product managers to deliver reliable services and robust APIs.

Bring hands-on PHP backend experience, SQL/MySQL, Redis, Docker and security focus. Familiarity with OpenAPI, observability tools like Grafana/OpenTelemetry, and on-call/SRE practices is a plus.

Formación

• Experience with PHP-based entry-points to a back-end software stack.
• Experience building scalable back-end solutions.
• Experience with profiling methods and tools.
• Experience leading a team initiative from discovery to production.
• Solid understanding of SQL (MySQL preferred) and data modelling.
• Solid understanding of Redis or other caching technologies.
• Solid understanding of security best practices.
• Solid understanding of HTTP/REST, including both developing and consuming Web-based APIs
• High-level understanding of cryptography concepts (key exchange, symmetric vs. asymmetric).
• Operational experience such as SRE or on-call.
• Experience with Docker or similar containerization technologies.
• Experience with Grafana and OpenTelemetry.
• Experience with Python and/or Rust.
• Experience with OpenAPI specs or other API documentation frameworks.

Responsabilidades

• Work with back-end engineers and architects to build scalable, reliable systems.
• Collaborate with client app teams and product management to meet reliability needs.
• Document back-end capabilities for Proton VPN clients.
• Debug and repair systems for file revisions and quota management.

Conocimientos

PHP backend

Scalable systems

Profiling

Team lead

SQL

Redis

Security practices

HTTP REST

Cryptography basics

SRE / On-call

Docker

Grafana

OpenTelemetry

OpenAPI

Python

Rust

Herramientas

MySQL

Grafana

OpenTelemetry

OpenAPI

Descripción del empleo

Sep 14, 2026

Join Proton and build a better internet where privacy is the default

Proton was founded in 2014 by scientists from CERN on a simple truth: privacy is a fundamental human right. Since then, we’ve built the world’s largest encrypted email service (Proton Mail) and expanded into Proton VPN, Proton Drive, Proton Pass, and Proton Calendar—tools used by millions globally to protect their freedom, fight censorship, and keep their data safe. In some situations, Proton has literally helped save lives!

We are profitable, independent (no VC control), and selectively hire from the top ~1% of applicants. Our 700+ team members across 50+ countries come from leading organizations and elite academic backgrounds. We move fast, keep hierarchy light, and prioritize impact over optics. If you want to do meaningful work with exceptionally high-caliber people, this is it. Join us and do work you can truly be proud of. Check our open-source projects here !

Purpose of the role:

The VPN team is focused on building the best and most trustworthy VPN in the world. We aim to provide the best user experience to millions of people around the world willing to take back their online privacy, while providing sophisticated technologies to bypass network restrictions in highly censored countries.

What you will do:

• Work closely with a group of Back-End Engineers and Architects to build resilient, massively-scalable solutions for millions of people to rely on
• Collaborate with teams of client application developers and product management to ensure that the back-end meets critical business and reliability requirements
• Document back-end capabilities and their proper use so that all Proton VPN clients can implement correctly-functioning solutions
• Debug and repair vital systems such as the systems responsible for cleaning up file revisions and returning quota to users

Job requirements:

• Experience with PHP-based entry-points to a back-end software stack
• Experience building scalable solutions
• Experience with profiling methods and tools
• Experience leading a team initiative from discovery to production
• Solid understanding of SQL (MySql preferred) and data modelling
• Solid understanding of Redis or other caching technologies
• Solid understanding of security best practices
• Solid understanding of HTTP/REST, including both developing and consuming Web-based APIs
• High-level understanding of cryptography concepts such as key exchange and the difference between symmetric and asymmetric encryption
• Operational experience such as SRE or on-call, demonstrating ability to diagnose and troubleshoot complex problems for critical systems
• Experience with Docker or similar containerization technologies
• Experience with metrics graphing/analysis toolkits such as Grafana and OpenTelemetry
• Experience with Python and/or Rust
• Experience with OpenAPI specs or other API documentation frameworks

Even if you don’t meet all the requirements listed above, but feel you could still be a great fit, please still apply.

What We Offer

• Work that Matters: millions of people trust Proton with their privacy. We answer only to our users — not advertisers, not investors with conflicting agendas, not governments. The work you do here is real, and the impact is measurable. (read more about our impact here )
• Stock Options: at Proton, we all have the opportunity to be owners of the company. From day one, you have a real stake in what we're building. When Proton wins, you win.
• Technology: you'll get the right hardware and the right software you need to do your best work.
• Learning & Development: we invest in your growth because sharp people make us better. Proton is one of the fastest ways to accelerate your career because you'll be thrown into real challenges, with real ownership, from day one.
• Employee Benefits: your wellbeing isn't an afterthought. We offer strong health coverage, solid retirement options, generous leave, and wellness support so you can bring your best self to work every day
• In-Person Collaboration: Amazing things happen when passionate, smart, and purposeful people get together in the same room. With offices across Geneva, Zürich, Barcelona, London and more, you'll spend most of your time collaborating face-to-face with people who genuinely care about what they're building
• Food: Lunch and snacks are on us every day in our offices so you can focus on the work and not on what's for lunch.
• Transport: getting to the office shouldn't cost you. We cover public transport, bike allowances, or parking, whichever works for you.
• Flexible Working: you own your schedule. Set hours that work for you and your team — because outcomes matter more than when the clock says you started.

Compensation range

• Barcelona: 53,000 - 104,000 EUR gross annually
• Other locations: Compensation will be discussed during the interview process
• Final compensation will be determined based on the candidate's qualifications, skills, and previous experience.

Our Commitment to Diversity and Inclusion

At Proton, we believe diversity drives innovation and strengthens our mission to provide privacy as a default for all. We are committed to fostering an inclusive environment where all individuals, regardless of race, ethnicity, gender, age, sexual orientation, physical ability, or socio-economic background, feel valued and empowered. We strive to create equal opportunities, promote open dialogue, and support continuous learning to ensure every voice is heard and respected.

If you need any extra support or reasonable adjustments during the hiring process, please let your talent partner know.

Candidate Privacy Notice

When you apply for a position, refer a candidate, or are considered for a role at Proton Technologies AG (Proton, we, us, or our), your information is stored in Greenhouse, in accordance with their Service Privacy Policy. This information is used to evaluate your suitability for the posted position. We also retain this information for consideration for future roles that you may apply for or that we believe may align with your background and skills.

If we no longer have a legitimate business need to process your information, we will either delete or anonymize it. Should you have any inquiries about how we use or manage your information, or if you wish to access, correct, or delete your data, please contact our privacy team at [e-mail].

Proton does not accept unsolicited resumes from any sources other than directly from candidates. We will not pay a fee for any placement resulting from an unsolicited offer, even if the candidate is subsequently hired by Proton.

A better internet starts with privacy and freedom

Proton is a community-driven organization providing secure, privacy-focused tools like email, VPN, calendar, and storage, trusted by over 100 million users globally.

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