Senior R&D Engineer

Our client - a new Silicon Valley based profitable B2C product startup building innovative mobile solutions for the planet, is now looking for a Senior R&D Engineer

Type: Remote, full-time
Start date: ASAP
About project and role:

The product VPN - Super Unlimited Proxy is a Virtual Private Network that provides users online privacy and anonymity by creating a private network from a public internet connection.

The company has over 44M MAUs (and growing) with a solid customer base in the US and worldwide. In iOS, Out of the top markets we track worldwide, upon searching for the keyword VPN in the App Store, they are the #1 product in 32 out of 40 countries follow (including in the US, all of Western Europe, etc.) and in the top 3 for all 40 countries. In addition, they have been consistently ranked in the top 10 productivity apps in the US, right up with Google Docs, Google Sheets, etc.
The product has >1.6M very high-quality ratings in iOS alone.

We are hiring our first external R&D Engineer to join a small, focused team. You will work across the full stack of our VPN technology, from protocol integration and custom server tooling through to building the technical capabilities that directly drive the business forward.
This is not a maintenance role. You will be building new things: custom VPN tooling, integrating emerging protocols, and developing the technology that enables Super Unlimited to differentiate its product and grow its subscriber base. You will ship code that matters to the business.

Responsibilities:

• Build custom VPN tooling and services that power our server infrastructure
• Integrate new and emerging VPN protocols into our platform
• Develop internal tools and technology stacks that the business uses to create new product features and drive subscriber growth
• Write production-quality code in Python, Rust, Go, or similar for infrastructure services and tooling
• Work on server builds, provisioning pipelines, and deployment automation for a globally distributed network
• Harden and secure server infrastructure. Security is not an afterthought here
• Tune Linux systems and networking for performance and reliability
• Lead technical research and prototyping for new capabilities
• Help shape engineering culture and practices as the team grows
• Use and evaluate AI tooling as part of the development workflow — we use it across coding, code review, and research

Requirements:

• Proficiency in at least one of: Python, Rust, Go You write code daily, not occasionally
• Strong Linux knowledge (you are comfortable navigating the kernel, networking stack, and systemd without hand-holding)
• Solid understanding of networking fundamentals (TCP/IP, DNS, TLS, routing)
• Familiarity with VPN technologies or tunnelling protocols (WireGuard, OpenVPN, IPsec, or similar)
• Experience building tools, services, or automation, not just consuming them
• A security-conscious approach to everything you build
• Ability to work independently in a small team with minimal process, you identify what needs doing and do it
• Track record of shipping software that solved real problems
• Fluent in English (Upper-Intermediate or above)

Highly Valued:

• Experience with cryptography or TLS (key management, certificate infrastructure, protocol internals)
• Experience building or customising Linux distributions or server images
• Familiarity with infrastructure-as-code (Ansible, Terraform, or similar)
• Monitoring and observability experience (Prometheus, Grafana, time series databases)
• Experience shipping tools or features that directly impacted a product or business metric
• Contributions to open-source projects in the networking, security, or systems space

Why Join:

• Fast-Paced, Innovative Environment: Be part of a fast-growing company in the digital privacy and connectivity space.
• Remote Work: Enjoy the flexibility of working from anywhere.
• Collaborative Culture: Work with a passionate, creative, and motivated team that values ownership, experimentation, and results. Small team, high autonomy, real ownership
• Work on privacy and security technology that people actually use
• Direct line between what you build and business outcomes
• Influence over technical direction and engineering culture from day one