Principal Engineer

The ground beneath their feet is the factor no one has to remember. The factor no one has to stop to use. The factor no one can fake.

You cannot be in two places at once, but every digital signal that claims to prove that fact is being manipulated. GPS spoofs with a one-click app. IP addresses yield to any VPN. Credentials get phished. 2FA gets bypassed. AI fabricates voices and faces at scale. The digital is cheap and easy to manipulate. Physical reality is entirely different.

Our mission is to make physical presence cryptographically verifiable, anchoring digital actions to physical reality. The mission is not better GPS. It's the return of the real, the new primitive for verifying the ground beneath our feet.

This is a foundational role. You will build alongside the founders at the nexus of sensor fusion, on-device ML, and programmable cryptography. Your code will define the architecture and performance of the Octet SDK, the mobile app, and the proof pipeline - directly translating the company's strategy into production-ready systems.

Success requires high agency and unwavering commitment to building global, unbreakable infrastructure from the ground up. Competitive compensation. Work from the office in London with the CEO and help to build an extraordinary team.

About Octet

Every digital transaction has a physical layer. Someone is always somewhere when they tap, approve, or transfer. That somewhere is the only signal that can't be fabricated. But when transactions went digital, the global economy lost the ability to verify physical reality. $23T across payments, insurance, and logistics now moves without any way to verify where money is received, where transactions originate, or where actions actually occur.

Octet makes that physical layer verifiable. We built alt-GPS technology deployed today with elite military units — adversarial environments where GPS is jammed and spoofed and location absolutely cannot fail. Now we're building the commercial SDK: on-device ML that cross-references raw sensor data (accelerometer, gyroscope) against signals of opportunity and geospatial models, bound to hardware-backed keys.

Octet models the four-dimensional structure of the real world — three spatial dimensions plus time — from sensors already inside the device. The output is not a coordinate. It is a cryptographic proof that a specific device occupied a specific volume of space at a specific moment.

We remove surveillance; no raw coordinates leave the device, no tracking infrastructure, no centralized location database. We also peel away the layers of friction that force 52% of consumers to abandon any verification process that's longer than 10 minutes. Policy evaluation happens locally; the proof reveals only a binary answer to a specific question (inside geofence?) without exposing actual position. Customers get a simple, strong answer. Individuals retain the sensitive history of where they've been.

The founders are repeat venture-backed and have worked together for a decade: CEO Benjamin Fels (ex-derivatives trader, built AI systems for financial markets and supply chains), COO Drew Arenth (edge tech and logistics), CTO Suvrit Sra (MIT and TUM Professor, €5M Humboldt Prize for AI). Backed by Variant, ex/ante, hivemind and world-class angel investors.

Why now?

Money has followed a clear pattern: add a new kind of physical presence and remove both friction and risk. * You sign the check. The signature proves you authorized it. * You swipe. The card proves you're the account holder. * You tap. Hardware-bound proof the physical card is present - and the signature line disappeared. Fraud dropped. No extra steps for the user. Each breakthrough gave the system a new way to read physical reality. Then transactions went digital and the physical layer disappeared. The result is another password, another 2FA, another face scan — and fraud that now rivals the third largest economy on earth in scale, growing faster than global GDP.

Responsibilities

Core Engineering & Architecture (primary emphasis):

• Architectural Leadership: Be the driving force behind the design and build of the high-integrity, low-latency architecture for the Octet SDK and the associated proof pipeline. Android is the current priority; iOS is on the roadmap.

• On-Device ML: Advance and implement on-device ML models that convert multimodal sensor data - and signals of opportunity - into verified, real-time proofs of presence.

• Cryptography Primitive: Drive the strategy and implementation of zero-knowledge architecture to achieve privacy-preserving verification without compromising performance or battery life.

• Scalability: Architect developer APIs, telemetry pipelines, and usage-based proof metering.

• Privacy: Ensure all computation adheres to Octet’s core privacy-by-design mandate

Product & Release Delivery:

• Ship Fast and Often: Be the key technical driver for the first major SDK releases, directly enabling our go-to-market in payments.

• Roadmapping: Translate market insight and research breakthroughs into concrete, aligned engineering roadmaps for rapid iteration and deployment.

Technical Leadership & Collaboration:

• Authority: Act as the senior-most IC, setting the gold standard for low-level systems programming, code quality, security, and on-device performance.

• Research-to-Product: Partner with our scientific advisors (MIT, TU Munich) to rapidly transition cutting-edge research into practical, production-ready systems.

• Team Building: Mentor and provide technical guidance to early hires, shaping the culture of a high-performing engineering team.

Systems Reliability & Integrity:

• Hardened Baselines: Establish robust, repeatable baselines and validation pipelines using real-world motion data and adversarial conditions (jamming, spoofing attempts).

• Global Performance: Ensure the Octet SDK performs reliably and consistently across diverse hardware, sensor quality, and global geographies.

• Continuous Improvement: Architect integrity scoring and motion-validation mechanisms that continuously improve the model with every verified event.

Qualifications

5+ years of experience in two or more of the following areas:

• Spatio-Temporal Systems: Experience with inertial sensors, sensor fusion, and real-time data from autonomous systems or robotics.

• On-Device ML / Edge Compute: Expertise in deploying high-performance, resource-constrained ML models on mobile or embedded systems.

• Low-Latency SDK Development: Proven track record building and shipping high-reliability, low-latency mobile SDKs on Android or iOS.

• Mobile Platform Mastery: Fluency in Android or iOS development at the systems level - sensor APIs, background execution models, power management, and platform-specific constraints. Willingness to work across both platforms.

• Signal Processing: Deep understanding of noise modeling, physics-informed inference, and error-correction techniques.

• Bonus: Experience with privacy-preserving architectures (e.g., Homomorphic Encryption, Secure Enclaves) or programmable cryptography (ZKPs).

Leadership & Execution:

• 0→1 track record: Proven ability to execute complex, undefined engineering programs in a fast-paced, high-agency startup environment.

• From arXiv to the outside world: Demonstrated success in taking cutting-edge research and hardening it into resilient, production-grade systems.

• Founder Mindset: Rapid iteration, hands-on problem solving, and a profound sense of ownership over the entire technical stack

Credentials are stolen. Faces are synthesised. Location pings are spoofed. Every signal the global economy relies on to verify action is compromised. Physical presence at a specific place, at a specific time, is the one thing that cannot be faked. No one has yet made it programmable. Join us in building the new primitive.