Founding Engineer (Full Stack)

Harnham - Data and Analytics Recruitment; Greater London; Hybrid; GBP 85,000 - 115,000; Full time

Benefits offered by this job

Equity

Ownership stake

Job summary

Harnham - Data and Analytics Recruitment in London is seeking a Founding Full Stack Engineer to join early-stage tech and own core software from day one. You will work across mobile, cloud, and connected devices, shaping long-term strategy while building scalable systems.

You'll own mobile apps on iOS/Android, BLE connectivity, AWS-based cloud infrastructure, data pipelines, and AI-enabled features, with significant ownership and a clear path to technical leadership as the company scales.

Qualifications

• Founding software hire with ownership from day one.
• Experience shipping production software for consumer/enterprise products.
• Strong mobile app development experience (iOS/Android).

Responsibilities

• Build and maintain mobile applications across iOS and Android.
• Develop and optimise BLE connectivity between devices and apps.
• Design and manage AWS-based cloud infrastructure and backend services.
• Create scalable data ingestion and processing pipelines.
• Support integration of AI-enabled features into products.
• Own software quality, observability, deployment and release processes.
• Collaborate with product and engineering to translate requirements into production solutions.
• Contribute to growth and development of the software function as the business scales.

Skills

Mobile apps

BLE devices

AWS Cloud

Full stack

AI tools

Fast-paced work

Communication

Production software

Job description

Full Stack Engineer (Founding Engineer)

Hybrid London | £100,000+ Equity

This is a rare opportunity to join an early-stage technology business as a foundational software hire. You will have significant ownership from day one, working across mobile, cloud, and connected device technologies while helping shape the long-term software strategy and engineering function.

The Company

They are an innovative technology business developing connected products that combine hardware, software, and data to deliver meaningful real-world impact. Their product is already in market with a growing user base and a clear roadmap for future growth. The team is highly collaborative, technically strong, and focused on building solutions that genuinely improve customer outcomes. You will join at a pivotal stage, with the opportunity to influence both product direction and technical decisions.

The Role

You will take ownership of key software systems across mobile applications, cloud infrastructure, and device connectivity, working closely with senior stakeholders and technical teams.

Responsibilities include:

• Building and maintaining mobile applications across iOS and Android platforms.
• Developing and optimising Bluetooth Low Energy (BLE) connectivity between devices and applications.
• Designing and managing AWS-based cloud infrastructure and backend services.
• Creating scalable data ingestion and processing pipelines.
• Supporting the integration of AI-driven functionality into customer-facing products.
• Owning software quality, observability, deployment, and release processes.
• Collaborating with product and engineering teams to translate requirements into production-ready solutions.
• Contributing to the growth and development of the software function as the business scales.

Your Skills & Experience

• Strong commercial experience building and shipping production software.
• Proven experience developing and deploying mobile applications.
• Hands‑on experience working with Bluetooth Low Energy (BLE) connected devices.
• Strong knowledge of AWS cloud services, infrastructure, authentication, and data systems.
• Full stack development capability across frontend, backend, and infrastructure.
• Experience leveraging AI tools and understanding how AI can enhance product experiences.
• Comfortable operating in fast‑moving environments with high levels of ownership.
• Strong communication skills and the ability to collaborate across technical and non‑technical teams.

Desirable experience:

• Health technology, regulated environments, or sensitive data applications.
• IoT platforms and connected device ecosystems.
• Time‑series data, signal processing, or analytics‑focused products.
• Over‑the‑air firmware updates.
• Mentoring engineers or contributing to technical leadership.
• Early‑stage startup or scale‑up environments.

What They Offer

• Genuine ownership of a core product and technology stack.
• Significant exposure to senior leadership and strategic decision‑making.
• Clear progression into technical leadership as the company grows.
• Opportunity to help shape engineering culture, processes, and future hiring plans.