Haystack
← Back to Jobs
Full time
Technology
CL

Founding Full-Stack iOS Engineer

CleraLondon🇬🇧United KingdomPosted 19 Sept 2026

Why This Role Stands Out

As a founding Full-Stack iOS Engineer at a Y Combinator-backed startup, you'll have significant ownership over a groundbreaking consumer product and shape its future. This role is perfect for a mid-senior engineer with strong Swift skills who thrives on building intuitive interfaces for complex data and desires a hands-on impact in an early-stage, innovative environment. Embrace this opportunity to define a truly unique user experience and grow with a pioneering company.

Quick Overview

Seniority
Mid Senior
Employment type
Full Time
Location
London, United Kingdom
Posted
22 hours ago
SwiftiOS

Job Description

About the Role

This is a founding iOS engineering role at an early-stage wearable technology startup backed by Y Combinator, building a consumer device that monitors and interprets emotional states in real time. You will own the companion iOS app end-to-end, translating sophisticated AI model outputs into intuitive, polished experiences for users. As one of the first technical hires, you will have real ownership over the primary consumer touchpoint and a direct hand in shaping how the product grows.

What You'll Do

  • Own the companion iOS app from architecture through deployment and ongoing iteration.

  • Surface emotional-state outputs from the core inference model through clean, intuitive app interfaces.

  • Build and ship a polished, consumer-grade mobile experience that meets high product standards.

What We're Looking For

  • At least 2 to 3 years of professional iOS engineering experience; this role is not suitable for fresh graduates.

  • Strong Swift proficiency and a proven track record shipping polished, consumer-grade iOS applications.

  • Experience building data-driven apps that present complex model or sensor outputs through clean, accessible interfaces.

  • Strong computer science fundamentals and the ability to make and own technical decisions autonomously as a founding engineer.

  • Comfortable working independently across time zones and collaborating on a lean, distributed team.

  • Full-stack iOS capability, comfortable owning the app layer end-to-end.

Compensation & Benefits

Salary of $150,000 USD (or approximately GBP 75,000 for London-based candidates), plus meaningful early equity of up to 1 to 2%. No new visa sponsorship is available; visa transfers and OPT transitions are acceptable.

Location

On-site in London, England, UK. The team also has presence in San Francisco; candidates in other locations may be considered on a case-by-case basis.