Throxy
YC X25  ·  London

Software Engineer Fullstack

Location London, UK
Type Full-time · In person
Team Engineering
Stage Early - high impact
Apply now ↗

Build the products that power our growth:

We're a fast-growing startup building the next generation of tools for our industry. Small, opinionated engineering team that moves fast - a dozen engineers shipping features that reach users the same week. Backed by top-tier investors and scaling rapidly. Your code matters from day one.

We're AI-native - not as a marketing line, but in how we actually work. Every employee ships with AI daily. We build LLM-powered products and use AI tooling internally. Most companies are still figuring out where AI fits. We already know.

North Star

Own problems end-to-end: scope, build, ship, iterate. Strong opinions about code quality, thoughtful architecture, and the drive to figure things out independently.

What you'll do:

01
Full-Stack Ownership

Build full-stack features from UI to backend, taking ownership of entire product surfaces.

02
Clean, Readable Code

Write code that others can reason about: clear intent, minimal surprise, well-organised. You've developed taste for what good code looks like, and that includes making it readable for the AI tools working alongside you.

03
AI-Native Development

Work with AI tools as a core part of your development workflow: we're AI-native and expect you to be comfortable planning with and through AI, not just vibe-coding.

04
Systems Architecture

Architect systems with a holistic view: understanding how the frontend, backend, and infrastructure connect and affect each other.

05
Ship Fast

Ship quickly in a startup environment where your work goes live fast and feedback loops are tight.

06
Collaborate

Collaborate with a small, senior team where everyone's input shapes the product.

The stack:

We're building with TypeScript, React, Next.js, and modern AI tooling. Our infrastructure includes SingleStore, OpenSearch, Trigger.dev, and Axiom. We care about clean code, fast iteration, and engineering excellence.

What we're looking for:

  1. 01Professional software engineering experience: 1+ years for mid-level, 5+ years for senior roles
  2. 02Fullstack web development skills: comfortable building in both the frontend and backend
  3. 03Strong fundamentals in computer science: data structures, algorithms, performance trade-offs
  4. 04TypeScript and React experience (Next.js is a big plus)
  5. 05A CS degree or equivalent from a strong university
  6. 06Based in the UK or willing to relocate to London

Strong signals:

01
Top-Tier Experience

Experience at a high-calibre tech company: FAANG, Bloomberg, Stripe, Shopify, Revolut, Datadog, or similar.

02
Startup DNA

Time at a startup or small team (< 20 people) where you wore many hats.

03
AI/LLM Builder

Experience building with AI/LLMs: AI agents, RAG systems, or LLM-powered features.

04
Ships Solo

You've built something end-to-end on your own: a side project, an open source tool, a past business.

Our hiring process:

Screening call (15 min)
We get to know each other. We'll talk about your experience, what you're looking for, and give you a clear picture of Throxy.

Technical exercise (~2h)
A realistic problem that tests your coding and reasoning skills. We evaluate code quality, architecture decisions, and how you think through problems.

Final conversation
Meet more of the team, talk about culture, role expectations, and comp.

We aim to move through the full process in 1-2 weeks.

Why Throxy:

Impact from day one

Small team, big problems, your code ships to users immediately.

🛠️

Engineering-first culture

We obsess over code quality, tooling, and developer experience.

🤖

AI-native workflow

We don't just build AI products. We use AI to build better, faster.

🚀

Growth

We're scaling quickly and there's room to grow into leadership, architecture, or specialist roles.