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Software Engineer Fullstack

On-site in London·Added 3 days ago (last checked 9 Oct)

Throxy

3 open roles

Overview

Requirements

  • Work on-site in London

    No relocation package mentioned.

  • Have 3+ years of experience

    Mid-level role.

Skills

Nice to have

Requirements

What we're looking for

01Professional software engineering experience: 3+ years for mid-level, 6+ years for senior roles

02Fullstack web development skills: comfortable building in both the frontend and backend

03Strong fundamentals in computer science: data structures, algorithms, performance trade-offs

04TypeScript and React experience (Next.js is a big plus)

05A CS degree or equivalent from a strong university

06Based in the UK or willing to relocate to London (we sponsor visas, including your spouse)

The role

Build the engine behind the outcome:

Most applied AI companies sell tools. throxy sells the work itself: pipeline that closes revenue. Our customers don't care how it happens. They care that it does. That distinction changes everything about the engineering. Every improvement we ship makes the service faster and harder to compete with. Better models don't threaten us. They compound us.

We have product-market fit, month-over-month growth, and a clear roadmap. Small, senior engineering team where your code directly drives revenue. This is a rare window: early enough to build foundational systems, our customers range from Fortune 500s to the fastest-growing startups.

North Star

Own problems end-to-end. You'll build the systems you've seen at other companies, from scratch, with real users from day one. Scope it, build it, ship it, iterate.

Why throxy

01

The model compounds you

Every AI improvement makes our service faster and harder to compete with. You're building on a tailwind, not racing against one.

02

Proven, not speculative

Product-market fit, month-over-month growth, and customers paying for outcomes. The business works. Now we need to scale the engineering.

03

Build what you've only seen

Dialer infrastructure, agent systems, intelligence pipelines. The systems you've watched other companies build, you'll own here.

04

The stack:

We're building with TypeScript, React, Next.js, and Bun. Our infrastructure runs on AWS: Postgres, ClickHouse, OpenSearch, and Datadog, with an Elixir core under the dialer. We care about clean code, fast iteration, and engineering excellence.

These are not roadmap items. They are in flight:

01Maestro, Our In-House Dialer

Real-time calling infrastructure on an Elixir core, placing millions of calls a month, with inbound, callbacks, and voicemail detection on local models.

02The Data Engine

Provider waterfalls, LLM qualification and evaluation pipelines, a self-healing lead dataset, and scoring that decides who gets called next.

03The Intelligence Layer

Post-call insights and call-outcome classification, fed back into the next campaign.

04Beyond Off-The-Shelf

Every tool we've outgrown gets rebuilt as our own.

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.

Screening call

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 phase

A hands-on assessment of your coding and problem-solving skills.

Follow-up conversation

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

We aim to move through the full process in 72 hours.

About Throxy

Throxy is a small applied research lab working on the future of sales, backed by Y-Combinator. It runs outbound sales as a done-for-you service, using custom-built technology to uncover niche-specific data, deliver messaging at scale, and book qualified sales meetings for companies selling into traditional industries such as manufacturing, logistics, and construction.

The company describes its approach as flipping "SaaS" into Service-as-a-Software, blending deep research, custom logic, and AI-human workflows to generate real sales opportunities. It reports having served 100+ clients, made 2m+ cold calls, sent 10m+ emails, and generated $100m+ in pipeline.

Industry
Sales Technology
Headquarters
London, United Kingdom
Website
throxy.com

In their own words

About the company & team

A handful of AI-augmented engineers shipping systems that generate pipeline for dozens of customers, Fortune 500s among them. Your work has outsized impact because the team is small and the surface area is large.

All open roles at Throxy