Top Developer Tools Startups in London

170 employeesYC W19Early stage1 open roles

Travel & hospitality Developer tools Mobility & automotive

Duffel

Hiring

What they do:

The complete toolkit to sell travel.

Quick facts:

55 employeesYC S18Growth stage10 open roles

zeroheight

What they do:

The design system layer for coding agents

Quick facts:

55 employeesYC S19Growth stageRemote

Data & analytics Developer tools

Lightdash

Hiring

What they do:

The open source Looker alternative

Quick facts:

23 employeesYC S20Growth stage2 open rolesRemote

Productivity & automation Developer tools

Raycast

What they do:

Speed up non-coding tasks for engineering teams

Quick facts:

27 employeesYC W20Growth stageRemote

Wellness & mental health Digital health & care Developer tools

Junction

Hiring

What they do:

API for at-home health data

Quick facts:

19 employeesYC W20Growth stage9 open rolesRemote

Gaming Developer tools Cloud & infrastructure

Heroic Labs

What they do:

Social Infrastructure for Games; Makers of Nakama game server, Satori…

Quick facts:

21 employeesYC S15Growth stage

Meticulous

Hiring

What they do:

Automated e2e screenshot testing without writing or maintaining tests

Quick facts:

15 employeesYC S21Growth stage6 open roles

Developer tools Applied AI & ML

Trigger.dev

What they do:

Build and deploy fully‑managed AI agents and workflows

Quick facts:

17 employeesYC W23Growth stage

Cosine

Hiring

What they do:

Fully Agentic SWE

Quick facts:

12 employeesYC W23Early stage4 open roles

cubic

Hiring

What they do:

AI-powered code review platform

Quick facts:

6 employeesYC X25Early stage

Applied AI & ML Developer tools Insurance

Parsewise

Hiring

What they do:

Multi-document processing for your risk teams, AI agents, pipelines

Quick facts:

6 employeesYC X25Early stage

Vibe Kanban

What they do:

Plan and review AI generated code

Quick facts:

10 employeesYC S21Early stage

Convoy

What they do:

Webhooks Gateway for outgoing and incoming webhooks.

Quick facts:

8 employeesYC W22Early stageRemote

AI infrastructure & models Applied AI & ML Developer tools

Laminar

What they do:

Understand why your AI agent breaks. Iterate fast to fix it.

Quick facts:

6 employeesYC S24Early stage

Developer tools Applied AI & ML Data & analytics Cloud & infrastructure

HelixDB

What they do:

The fastest & most scalable graph-vector database on the market

Quick facts:

6 employeesYC X25Early stage

Developer tools Data & analytics Cloud & infrastructure

QuestDB

Hiring

What they do:

Data platform for mission-critical real-time workloads

Quick facts:

YC S20Early stage

Developer tools Productivity & automation

Stacker

What they do:

Turns spreadsheets into internal apps and customer portals

Quick facts:

4 employeesYC S20Growth stageRemote

Applied AI & ML Developer tools Cloud & infrastructure Productivity & automation

Unify

What they do:

Models that keep learning

Quick facts:

3 employeesYC W23Early stageRemote

RunLocal AI

What they do:

AI agent that optimizes inference for embedded compute like Jetson

Quick facts:

3 employeesYC S24Early stage

Applied AI & ML Developer tools Cloud & infrastructure Legal, compliance & gov

Inth

What they do:

Monitor and fix product privacy issues before they block growth

Quick facts:

3 employeesYC X26Early stage

Applied AI & ML Developer tools Cloud & infrastructure

Composal

What they do:

Swarms of agents acting like users to find bugs before release

Quick facts:

3 employeesYC F26Early stage

Developer tools Applied AI & ML Data & analytics

Evidently AI

What they do:

Open-source monitoring for machine learning models

Quick facts:

2 employeesYC S21Early stageRemote

Developer tools Applied AI & ML Cloud & infrastructure

Metoro

What they do:

AI SRE For Teams on Kubernetes

Quick facts:

2 employeesYC S23Early stage

Data & analytics Developer tools

Metofico

What they do:

No Code Data Analysis for Life Science Research

Quick facts:

2 employeesYC W24Early stageRemote

Applied AI & ML Developer tools Gaming

ideate.xyz

What they do:

ideate.xyz is an AI-powered 3D art suite on the web

Quick facts:

2 employeesYC S24Early stage

Cloud & infrastructure Applied AI & ML Developer tools

Artil

What they do:

Persistent email inbox, phone number and secret storage for agents

Quick facts:

2 employeesYC W25Early stage

Education Applied AI & ML Developer tools

Chiron

What they do:

Grammarly for Math ✏️

Quick facts:

2 employeesYC X25Early stage

AI infrastructure & models Applied AI & ML Developer tools

mlop

What they do:

Experiment tracking for training ML models

Quick facts:

2 employeesYC X25Early stage

Applied AI & ML Developer tools Cloud & infrastructure

Acyclic Labs

What they do:

Agent swarms that make long-running tasks exponentially faster

Quick facts:

2 employeesYC F26Early stage

Data & analytics Developer tools

Vizzly

Acquired

What they do:

Customer-Facing Analytics for Modern SaaS.

Quick facts:

4 employeesYC S22Early stageRemote

Developer tools Applied AI & ML Cloud & infrastructure

Shuttle

Shut down

What they do:

Build Backends. Fast.

Quick facts:

12 employeesYC S20Early stage

Applied AI & ML AI infrastructure & models Data & analytics Developer tools

Atla

Shut down

What they do:

The improvement engine for AI agents

Quick facts:

10 employeesYC S23Early stage

CodeStory

Shut down

What they do:

Aide is an AI-native , privacy-first IDE built on top of VSCode

Quick facts:

4 employeesYC S23Early stage

Storyline

Shut down

What they do:

Create Alexa Skills without coding

Quick facts:

3 employeesYC W18Early stage

Developer tools Applied AI & ML

Invaria

Shut down

What they do:

The next generation logging and observability platform

Quick facts:

3 employeesYC S24Early stage