Founding Staff Engineer (Agentic Systems & AI Infrastructure)

Mytechtree; United Kingdom; On-site; GBP 75,000 - 99,000; Full time

Job summary

A leading technology company in the UK is seeking a Founding Staff Engineer to build AI infrastructure focusing on agent orchestration and reasoning engines. The role requires deep Python expertise and 5+ years experience in backend or AI systems. Join a dynamic founding team solving real and complex problems in AI. Offering competitive salary and 1% equity, this full-time position is perfect for hands-on builders motivated to innovate.

Benefits

1% equity

Qualifications

• 5+ years of experience in backend, infra, or AI systems roles.
• Deep Python expertise.
• Real-world experience building agentic systems.
• Expertise in ontology development, schema reconciliation, and knowledge graphs.
• Strong foundations in modern data infra and cloud (GCP or AWS).
• Background in symbolic AI, reasoning systems, or semantic data modeling.
• Experience at an early-stage startup.

Responsibilities

• Build core agent infrastructure and scalable agent orchestration.
• Engineer automated ontology systems connecting data sources.
• Own agent runtime for planning, tool execution, and observability.
• Scale data infrastructure and maintain metadata stores.
• Advance reasoning engines with LLM + symbolic reasoning pipelines.

Skills

Python

open-source LLM frameworks

LangChain

LlamaIndex

ontology development

schema reconciliation

knowledge graphs

modern data infrastructure

dbt

BigQuery

Airflow

cloud (GCP or AWS)

symbolic AI

reasoning systems

semantic data modeling

AI tools (Cursor)

Windsurf

Cody

Job description

Founding Staff Engineer (Agentic Systems & AI Infrastructure)

Base pay range: $100,000.00/yr - $130,000.00/yr

About The Company

Melow is building the AI Operating System for data. A dynamic ontology engine making sense across all forms of structured and unstructured data - and a new form of AI worker that executes autonomous workflows with transparent human reasoning across real tools. We’re building the AI middleware for the world that lets AI understand data the way only data teams do to reason, plan, and act inside real systems. We’re still in stealth, but already working with some of the most recognized companies in the world across fintech, travel, insurance, gaming, and logistics. We’re builders, solving real and messy problems. Our goal is to define a new software category - and we’re just getting started. We have clients, have raised money, and now want to release what we have built to the world.

About The Role

Join a founding team to build AI infrastructure, focusing on agent orchestration, semantic layers, and reasoning engines. Requires 5+ years in backend/AI systems and deep Python expertise.

What You’ll Own

• Build our core agent infrastructure: Scalable agent orchestration, task planning, memory, and execution logic using Python and open-source LLM frameworks (LangChain, LlamaIndex, etc)
• Engineer automated ontology systems: Design the semantic layer that connects every source - structured and unstructured - into a shared data brain.
• Own the agent runtime: Robust planning, tool execution, and observability for distributed, autonomous systems.
• Scale our data infrastructure: Build and maintain metadata stores, data connectors, ETL, and vectorized storage (Chroma, Pinecone, Weaviate).
• Advance our reasoning engines: Build hybrid LLM + symbolic reasoning pipelines, task decomposition frameworks, and long‑term agent memory systems.
• Define our engineering culture: Set the bar for system design, quality, and speed. Mentor others, help us hire exceptional talent, and drive long‑term architecture.
• Go full‑stack if needed: We move fast – sometimes you’ll ship backend APIs, other times hack together a frontend to get feedback.

Requirements

• 5+ years of experience in backend, infra, or AI systems roles
• Deep Python expertise
• Real‑world experience building agentic systems
• Expertise in ontology development, schema reconciliation, and knowledge graphs
• Strong foundations in modern data infra and cloud (GCP or AWS)
• Background in symbolic AI, reasoning systems, or semantic data modeling
• Experience at an early‑stage startup
• Experience at data native companies like Palantir, DeepMind, Databricks, Snowflake, or early‑stage AI infra startups
• Extremely motivated
• Grit
• Hands‑on builders
• Value‑driven builder

Required Skills

• Python
• open‑source LLM frameworks
• LangChain
• LlamaIndex
• ontology development
• schema reconciliation
• knowledge graphs
• modern data infrastructure
• dbt
• BigQuery
• Airflow
• cloud (GCP or AWS)
• symbolic AI
• reasoning systems
• semantic data modeling
• AI tools (Cursor)
• Windsurf
• Cody

Seniority Level

Mid‑Senior level

Employment Type

Full‑time

Job Function

Engineering and Information Technology

Industries

Software Development

Equity

1% equity