lewisdeane.com

Hey, I'm Lewis

Introduction

I'm a Staff-level AI Product Engineer based in London with experience across big tech and early-stage startups. I care about using my career to make a difference and I'm passionate about building great products that solve meaningful problems.

I'm currently at Tessl, building an agent enablement platform focused on helping developers get better results from coding agents. Before this, I was a Founding Engineer and Tech Lead at ClimateAligned, a pre-seed climate finance AI startup, where I built products using LLMs, agents, RAG, and complex data workflows. Prior to that, I worked at Microsoft and Metaswitch, leading engineering teams and delivering complex systems at scale.

My background combines a BSc in Mathematical Sciences and an MSc in Climate Change Policy with deep product and engineering experience. I bring product thinking, startup execution speed, and applied AI expertise to building products where AI can deliver real value.

Work

My focus is on Product Engineering and applied AI, with a strong interest in leading teams, mentoring others, and turning complex problems into shipped products.

Tessl, 2025–Present

I'm currently a Member of Technical Staff at Tessl, working on building an agent enablement platform. I'm focused on building infrastructure including MCP spec registries and CLI tooling that helps developers get better results from coding agents.

ClimateAligned, 2023–2025

I joined as a founding engineer at ClimateAligned, a pre-seed AI startup focused on sustainable finance. Over time I stepped into the Tech Lead role, guiding senior engineers and setting technical direction across frontend, backend, and AI systems. I:

  • Built a bond data platform using complex LLM workflows to extract structured, high-quality data for a market-level web app.
  • Designed an internal DAG-based workflow builder enabling scalable custom data delivery projects for multinational financial institutions.
  • Developed an agentic dashboard builder automating repeatable analysis tasks into user-facing dashboards. I delivered at pace through multiple pivots, maintaining engineering quality and ensuring the team kept aligned with the fast-moving AI landscape.

Microsoft, 2021–2023

I worked as a Senior Software Engineer at Microsoft in the Teams organisation, where I:

  • Led a 10-person engineering team, delivering projects on time and to a high standard.
  • Delivered large cross-team projects, collaborating across product and engineering groups.
  • Contributed to architecture, technical writing, and project management alongside coding.
  • Championed accessibility, embedding it across processes and product design.
  • Mentored engineers through one-to-one conversations, talks, and written guidance.

Metaswitch, 2018–2021

At Metaswitch (later acquired by Microsoft), I worked as a Senior Android Engineer on a complex VoIP communications app. I delivered projects including:

  • Migrating the app to Kotlin
  • Achieving Accessibility compliance
  • Replacing the legacy HTTP stack
  • Integrating advanced VoIP features with native phone systems I also helped scale the team from 3 to 10 engineers and mentored colleagues at different levels.

Side Projects

I'm currently actively working on two side projects:

#1 Crumbs

A modern recipe app designed to make cooking more accessible and enjoyable.

Goals

  1. Scan and centralise recipes from across all my cookbooks.
  2. Make it easier to follow a recipe with better UX.
  3. Suggest meals and produce shopping lists based on what's available.

Features

  1. Recipe scanning from photos or links using vision and LLM extraction.
  2. Dynamic recipe suggestions based on what you have available, dietary requirements, cuisine preferences, and more.
  3. Ingredient-method linking enabling you to tap an ingredient and see where it's used in the recipe and vice versa.
  4. A feed of photos of meals you've made to get inspiration.

#2 Happy Belly

A food and wellness tracking app helping users understand how their diet affects their wellbeing.

Goals

  1. Make logging symptoms and tracking food as low friction as possible.
  2. Provide proactive and dynamic insights into your health and wellbeing based on your diet and lifestyle.
  3. Make it easy to ask exploratory questions about your health and wellbeing, in the context of your tracking.

Features

  1. Voice and text input for easy input, no complex forms or overly structured data entry.
  2. Daily summaries, insights, and trends based on your day's entries compared to previous days.
  3. Daily personalised suggestions for small tweaks to your diet and lifestyle.
  4. Chat feature where you can ask an LLM about anything related to your health and wellbeing, with the context of your diary entries and dietary requirements.

Contact

If you've got any interesting opportunities or simply wish to discuss anything on this website then drop me a note.

Contact me on LinkedIn or via email at lewis [at] lewisdeane [dot] com.