Leonardo Pereira

Senior Engineer based in London, Canada 🇨🇦 — currently at Shopify.

I’ve spent my career moving ideas into incredible products. I love Ruby and Rails, use the best of modern TypeScript to create amazing experiences, and teach engineers how to write beautiful code and get better at the craft.

STATUS● ONLINE ROLESENIOR ENGINEER FOCUSSHIP PRODUCT / SHARPEN TOOLS LOCAL TIME--:--

MOD.02 Mission Log REC.2007—

2024 — PRESENTACTIVE

Shopify / Senior Engineer · Growth

Growth engineering at Shopify — monetization and conversion work on surfaces customers actually use.

2024

Hona / Staff Software Engineer

Early-stage full-stack product work: architecture, delivery habits, and enough hands-on code to keep decisions honest.

2023 — 2024

OrderProtection.com / Staff Software Engineer

Architecture across 8+ services, with a lot of TypeScript, React, Preact, and quality work on the customer experience.

2020 — 2023

Route / Senior Software Engineer

Defined code standards and architecture for a high-traffic e-commerce protection platform; mentored 5+ engineers and shipped merchant integrations end-to-end.

2018 — 2020

Decisiv / Senior Software Engineer

Scalable Rails applications for fleet service management, delivered cross-functionally.

2016 — 2017

Silverfin / Software Engineer · Ghent, Belgium

Financial reporting tooling, built with a distributed multicultural team.

2007 — 2016

Earlier / Trat.to · Skore.io · Focus Networks · independent

From PHP-era contract work to technical leadership — consulting, digital wallets, learning platforms, and a lot of shipped side quests.

MOD.03 Product Engineering + Tooling SHIP.MODE

I’m a product engineer first: I like taking fuzzy ideas, shaping them into something real, and sweating the details until the experience feels right. Rails and TypeScript are the main tools in my hands; AI, agents, and Pi are leverage I build around the craft — useful for context, review, testing, and moving faster without giving up judgment.

001 // product

Shape ideas into product

I like the messy middle: turning a rough problem into flows, boundaries, data models, and small decisions that make the thing shippable.

002 // craft

Build with Rails, sharpen with TypeScript

Ruby and Rails are home base. Modern TypeScript, React, and careful UI work help me turn solid systems into experiences that feel fast, clear, and human.

003 // tooling

Use agents as leverage, not identity

I build Pi workflows, skills, prompts, and extensions that help inspect code, compare paths, test changes, and keep more context in the room.

004 // quality

Teach the taste behind the code

I care about helping engineers build judgment: readable code, honest tests, good trade-offs, and the confidence to know when simple is better.

MOD.04 Labs EXP.RUN

000rpgmenace.com.brproject nostalgic bulletin board 001A* Pathfindingexperiment interactive search with heuristics and mazes 002Level Up Growthexperiment flat, quadratic, exponential growth curves 003Softmax Visualizationexperiment raw scores into probability distributions 004Solar System Gravityexperiment real-time orbital physics simulation 0053D Snake Gameexperiment classic snake switching between 2D and 3D 006Bezier Targeting 2Dexperiment FF12-inspired targeting curve and firing loop 007Bezier Targeting 3Dexperiment 3D control spheres, orbit camera, projectile arc 008Seasonal Meridianexperiment Earth–Sun seasons, daylight, and axial tilt 009Einstein Field Labstudy equations, coordinate maps, explanations, and physical animations 010pi-coderopen source interactive code workbench and diff review UI 011pi-promptopen source prompt planning and specification workflow 012pi-agentic-searchopen source ranked repo search for coding agents 013pi-extended-teamsopen source multi-agent orchestration for Pi 014pi-feedbackopen source structured feedback across Pi sessions 015pi-introopen source cinematic startup overlay for Pi 016pi-render-images-tmuxopen source render images inside tmux 017pi-retitleopen source generated session and tmux titles 018pi-system-monitoropen source live system metrics for Pi 019pi-tasksopen source task tracking for agent workflows 020pi-thinking-messagingopen source elapsed time and token activity 021pi-yoloopen source checked commit, push, and deploy workflow

MOD.05 Comms CH.OPEN

Use / to access terminal. Easter egg game available.