Portfolio · Builder and seller

I build the systems that find, qualify and keep customers. Then I sell with them.

I'm Leandro. At LabsCubed, my full-time job, I work next to sales on $100k technical deals and built an inbound scoring agent that runs three times a day. On the side, I ship my own products end to end.

See the work Resume (1 page)
9

verified sending domains on Resend, across LabsCubed and my own projects

0 of 124

human-confirmed fake leads scored HOT or WARM by my qualifier at LabsCubed

~$600k

in pipeline at LabsCubed accounts engaging with my emails (6 of 10 new deals)

35k

emails sent in the last 30 days from my own projects, outside LabsCubed

How I work

01

Build from scratch, then write the playbook

15 years in agencies creating solutions that generate sales and qualified leads for small and medium businesses that had no marketing or sales pipeline. I was responsible for winning and keeping the agency's clients. Each playbook came from what I saw we could improve.

02

Start from a real problem

Everything I build comes from a problem I lived, or one a friend or a company I worked for had. Real experience first, without reinventing the wheel.

03

Test, measure, iterate

A 50% click rate looked wrong. Timing data showed 71% of clickers were security scanners. 431 real people remained.

04

Write it down

The inbound qualifier has an 8-page playbook. Every scored lead reaches sales as a ready-to-use brief in Slack and HubSpot.

05

Technical enough to build it

APIs, webhooks, sending domains and deliverability across 9 domains. Claude connectors for three products.

06

Care about craft

I design the UI, the UX, the brand and the concept around each problem I want to solve, starting with my own.

Full-time job

At LabsCubed

LabsCubed is where I work full-time. Here is the company, then four problems I solved there, what I built for each, and what changed.

labscubed logo

LabsCubed

labscubed.com ↗My full-time job

B2B lab equipment, about $100k per system

34.9k delivered
How it uses Resend
BroadcastsSegmentsTransactionalWebhooks
Resend API in use
POST /emailsPOST /broadcasts/segmentswebhooks
Workflow
Netlifyform→Claudeverify→Apolloenrich→Firecrawlread website→Claudescore vs ICP→Slackbrief→HubSpotCRM→Resendbroadcasts→Supabasewebhook events
Design system

I built an entire design system for LabsCubed, and the tools for lead qualification.

Email marketingSocial media contentWebsite creationLead qualification toolsMetrics portal for all marketing channelsin development
Inbound qualification

An AI agent that qualifies every inbound lead

Problem

Every website lead was triaged by hand. I audited 2,514 accounts an earlier process had scored HOT or WARM. 52% were not buyers at all.

What I built

An AI agent that verifies each inbound lead, enriches it with Apollo, reads the company's website with Firecrawl and scores it against our ICP, three times a day. It hands sales a ready-to-use brief in Slack and HubSpot. It scores from what the company's own website says, never from a vendor label.

Result

6,539 runs. A median of 2.4 hours from form to sales brief. 0 of 124 human-confirmed fake leads were scored HOT or WARM, and 56% of inbound is filtered out before it costs sales time.

Capture→ Verify→ Enrich→ Read→ Score→ Route
Read the playbook (8 pages) →
Internal buy-in and migration

I've sold Resend to my own company

Problem

LabsCubed sent email from HubSpot, and the website ran on Webflow and Make.com. A new page took hours, and wiring forms and tracking took engineering work.

What I built

I made the internal case for Resend, won it, migrated sending, and kept HubSpot as the sales CRM. Then I connected the two, and retired Webflow and Make.com by moving the whole website to Claude and Netlify. A new page went from hours to 5 minutes.

Result

The newsletters and event campaigns book meetings and nurture leads with materials that keep marketing and sales aligned. 22 broadcasts, 34.9k emails delivered, 55 to 63% opens on event sequences, 1 spam complaint. About $600k of $941k in new pipeline (6 of 10 deals) sits at accounts that read those emails.

Built for a customer, on a deadline

I fixed my own booth tool overnight, and leads doubled

Problem

Every trade show leaked pipeline: lost business cards, half-written notes, no qualification. My first tablet version captured about 10 leads on day 1, then visitors stalled at the step that sends them our materials by email.

What I built

A Lab Assessment on a tablet at the booth, in the visitor's own technical language. It runs before the machine demo, so every conversation starts from real needs. Built from scratch with Claude, Supabase and Resend in two hours. That night I cut the form down, added a business-card and badge scanner that uses the Gemini API to read each format and fills the fields from one photo, added one-tap buttons to send the material, and checked that Resend delivered every email.

Result

Day 2 brought roughly double the leads of day 1, just from simplifying the flow. Every visitor leaves as a scored lead, and Resend sends material matched to their choices.

Measurement

The click rate was lying

Problem

The dashboard showed a 50% click rate. The B2B norm is 2 to 5%.

What I built

I piped every Resend webhook event into Supabase and looked at timing. 71% of clickers clicked within 2 minutes of delivery and hit every link. Those were security scanners. I wrote a human-click filter.

Result

431 real people at 271 companies. Sales now calls accounts that actually clicked.

50% clicks 431 real people

How I read a customer account

Here is LabsCubed's Resend account, read the way I'd read a customer's.

Signal
4,181 of 5,000 contacts used, with the year's biggest trade show ahead
What it means
Expansion: this account hits its limit within months
What I'd do
Reach out before the failed import, not after. Offer the list cleanup first and the upgrade second.
Signal
92.7% delivery, about 240 addresses bouncing on every send
What it means
Health risk: one bad quarter away from blaming the tool
What I'd do
Send a three-line note with the fix. Helpful first, no call needed.
Signal
139k events exported to an external database
What it means
Power user building around a gap
What I'd do
Ask what they built and why. Bring it to product.
Friction log, from the customer's seat
01The API keeps aggregated metrics for about 30 days, so I built my own event store with webhooks.
02The dashboard counts security scanners as clicks. I'd want a human-click view.
03Automatic suppression blocked 2,721 sends to addresses that had already bounced. It protected our reputation without me asking. I'd tell every enterprise buyer about it.

I know what good inbound data looks like, and where it lies to you.

Projects I'm involved in

Selected work

Outside my day job, now with AI, I turn ideas into products, to learn and to partner with companies in the niches I know. These four started from my own problems, or from someone close to me.

Built for my brother

TanoCaixa

tanocaixa.com ↗
Problem

My brother is a delivery restaurant consultant in Brazil. His service could not scale without software.

Why

I built it for him: to grow his consulting and add SaaS revenue from the restaurants he advises.

Solution

A finance app for restaurants. A photo of a receipt becomes the books.

Built from 15 years of agencies

WiseFunnel

wisefunnel.io ↗
Problem

Pay-per-lead and lead generation agencies need one place to build funnels and route leads.

Why

I spent 15 years in agencies, building solutions that generate sales and qualified leads and winning and keeping clients. This is everything I learned.

Solution

Quiz funnels and lead routing in one tool.

Built from my first job in Canada

CarvCAM

carvcam.com ↗
Problem

At my first job in Canada I was the marketing manager for a machine I could not use myself.

Why

I had the problem first-hand.

Solution

Users create their carvings with a simple prompt in Claude and send the files to Sienci Labs machines.

Built for my own website

Visiflow

visiflow.me ↗
Problem

I did not know who was visiting the website I built for LabsCubed.

Why

I wanted to improve its conversion rate and know what to build next.

Solution

Session recordings, heatmaps and funnels for any website, with a single line of code. It now runs on every project I work on.

Products I've built

Five projects of my own, and the emails they send.

Built end to end

Everything here was built entirely by me, outside my day job.

UIUXAPI integrationsMCP serversResend integrationStripe paymentsLanding pageSEO
retrofoot logo

Online football manager game for Brazil

I convinced my partners to use Resend not only for onboarding, but as the tool that sells subscriptions: paywall conversion and win-back emails.

3,280 users, 90 paying. 35k emails in the last 30 days, 98% delivered
How it uses Resend
Event-triggered automations12 segments synced from the databaseBroadcastsSao Paulo regionPaywall conversionWin-back
Resend API in use
POST /events/send8 automations8 events/contacts/segmentsPOST /broadcastsscheduled_at/templatessa-east-1
Workflow
Player event→Databaseworks out stage→Resend12 segments→Resendtriggered email→Resendbroadcasts
wisefunnel logo

WiseFunnel

wisefunnel.io ↗In validation
Official Claude Connectorin review

Quiz funnels and lead routing SaaS I'm launching

My customers verify their own sending domains inside my product
How it uses Resend
Lead deliveryInboundWebhooksCustomer sending domains through the Domains API
Resend API in use
POST /domainsPOST /domains/{id}/verifywebhook: domain.*email.receivedPOST /emails/topics
Workflow
Quiz funnel→Lead routing→ResendDomains API→Resendlead delivery→Resendwebhooks + inbound
tanocaixa logo

TanoCaixa

tanocaixa.com ↗In validation

Finance app for restaurants in Brazil: a photo of a receipt becomes the books

38 templates, one onboarding track per role
How it uses Resend
AuthBilling and dunningOnboarding by roleInactivity win-backMonthly reportsFeature and tutorial emails
Resend API in use
POST /emailstemplate alias tnc-*/contacts + custom properties/segmentssa-east-1
Workflow
Receipt photo→Books→Resendauth→Resendonboarding by role→Stripebilling→Resenddunning + win-back
visiflow logo

Visiflow

visiflow.me ↗In validationOfficial Claude Connector

Session recordings, heatmaps and funnels for any website, with a single line of code.

9-email onboarding
How it uses Resend
OnboardingWelcomeInstall
Resend API in use
POST /events/sendevent visiflow.signed_up/contactsautomationtemplate alias visiflow-*scoped API keys
Workflow
Signup→Resendwelcome→Resendinstall→Resend9-email onboarding→Claudeconnector
carvcam logo

CarvCAM

carvcam.com ↗In validationCustom Claude Connector

Users create their carvings with a simple prompt in Claude and send the files to Sienci Labs machines.

Onboarding and tutorial emails that introduce each feature
How it uses Resend
Onboarding emailsTutorial emailsWelcome
Resend API in use
SMTP via Supabase Auth
Workflow
Signup→Resendonboarding→Resendfeature tutorials→Claudeprompt to carving→Sienci Labsfiles to the machine

RetroFoot's database works out each player's stage and keeps 12 Resend segments in sync. Five player events trigger the right email: signup, no first match after 24 hours, stuck at either paywall, and 7 days away.

The stack behind all of it

CodeReactTypeScriptNode.jsPostgreSQL
BuildClaude (Code, MCP, agents)NetlifySupabase
Find and enrichApolloFirecrawlApifyFindyMailDataForSEOIPinfo
SendResend
SellHubSpotSlack

Also on Resend: Waterloo City FC (8 form confirmations), KW League. 94 templates in total.

The projects, live

LabsCubed, my full-time job, and the projects I'm building to learn about AI, product development and sales strategies. Click one to see it in full.

About

I sit between the product and the customer. I can hold the technical conversation, build the thing that proves the point, and write down what I learned so the next person starts further ahead.

Now

LabsCubed, full-time. I work next to sales on $100k technical deals and run inbound, email and the website.

Before

15 years in agencies creating solutions that generate sales and qualified leads, responsible for winning and keeping the agency's clients.

Building

On the side, projects I'm involved in: RetroFoot, WiseFunnel, TanoCaixa, Visiflow and CarvCAM, each built entirely by me.

Based

Kitchener, ON · UTC-5

Let's talk.

Tell me what you're selling or building. I reply within a day.

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