Guilherme Dantas

Product Engineering Leader and Software Architect

Berlin, Germany | gamsd.com

Hands-on engineering leader with over 20 years of experience building software and scaling technology organizations. Proven track record in modernizing legacy systems, transforming engineering teams, and driving business outcomes through technical strategy.

Core competencies: Engineering Leadership and Team Building; Technical Strategy, Architecture and Development; Distributed Systems Design; Coding!

Currently

Independent Engineering Leadership Advisor

Since April, 2024

Advising established startups and also founders on the prototyping stage on topics such as: interview pipeline planning and execution; staffing, compensation and retention strategies; prototyping and AI workflows for non-technical founders.

Experience

Principal Engineer @ Midlane

July, 2023 - March, 2024

Building HR tools for deskless workers

• Built engineering team from scratch to 5 engineers, with 100% successful hiring rate
• Led architecture and infrastructure decisions that enabled moving from prototype to production in 1 month and first paying customer within 6 months
• Established lean security and infrastructure practices, achieving production reliability with near-zero maintenance overhead
• Researched and developed prototypes and initial integrations with HR platforms (Personio, Kombo.dev, SAP), enabling core product functionality

Typescript, React, Next.js, Vercel, Postgres, Neondb, AWS, SAP, security, risk management, ISO27001, engineering management, technical leadership

VP Product Engineering @ Passbase

February, 2022 - July, 2023

AI-based identity verification platform with manual verification support (acquired)

• Unified previously siloed product and engineering teams (~25 people) and established a product-driven engineering culture that improved velocity and retention
• Simplified development processes, from rigid planning to balanced approach between fewer major product initiatives and engineer-driven continuous improvement
• Led strategic cost reduction ($1MM annually) during market downturn while enhancing product quality and positioning company for successful asset acquisition exit
• Upgraded infrastructure to SOC 2 readiness and CIS AWS Benchmark compliance, while cutting 80% of cloud costs
• Implemented and managed security practices like incident management, vulnerability management and bug bounty / responsible disclosure programs.

Ruby on Rails, Go, Postgres, Redis, Terraform, AWS (in particular AWS Rekognition), Temporal, Watermil, Sidekiq, driftctl, SaaS, cloud, security, privacy, compliance, risk management, soc2, iso27001

Senior Engineering Manager / Domain Architect @ Klarna

February 2019 - January 2022

User Accounts, KYC, AML/CTF screening and monitoring, RTBF, and other compliance systems

• Led 20 engineers across 3 different teams on topics connected to user accounts, privacy and compliance within a regulated banking environment
• Developed leadership pipeline that enabled smooth transition to newly promoted leaders
• Scaled legacy critical-path user accounts service from 1k RPS to 60k RPS, before decommissioning it without major incidents
• Provided technical leadership for cross-functional domain team including directors, business developers, data analysts and legal professionals, and represented this team on cross-domain technical initiatives
• Led engineering excellence initiatives such as threat modelling, incident management training, and system design reviews

Java, Spring Boot, Ruby on Rails, Postgres, MySQL, Python, AWS (RDS, Aurora, Lambda, API Gateway, DynamoDB, Redshift, Athena, DMS), Legacy services, microservices, serverless, architecture, engineering management, leadership, compliance

Senior Software Engineer @ Zalando

October 2016 - January 2019

Merchant Onboarding and Analytics for Zalando’s Partner Program

• Redesigned Merchant Profile service architecture, improving stability and maintainability by eliminating complex actor patterns, supporting stable and fast merchant onboarding (including critical financial data handling) to Zalando’s Partner Program
• Architected and implemented analytics and tracing system for tracking merchant package deliveries for Partner Program purchases
• Built MVP for predictive delivery time estimation for Partner Program purchases
• Enhanced company-wide systems performance monitoring by implementing load balancer percentile tracking
• Provided Scala, architecture, observability and testing mentoring within my teams, resulting in improved code quality and team capabilities

Scala, Akka, Http4s, Java, Spring, AWS, Kubernetes, Prometheus, Postgres, Machine learning, technical leadership

Senior Software Engineer @ Vivareal.com.br

April 2014 - August 2016

Leads, Listings, Locations and Developments services for a real estate search portal

• Established technical foundations for event-stream architecture by introducing Scala, Akka, Reactive Streams and functional programming
• Developed key new services (Developments, Locations) using Scala and reactive programming principles
• Redesigned and rebuilt critical Leads API, increasing lead processing by 30% through eliminating system failures
• Maintained and improved legacy systems based on Groovy/Grails and Java6/Vaadin, replaced them with new systems based on Ruby on Rails and Java8/Spring.
• Rescued an unreliable system that had to be restarted every morning, turning it into a available service with 99.9% uptime, eliminating customer disruptions

Scala, Akka, Finatra, Java, Vraptor, Spring, Ruby, AWS, Node.js, Mongodb, Postgres, Redis, Legacy modernization, async programming, event streaming, technical leadership

Previous Work

Software Engineer @ Peixe Urbano

December, 2012 - November, 2013

scala, lift, mongodb, rest, javascript, ruby, aws, .net, asp.net, c#, continuous-delivery

Software Engineer, Consultant @ Radix Eng

December, 2010 - November, 2012

.net, c#, asp.net, sharepoint, javascript, sql-server

Lead Linux Developer @ Itautec-CIn UFPE

January, 2010 - December, 2010

c, linux-device-drivers, scrum, cmmi, java, spring, continuous-integration

Intern Linux Developer @ Itautec-CIn UFPE

April, 2008 - December, 2009

python, qt, c, linux-device-drivers

Education

Bachelor of Computer Science @ Federal University of Pernambuco, Brazil

2004 - 2009

java, c, vhdl, haskell, linux, signal-processing, python, tdd, continuous-integration, software-engineering, agile, scrum, cmmi, project-management

• Teaching Assistant: Digital Systems / Logical Design (2 years)
• Teaching Assistant: Formal Logic (6 months)
• Graduation Work: Agile Methodologies in a CMMI 3 Context: Case Study