CTO | VP Engineering | Engineering Leader building scalable systems and high-performing teams

🌍 Based in Berlin, Germany | 🚀 Open to CTO, VP Engineering, and Director roles | 💼 10+ years scaling engineering organizations

I'm an engineering leader with 12+ years of experience scaling teams from 8 to 150+ engineers as CTO, VP Engineering, and Engineering Director at high-growth startups across e-commerce, SaaS, fintech, and AI/ML domains.

I specialize in:

• 🚀 Scaling engineering teams from 8→50+ engineers while maintaining 90% retention
• 🏗️ Building resilient, scalable architectures processing 1M+ transactions per minute
• 🎯 Strategic + hands-on leadership
• 🌍 Multi-market operations across Europe, North America, and Latin America
• 🤖 AI/ML integration with LLMs (Claude, OpenAI), building proprietary algorithms
• 💡 High-ownership cultures through structured programs like "Manager School"

Currently: AI Contractor, building AI-powered geospatial optimization systems

Previously: CTO at Wishpond Technologies, Flowmate, Delta Technologies, and WiseBuffet/Creatrix

• Frameworks: React, Next.js, NestJS, Vue, Svelte, Express
• Mobile: iOS & Android SDK development, React Native
• UI/UX: Responsive design, mobile-first architecture, component libraries
• Testing: Jest, Cypress, Playwright, React Testing Library

• Backend: Node.js, NestJS, Golang microservices, gRPC, GraphQL, REST APIs
• Databases: PostgreSQL (10+ years, optimization expert), MongoDB, DynamoDB, Redis, BigQuery
• Architecture: Microservices, event-driven systems, distributed systems, API design

• Cloud: AWS (EKS, Lambda, S3, SQS, EventBridge, IAM), GCP (Kubernetes, Cloud Run, BigQuery)
• DevOps: Kubernetes, Docker, Terraform, Helm, ArgoCD, CI/CD pipelines
• Observability: Datadog, Grafana, Prometheus, CloudWatch
• IaC: Terraform, Ansible, CloudFormation

• LLM Integration: Claude, OpenAI, multi-agent systems, prompt engineering
• ML Frameworks: PyTorch, scikit-learn, TensorFlow
• AI Applications: Intelligent automation, conversation AI, predictive analytics
• Data Pipelines: ETL workflows, data engineering, analytics platforms

• Platforms: Shopify integration & APIs, marketplace development, payment systems
• Products: Campaign management, marketing automation, abandoned cart recovery, loyalty programs
• Multi-tenancy: SaaS architecture, B2B/B2C platforms, subscription billing

• Scaled engineering from 8→50+ engineers at Wishpond Technologies (90% retention)
• Led 150+ engineers with 8 direct reports at WiseBuffet/Creatrix across 12 time zones
• Created "Manager School" training program: promoted 10+ engineers to management roles
• Built high-ownership cultures with small autonomous teams (5 people max per squad)

• Architected systems processing 1M+ email transactions per minute at scale
• Built Golang microservices with gRPC, handling thousands of requests/second
• Optimized PostgreSQL databases reducing costs 60% (~$40K/month savings)
• Achieved 99.99% uptime across multiple production systems
• Improved system performance by 40% (stability, latency, costs) through architectural optimization

• Built multi-agent LLM frameworks for automated API integration and monitoring
• Developed AI-powered marketing automation products (SalesCloser.ai, Wishpond AI)
• Integrated LLM-based conversation intelligence for real-time CRM automation
• Created ML data pipelines, training models on millions of transactions

• Operated across 8+ countries in Europe, North America, and Latin America
• Built Shopify integrations for abandoned cart recovery, driving 12-18% conversion rates
• Developed marketplace platforms connecting merchants with ecommerce ecosystems
• Partnered with regional GMs, solving market-specific challenges (payments, regulations, UX)

• Reduced infrastructure costs from $100K/month while scaling 3x at Wishpond
• Saved $480K annually through MongoDB optimization at Delta Technologies
• Generated measurable ROI: merchants recovered $8 for every $1 spent on the platform
• Supported products serving 20,000+ businesses and millions of end users

I'm always interested in connecting with fellow engineering leaders, founders, and companies working on meaningful problems. Whether you're looking for technical leadership, want to discuss engineering best practices, or have an exciting opportunity—let's talk!

💼 LinkedIn: linkedin.com/in/denniszelada
📍 Location: Berlin, Germany
🌐 Open to: Remote (Europe/US time zones), Berlin-based, or hybrid arrangements

When I'm not scaling engineering teams or building systems, you'll find me:

• 🚴 Cycling through Berlin (passionate about sustainable urban mobility and e-bikes)
• 👨‍👧‍👧 Spending time with my two daughters (teaching them about technology and sustainability)
• ♻️ Advocating for circular economy and climate tech solutions
• ☕ Brewing specialty coffee and exploring Berlin's coffee scene
• 📚 Mentoring engineers and contributing to open-source communities

"Great engineering leadership isn't about being the smartest person in the room—it's about hiring people smarter than you, creating conditions where they thrive, and making strategic technical decisions that drive business outcomes. Small autonomous teams, high ownership culture, and staying close to the code while providing strategic vision: that's my approach."

CTO Berlin · Chief Technology Officer Germany · VP Engineering Berlin · Engineering Director · Head of Engineering · Technical Leadership · Startup CTO · Scale-up Engineering Leader · TypeScript Expert · Golang Developer · React Specialist · Next.js · Node.js · PostgreSQL · AWS · GCP · Kubernetes · Engineering Team Scaling · Tech Leadership Berlin · Remote CTO · SaaS CTO · E-commerce Engineering · Marketplace Technology · AI Integration · LLM Engineering · Multi-Agent Systems · Engineering Culture · High-Ownership Teams · Manager Training · DORA Metrics · Microservices Architecture · Distributed Systems · API Design · Cloud Native · DevOps Leadership · Engineering Operations · Product Engineering · Full-Stack Leadership · Technical Strategy · Engineering Excellence · Team Building · Hiring A-Players · Performance Optimization · Cost Reduction · 99.99% Uptime · Shopify Integration · Marketing Automation · Climate Tech · Sustainability · Circular Economy · Mission-Driven Engineering

⭐ If you're hiring for CTO, VP Engineering, or Director roles, let's talk!