Engineering Leader & Product Builder

Building products from 0→1 at lightning speed, then scaling teams to turn validation into commercial success

Sebastian Lagemann

About Me

I'm a hands-on engineering leader with extensive experience across the full stack. My track record speaks to building products from scratch quickly—turning ideas into validated MVPs in weeks, not months.

Once a product finds its market fit, I excel at scaling engineering teams. I've grown teams from 2 to 15+ engineers, always maintaining high standards while fostering a culture of continuous improvement.

Beyond coding and architecture, I'm passionate about mentoring and developing engineering talent. I believe in creating self-improving engineering cultures where every team member can grow and contribute to excellence.

Rapid Product Development

0→1 in weeks, not months

👥

Team Builder

Growing engineering teams post-PMF/validation

🎯

Hands-On Leader

From architecture to deployment

📈

Growth Catalyst

Coaching, training, and driving continuous improvement

Side Projects

Building products that solve real problems

LLM Flow Designer

Making AI agent development accessible and intuitive

Visual platform for building deterministic AI agent networks without framework complexity. Eliminates the need for LangChain, CrewAI, or AutoGen with precise path control and execution tracking.

AI/MLAgent NetworksVisual ProgrammingTypeScript
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Pregnancy Food Finder

Solving real problems with empathy-driven development

Personalized recipe platform for pregnant women, addressing food aversions and cravings. Built initially for my wife during pregnancy to find nutritious meals that actually sounded appealing during challenging times.

Next.jsAI-Powered RecommendationsHealth Tech
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CoinEcho

Turning noise into actionable market insights

Intelligent crypto news aggregator with automated crawling, categorization, sentiment analysis, and bear/bull market indicators. Real-time market intelligence for crypto traders.

Web ScrapingNLPMarket AnalysisReal-time Data
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HiFreCTRA.ai

Building systems where milliseconds matter

High-frequency trading platform for cryptocurrency exchanges. Algorithmic trading with microsecond precision and advanced risk management.

HFTCryptoAlgorithmic TradingPerformance Engineering
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WizenCraft

🚧 Work in Progress

Modern gameplay meets classic puzzle mechanics

Mastermind-inspired web game with modern gameplay mechanics. Work in progress showcasing game development and real-time interactions.

Game DevelopmentWebSocketsReactReal-time
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Punchmole

Self-hosted alternative to ngrok

Simple tool to give your locally running HTTP(s) servers a public URL. An easy to self-host alternative to ngrok and tunnelmole. Open-source tunneling solution for developers.

Node.jsTunnelingNetworkingOpen Source
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Technical Writing

Sharing insights on engineering, infrastructure, and product development

View all articles on Medium
AI & DevelopmentJune 28, 2025

Cursor AI Deep Dive: Building Professional Products & My Crypto Trading Evolution

A follow-up to my crypto news aggregator journey, exploring how Cursor AI helps build professional products and my evolution in crypto trading.

8 min readRead article
AI & DevelopmentMay 26, 2025

My Crypto News Aggregator in One Afternoon with Cursor

Building a real-time crypto news aggregator using Cursor AI, Next.js, and modern web technologies in just one afternoon.

6 min readRead article
DevOpsOctober 5, 2024

Ubuntu 24.04 automatic virtual machine installation

A comprehensive guide to automating Ubuntu 24.04 virtual machine installation using QEMU and Ansible.

10 min readRead article
DevOpsSeptember 17, 2024

Deploying S3 alternative Minio on Kubernetes

A simple guide to deploying Minio (S3 alternative) on Kubernetes using Makefile and Helm charts.

7 min readRead article
DevOpsSeptember 9, 2024

Deploying Open-Source Slack alternative Mattermost on Kubernetes

Step-by-step guide to deploying Mattermost, an open-source Slack alternative, on Kubernetes.

8 min readRead article
DevOpsSeptember 4, 2024

Deploying Novu on Kubernetes with Community Helm Chart

Guide to deploying Novu notification infrastructure on Kubernetes using Makefile and Helm charts.

6 min readRead article

Skills & Expertise

Building products, growing teams, and driving excellence

Product Development

0→1 DevelopmentMVP CreationRapid PrototypingProduct-Market Fit ValidationAgile MethodologiesUser-Centered Design

Engineering Leadership

Team BuildingTechnical MentoringEngineering CultureHiring & ScalingCode ReviewsArchitecture DesignTechnical Strategy

Frontend & Full Stack

Next.jsReactTypeScriptTailwind CSSFramer MotionWebSocketsReal-time UI

Backend & Infrastructure

Node.jsPythonKubernetesDockerCloud InfrastructureAPI DesignMicroservicesDatabase DesignData EngineeringDatabase Management (NoSQL/SQL)AnsibleBare-Metal

Specializations

AI/ML Integration & EngineeringCustom ML ModelsLLM & Agent NetworksHigh-Performance SystemsReal-time ApplicationsCrypto/BlockchainAlgorithmic TradingWeb Scraping & NLP

Tools & Practices

Git & Version ControlGitLabCI/CD PipelinesTesting & QAPuppeteerDevOpsMonitoring & ObservabilityPerformance OptimizationCursor

Experience Timeline

Key milestones in building products and growing teams

2025AI-Native FinTechRotterdam

Cortena - Co-Founder & CTO

Building AI-native agents that automate financial forecasts and surface insights. Designed LLM analysis tools, real-time chat UI, and agentic systems. Set up infrastructure, CI/CD pipelines, and data aggregation APIs to enable early testers within weeks.

2024Trading & InnovationAmsterdam

Crypto Day Trading & Open Source

Focused on crypto day trading leveraging AI and deep learning techniques. Launched open-source projects including Punchmole (self-hosted tunneling solution) and LLM Flow Designer (visual platform for AI agent networks).

2021-2025AI Gaming PlatformSingapore

slab - Founder & CTO

Founded AI-driven platform for game developers, enabling self-publishing with automated marketing. Built fully remote engineering team and designed early Gen-AI and agentic systems for automated game publishing on App Store and Google Play. Achieved strong early adoption among indie developers.

2017-2022Voice AI & ComplianceNew York

Aigent Inc. - Founder & CTO

Founded and scaled AI-powered voice analytics company from 0 to 30 engineers across Europe and US. Architected end-to-end ML infrastructure with real-time audio processing. Designed PCI-DSS and ISO 27001 compliant cloud environment. Reduced model deployment time by 60% through CI/CD automation.

2016-2017Mobile Gaming ScaleKraków, Poland

Reality Games - Co-Founder & CTO

Co-founded mobile gaming company generating multi-million-dollar annual revenues. Scaled engineering from 3 to 25 people. Developed geo-data platform powering games with over 10 million downloads. Introduced microservice and Kubernetes-based infrastructure for real-time multiplayer experiences.

2014-2016Platform TransformationAmsterdam

iQU - Chief Technology Officer

Transformed digital marketing agency into data-centric marketing intelligence platform. Modernized architecture for large-scale event ingestion and real-time analytics. Consolidated legacy pipelines into fault-tolerant microservice architecture. Achieved 70% faster release cycles through modern CI/CD.

2011-2015Analytics Platform ExitMünchen, Germany

HoneyTracks - Founder & Managing Director

Founded one of Europe's earliest data analytics platforms for gaming industry. Built scalable analytics backend processing billions of in-game events per month. Designed APIs and SDKs used by major gaming studios. Improved game retention KPIs by 30% on average. Successfully exited through acquisition.

2007-2017Payment SolutionsFreiburg, Germany

spirit labs GmbH - Founder & Managing Director

Built worldwide payment solutions company within larger media holding. Managed thousands of daily transactions with small team. Delivered global payment methods (Credit Card, SEPA, Crypto, Premium SMS). Implemented robust fraud prevention and PCI-DSS compliance.

2006-2011MMO Game LeadershipFreiburg, Germany

Mediatainment AG - Head of Development

Led development of 5+ highly profitable MMO browser games from scratch. Games entertained hundreds of thousands of players, with some operating successfully for over a decade. Achieved results with lean, high-performing team.

2004-2006Early Gaming InnovationKarlsruhe, Germany

Gameforge GmbH - Software Engineer

Early employee contributing to company's rapid international growth. Developed international micro-transaction payment system integrating SMS, phone, and early online banking. Maintained large fleet of on-premise servers and built internal tools for localization and payment systems.

Let's Build Something Together

Have a project in mind? Let's discuss how we can bring it to life.

Available for new opportunities