Available for new projects

Stephan Lensch

Software Engineering & Technical Leadership

I help companies build robust, scalable software products. From hands-on fullstack development to leading engineering teams and designing system architectures — I bridge the gap between business needs and technical excellence.

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Years Experience
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Projects Delivered
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Industries Served

Services

End-to-end software engineering consulting, from concept to production.

Fullstack Development

Building complete applications from database to UI, with clean architecture and automated test coverage at every layer.

  • Requirements engineering & implementation
  • Frontend & backend development
  • Test automation (E2E, integration, unit)
  • CI/CD pipeline setup & maintenance

Technical Leadership

Guiding engineering teams to deliver high-quality software through mentorship, sound architecture decisions, and pragmatic processes.

  • Team hiring, onboarding & upskilling
  • Architecture decision-making
  • Code review culture & quality standards
  • Agile process facilitation

Architecture & Consulting

Designing microservice architectures, evaluating technology choices, and translating business requirements into scalable technical solutions.

  • SOA & microservice architecture
  • Cloud infrastructure (AWS, Azure)
  • Technology evaluation & migration
  • Business-tech alignment

Tech Stack

A broad and battle-tested technology toolkit, refined over 15+ years of hands-on delivery.

Backend
Java Spring Boot Typescript NestJS Spring Cloud Hibernate / JPA REST GraphQL Swagger
Frontend
TypeScript React Next Vue.js Nuxt Angular Vuetify Material Design SCSS
Cloud & Infrastructure
AWS Azure Kubernetes Docker Terraform Heroku Netlify
Databases
PostgreSQL MongoDB Redis Oracle Neo4J MySQL Elasticsearch Apache Solr
Messaging & Streaming
Apache Kafka RabbitMQ Apache ActiveMQ
Testing & Quality
Playwright Cypress JUnit Spock Selenium Gatling Mockito
DevOps & CI/CD
GitLab CI GitHub Actions Jenkins Azure DevOps Grafana Prometheus Kibana ELK Stack

Selected Projects

A selection of projects delivered across industries, from startups to enterprise environments.

E-Commerce 2022

Wallbox Online Retail Platform

Fullstack Developer

Built a custom online shop for selling and renting EV charge points, including IoT utilities for warehouse stock management and remote firmware updates via OCPP.

TypeScript NestJS Vue / Nuxt MongoDB Stripe Heroku Cypress
Energy 2021

Electricity Provider Platform

Tech Lead

Led the development of an electricity tariff product for a photovoltaic rental company, integrating Salesforce, an energy ERP, and customer-facing web forms.

Java / Spring Boot NestJS Vue / Nuxt Salesforce Docker MongoDB
Financial Services 2019 – 2021

Investment Management Platform

Tech Lead

Rebuilt an Access-based asset management system into a modern event-sourced platform, enabling complex reporting, fine-grained auditability, and continuous migration.

Java / Spring Boot Axon Framework Vue.js Oracle PostgreSQL Docker
Copyright 2019

Legacy Data Migration Platform

Fullstack Developer

Reverse-engineered a decades-old database and built a migration strategy with visualization tools, iterative migration logic, and Kubernetes-based infrastructure.

Java / Spring Boot Angular Kubernetes Oracle PostgreSQL Cypress
Insurance 2017

Online Car Insurance Portal

Frontend Developer

Delivered an MVP for a direct B2C car insurance product including a rate calculator widget, mobile app via Ionic, and headless CMS integration with Contentful.

Angular TypeScript Ionic Spring Boot Contentful Jenkins
E-Commerce 2016 – 2017

Recipe-to-Product Mapping Engine

Fullstack Developer

Created a fully automated NLP-powered solution linking recipe ingredients to grocery store products, with an embeddable JavaScript widget for partner websites.

Java / Spring React Apache Kafka Apache Solr Docker Swarm NLP
E-Commerce 2015 – 2017

Product Recommendation Engine

Backend Developer

Built a machine-learning-powered recommendation engine using basket analysis and user profiles, processing data at scale with Spark clusters in Google Cloud.

Java / Spring Apache Kafka Spark / MLlib Google Cloud PostgreSQL TensorFlow
Market Research 2014

Big Data Analytics Platform

Big Data Developer

Developed a unified data lake consolidating data silos with ETL pipelines in the Hadoop ecosystem, enabling ad-hoc analysis with data integrity and anonymization.

Spring Hadoop Impala HBase MongoDB Cloudera

Get in Touch

Looking for an experienced software engineer or tech lead for your next project? I'm always open to discussing new challenges and opportunities.

Location
Kleve, Germany

Ready to start a project?

Whether you need a fullstack developer, a tech lead, or an architecture review — let's find out how I can help.

Send an Email

Impressum

Angaben gemäß § 5 TMG

Wels Holding GmbH
Knipweg 63
47533 Kleve
Deutschland

Vertreten durch

Geschäftsführer: Stephan Wels

Kontakt

Telefon: +49 173 5477782
E-Mail: info@wels-holding.com

Registereintrag

Eintragung im Handelsregister:
Registergericht: Amtsgericht Kleve
Registernummer: HRB 14548

Umsatzsteuer-ID

DE 310 902 888