Felix Eckhardt portrait

Senior Full Stack Developer

Building digital products
with 25 years of expertise

Full Stack Developer specializing in Kotlin, Scala, and Rust. Former CTO and business owner with a proven track record in building scalable solutions from startup to enterprise.

25+
Years of Experience
6+
Startups Build & Guided
10+
Teams Supported
4
Industries: E-Commerce, FinTech, Automobile, Health

Latest Work

2025 — 2026

Experience

Apr 2025 — Mar 2026

Cloud In-Cabin Simulation

Interim CTO · Vaiva

Moved the engineering team from a project-focused prototype to a sellable product and first customers. Led development of the cloud-based Unreal Engine simulation (ICASIS) for driver safety, serving clients like VW, Audi, and Renault.

Unreal Engine 5.6Python DjangoPostgresAWS
Jan 2025 — Apr 2025

Just Drink App

Fullstack Developer · Rocket Solutions

Health-focused desktop hydration app built with Rust, Kotlin & Svelte/Tauri. Cross-platform for Windows and macOS.

RustTauriKotlinSvelteSpring Boot
Oct 2024 — Dec 2024

Motion Minute App

Fullstack Developer · Rocket Solutions

Cross-platform wellness application helping users perform desk-friendly exercises. 25,000+ app sessions.

RustTauriKotlinSvelte
Jan 2024 — Sep 2024

Holi Social Challenge

Technical Product Lead · Holi GmbH

Architected and engineered a Social Challenge App. Lead from conceptualization to implementation in a 3-person team.

KotlinSpring BootReact NativeHTMX
Jan 2023 — Jan 2024

levejo E-Commerce

Full-Stack Developer · Igefa GmbH

E-commerce platform built in 4 months to go-live. Vertical cut online shop architecture with advanced product search.

KotlinSpringKafkaVue.jsAstroAWS
Jan 2021 — Jan 2023

Klingel E-Commerce

Senior Developer · Klingel.de

Scala e-commerce shop system for Klingel Group (€1B turnover). 60+ web shops. 28% turnover uplift on personalized start page.

ScalaJavaCats IOAWS PersonalizeKubernetes
Aug 2020 — Dec 2021

Finleap Banking Systems

Developer / Data Engineer (Freelancer) · Berlin

Built an entity recognizer for financial banking transactions with automated customer transaction evaluation and a scalable data processing pipeline.

JavaScalaPythonMLData Pipeline
Feb 2018 — May 2020

Risk.Ident / FRIDA Fraud prevention

CTO / Director · Risk.Ident GmbH

Built Otto B2B Tech Startup. Fraud detection product FRIDA processing 54B transactions/year. €2M+ annual revenue.

ScalaAkkaKubernetesPostgreSQL

About me

I'm Felix Eckhardt, a Senior Full Stack Developer with 25 years of experience building software solutions. Based in Germany, I work as a freelancer helping companies build scalable, user-focused applications.

My journey spans from Java development at Starfinanz to building fraud detection systems processing 54 billion transactions per year at Risk.Ident. I've been a CTO, business owner, and technical lead across various industries including e-commerce, fintech, and health tech.

I believe in starting with WHY — understanding the problem before jumping to solutions. This holistic approach has helped me deliver products that create real business value, like the personalized e-commerce start page that generated a 28% turnover uplift.

Skills & Technologies

KotlinJavaScalaRustPythonTypeScriptSpring BootReactVue.jsSvelteHTMXPostgreSQLKafkaAWSGoogle CloudKubernetesTauriDocker

Education

Diploma Business Informatics

Leuphana University, Lüneburg · Grade A

Languages

German (Native) · English · Spanish

Hobbies

Soldering, Internet of Things

Let's work together

Available for freelance projects, consulting and startup ideas.

eckhardt@rocket-solutions.de
+49 1579 2540876

Rocket Solutions SL

Calle Rio Jucar 66, 03724 Moraira, Spanien

Geschäftsführer / Inhalt: Felix Eckhardt

Tax-Id: ES-B70935150