Available for new projects · remote or on-site

Web applications that carry real business weight.

I'm a freelance full-stack engineer. For eight years I've built the tools companies run on — B2B commerce, sales analytics, dispatch planning, AI tooling. One person, end to end: frontend, backend, deployment.

Tell me about your project See selected work

8+: years shipping software
10: production projects
9: industries served
DE / EN: German native, English C1

Travel Chemical industry Automotive Logistics Construction Performance marketing Manufacturing Sports Productivity

What I do

Custom web applications

Internal tools, portals and platforms built from scratch — Angular or React on the front, NestJS or Spring Boot behind it.

Dashboards & data views

Complex data made usable: large tables, charts, interactive maps, live updates over WebSockets.

APIs & integrations

REST and GraphQL services, microservices, documented with OpenAPI — plus SAP, Mapbox, payment and AI provider integrations.

Taking over existing code

Inherited a codebase nobody maintains? I do framework upgrades, refactoring, test coverage and CI/CD cleanup.

Tech stack

The tools I use daily. Hover a tile to see where I've used it.

Frontend

Angular
React
React Native
TypeScript
JavaScript
Tailwind CSS
SCSS / CSS3
HTML5
RxJS
Next.js

Backend

NestJS
Spring Boot
Node.js
Java / Kotlin
GraphQL
PostgreSQL
MariaDB
OpenAPI

Infrastructure & quality

Docker
Azure
AWS
CI/CD
Cypress
Jest
Nx Monorepo
Git / GitHub

Selected work

Client names stay confidential. Filter by what you need.

2025 — now

Cruise sales application

Travel

A scalable sales platform for a cruise provider: interactive route maps, a standalone CMS so non-technical staff can publish content, and microservices hosted on Azure.

Next.js
React
Tailwind
TypeScript
Mapbox
Azure
OpenAPI

2024 — 2025

B2B e-commerce platform

Chemical industry

Twelve months on a large-scale purchasing platform for a chemical corporation across multiple markets — Angular frontend, NestJS microservices, a redesigned component library, E2E tests and faster CI/CD.

Angular
NestJS
Nx
Docker
Cypress
Highcharts
Azure DevOps

2020 — 2024

Sales analytics platform

Automotive

Four years building and maintaining an analytics platform for international markets: Spring Boot REST APIs, a global design system, dark mode, multilingual UI, admin CMS and microservice rollout on Azure and AWS.

Angular
Spring Boot
PostgreSQL
Hibernate
Tableau
Docker
AWS

2019 — 2023

Digitizing a drywall company

Construction

Built from zero: dashboards, a document management system, a live construction ticker over WebSockets, schedule visualization and time tracking — Angular and Spring Boot on MariaDB.

Angular
Spring Boot
MariaDB
WebSockets
ApexCharts
GitLab CI/CD

2025

AI advertisement analysis tool

Performance marketing

AI pipelines analysing Meta Ads video, image and text via Gemini, OpenAI and Whisper, with the results visualized for marketers. Prompt tuning, tRPC routers, reusable UI.

Next.js
tRPC
OpenAI
Gemini
Meta Insights API
Tailwind

2022 — 2023

Bouldering competition system

Sports

Event, team and live-result management for climbing gyms: an Angular component library, GraphQL against NestJS, real-time results and PWA offline support.

Angular
NestJS
GraphQL
Nx
Docker
PWA

2021 — 2023

Supply-chain risk module

Automotive

A risk management module inside an existing procurement analytics app: AG Grid dashboards for complex risk data, Google Maps for high-risk regions, SAP-backed queries.

Angular
AG Grid
SAP integration
Jenkins
Cypress
Jest

2019

Dispatch planning tool

Logistics

Fleet scheduling with drag-and-drop shipment allocation, real-time updates over WebSockets and dashboards for driver utilization.

Angular
Spring Boot
WebSockets
ApexCharts
Kotlin

2023 — 2024

Time management app

Productivity

An Angular app set up from scratch: chronological calendar view, reusable task components and NgRx state with recurring tasks persisted locally.

Angular
NgRx
PrimeNG
RxJS
date-fns

2018

Android sensor localization app

Manufacturing

A mobile app locating and monitoring Bluetooth sensors in production equipment, with signal-strength visualization for proximity and live data from a Spring Boot backend.

Android
Kotlin
Java
BLE
Spring Boot
REST

About me

I work alone, which means you talk to the person writing the code. No account managers, no handover losses. I take a problem, ask the questions that matter, and come back with something that runs.

Most of my work has been long-term: a sales analytics platform I maintained for four years, a B2B commerce platform across multiple markets, a construction company digitized end to end. I'm comfortable in Scrum teams and equally comfortable being the only engineer in the room.

Clean code, tests and documentation aren't extras I bill separately. They're the reason the second year of a project costs less than the first.

Let's talk

Describe what you need in a few sentences. I'll reply within two working days with an honest read on scope, effort and whether I'm the right fit.

hello@saschariemann.de