I help startups and agencies ship AI features into their apps - without hiring a full ML team.
Senior Flutter & full-stack developer with 5+ years of professional app development, now focused on AI/ML integration. I ship production features - paywalls, ML-powered detection, LLM workflows - into real apps.
Across the stack: Swift/SwiftUI, Kotlin and Flutter on mobile; Python, TensorFlow/Keras, scikit-learn, LangChain, Hugging Face, Transformers, RAG, Model Context Protocol (MCP) and Groq for AI/ML; SQL, Pandas, NumPy and Streamlit for data; TypeScript, FastAPI, Supabase, pgvector, Docker, REST APIs, Telegram bots and cloud deployment on the backend; RevenueCat, StoreKit, Google Play Billing and Intercom for monetization and tooling; and Figma, Photoshop and Lightroom for design.
About me
Hi, I'm Boris - a freelance developer based in Berlin. I've been active online for almost 20 years: first as a photojournalist and blogger, then with my own websites, projects, and countless commissions and collaborations. Two intensive bootcamps - a 12-month app developer program and the AI bootcamp at Le Wagon - turned that long-time hobby into my profession and reignited my passion for building. What clients value most: clear communication, reliable deadlines, and solutions that work in the real world.
AI/ML IntegrationAdd machine learning models and intelligent features to your existing mobile or web app.from €2,500/week
LLM/RAG & AI AgentsAI agents, RAG pipelines, semantic search, and eval-driven LLM features.from €2,500/week
Custom Mobile AppsNative iOS, Android, or cross-platform Flutter apps - from concept to App Store.day-rate from €600
Data Pipelines & AutomationScraping, ETL, scheduled jobs, and API integrations.day-rate from €600
Telegram Bots & AutomationCustom Telegram bots - from LLM-powered chat assistants to keyword alerts, scheduled notifications, and channel monitoring.from €1,500
Prototyping & MVPsQuick proof-of-concept builds to validate your idea before committing to full development.day-rate from €600
AI for Non-Profits & Public Sector
For charitable organizations, associations and publicly funded projects (AMIF, ESF+, BAMF, foundations) I set up AI-powered knowledge bases and chatbots that answer only from reviewed content - GDPR-compliant, hosted in the EU, and maintainable by your own team without programming skills.
Knowledge base + RAG chatbotPostgreSQL/pgvector, LLM via API, answers with source references and a clear "I don't know" fallback instead of guessing.
Privacy by designEU hosting, no user accounts, no training on your data, technical documentation prepared for the data-protection review.
Enablement of your teamEditorial interface without SQL, training for non-technical staff, handover documentation that also serves grant audits.
Integration instead of custom buildsManaged services and open source, vendor-independent, every component replaceable, MCP-ready for future integrations.
Procurement-friendlyHourly rate for funded projects on request, time sheets per activity, invoice with German VAT, references and work samples available.
Interactive dashboard analyzing German police assembly data - visualizing patterns, trends, and statistics across thousands of registered public gatherings.
Interactive database of all "Die drei ???" episodes, featuring 1,977 characters, a Rocky Beach city map, statistics, and visualizations across the entire series.
Lightweight iOS & Android app that ingests Berlin assembly-authority data and shows demonstrations, rallies, and vigils in a calendar. 2,300+ active users.
A film archive that tracks recently deceased actors and shows what percentage of each movie's cast and crew have already passed away. Built with data from Wikidata and TMDB, stored in PostgreSQL.
A Telegram bot that scans German supermarket flyers and sends personalized vegan deals twice a week. Users set their postal code to receive discounts with product images and store locations.
References
We're a family business of more than 80 years, and honestly we were unsure about the whole internet thing. Boris understood from day one how sensitive our field is. Our outdated site became a modern, dignified presence - looking just as good on a phone as on a desktop. He kept to deadlines, explained everything without jargon, and was there instantly for questions. We've had plenty of compliments ever since.
– Friedhofsgärtnerei und Gartenbau Meyer
We have always been very satisfied with Mr. Niehaus's work. He is committed, curious, and open to new perspectives within the team.
– Management, app startup (from the employment reference, 03/2026)
As the first employee in the app division, Mr. Niehaus is responsible for building this app … successful release of the app in both app stores.
– Management, app startup (from the employment reference, 03/2026)
GitHub Activity
20252026
How we work
1 · Intro callA free, no-obligation 15-min call. We talk through your idea, goals, and budget.
2 · Fixed proposalYou get a clear scope, timeline, and a fixed price - no surprises.
3 · Weekly demosI build in short cycles. You see working progress every week and can steer.
4 · HandoverYou receive the finished product and own all the code. Support afterwards on request.
FAQ
What does a project cost?
It depends on scope. After a short call you get a fixed-price proposal so you know the cost upfront. Day-rate and monthly retainer options are available too.
How soon can you start?
Immediately. I'm a full-time freelancer and can usually start within a week of agreeing on scope.
How does billing work?
You get a proper invoice (German VAT where applicable). I work with multiple clients, so there's no false self-employment risk.
Do you work with non-profits and public institutions?
Yes. I work as a freelancer for charitable organizations and publicly funded projects, provide hourly rates and time sheets for grant reporting, and deliver GDPR-compliant solutions hosted in the EU. Invitations to submit offers (e.g. under § 50 UVgO) are welcome.
Is Boris Niehaus available for freelance projects?
Yes - Boris works full-time as a freelance developer and is available immediately. He takes on AI/ML integration, custom mobile and web app development, prototyping, and data pipeline projects.
What kind of apps does Boris Niehaus build?
Boris builds native iOS apps (Swift/SwiftUI), Android apps (Kotlin), and cross-platform apps with Flutter. He specializes in adding AI and ML features such as LLM-powered chatbots, computer vision, ML-based recommendations, and RAG pipelines.
Where is Boris Niehaus based?
Boris Niehaus is based in Berlin, Germany. He works on-site in Berlin and remotely across the EU timezone.
What AI and machine learning technologies does Boris work with?
Boris works with Python, TensorFlow, Keras, scikit-learn, LangChain, Hugging Face Transformers, and RAG. He completed Le Wagon's 7-month Data Science & AI Bootcamp.
Get in Touch
Available immediately · day-rate or project-based · remote across the EU.
Engagement: Telegram bots from €1,500 · AI feature sprint from €2,500/week · day-rate from €600. Fixed-price packages or monthly retainer - whatever fits your project.
Boris Niehaus is a freelance mobile app developer and AI integration specialist based in Berlin, Germany.
With 5+ years of professional app development experience and a 7-month Data Science and AI Bootcamp at Le Wagon,
he builds mobile apps with intelligent features - from ML models to LLM-powered workflows.
Available for freelance projects in Berlin, Germany, and remote across the EU.
Services: AI/ML integration, LLM/RAG-powered features, custom Flutter/iOS/Android apps, data pipelines, prototyping and MVPs.
For non-profits and the public sector: GDPR-compliant AI knowledge bases and RAG chatbots on PostgreSQL/pgvector, hosted in the EU, with editorial interfaces for non-technical teams, documentation for grant audits, and hourly rates for funded projects (AMIF, ESF+, BAMF).
Freiberuflicher KI-Entwickler in Berlin für gemeinnützige Träger und öffentliche Hand: DSGVO-konforme Wissensdatenbank, RAG-Chatbot, Datenschutz, EU-Hosting, Befähigung nicht-technischer Teams, Stundensatz für Förderprojekte.
Tech stack: Swift, SwiftUI, Kotlin, Flutter, Python, TensorFlow, scikit-learn, LangChain, Hugging Face, RAG, SQL, Pandas, Supabase, Docker.
