// custom software · saas · consulting
Custom software, from first idea to production.
callbk is a software engineering studio from Germany. We design, build, and operate web applications, SaaS products, and MVPs — for startups and enterprises.
// 01 — services
What we do
From the first idea to a running system — we cover the entire development process.
Custom Software Development
Tailored web applications and enterprise systems for requirements that off-the-shelf software cannot cover.
SaaS Products
Scalable cloud applications on AWS — from the first architecture decision to live operation.
PoCs & MVPs
Working prototypes and minimum viable products in weeks, so you can validate before you invest.
Technology Consulting
Independent advice on architecture, stack, and build-vs-buy decisions — for startups and product teams.
// 02 — proof of work
We build and run our own SaaS.
finlight.me is our financial-news API platform — designed, built, and operated in production by callbk. It is the same engineering we bring to client projects.
finlight.melive in production
A real-time financial news API with advanced filtering, AI-powered sentiment analysis, and multiple integration options.
Real-Time Data
Live financial news via REST, WebSocket & webhooks
AI Analysis
Sentiment analysis and entity tagging
Smart Filtering
Powerful query and filter system
Developer-Friendly
Easy integration with comprehensive APIs
// 03 — how we work
A process without surprises
Direct communication, senior engineers, working software early. This is how every callbk project runs.
- 01
Discover
We start with your domain, not with code: goals, users, constraints, and what success looks like.
- 02
Design
Architecture, stack, and scope — a clear technical plan with honest effort estimates before anything is built.
- 03
Build
Short iterations with working software you can click through from the first weeks — no black-box development.
- 04
Operate
We deploy to your cloud or ours, monitor it, and keep evolving the product after launch.
// 04 — solutions
What we deliver
From new SaaS products to integrations with the systems you already run.
Cloud-Native Applications
Scalable web applications built with modern frameworks and deployed on AWS — serverless where it makes sense.
- Next.js
- NestJS
- Lambda
- Auto-scaling
Business Intelligence Tools
Custom dashboards and analytics platforms that turn your data into decisions.
- Real-time Data
- Custom Charts
- Export Tools
- Mobile Ready
Enterprise Integration
Connect existing systems with modern APIs, automate workflows, and modernize legacy software step by step.
- API Design
- System Integration
- Automation
- Legacy Modernization
// technologies we work with
- TypeScript
- JavaScript
- Java
- React
- Angular
- Next.js
- NestJS
- Spring Boot
- Node.js
- PostgreSQL
- Docker
- AWS
- Serverless
- Tailwind CSS
- SST
// 05 — about callbk
Direct lines, no hand-offs
Every callbk project is delivered by senior engineers who own it end to end. You always have a direct line to the people writing your code.
Engineering-led
callbk is run by engineers, not by a sales layer. The people you plan your project with are the people who architect and build it.
End-to-end ownership
Architecture, development, cloud deployment, and operations come from one team — no hand-offs, no lost context.
Based in Germany
Located in Ludwigshafen, working remote-first with startups and enterprises. GDPR-native by default — like this website.
// 06 — contact
Let's talk about your project
Tell us what you're building. We usually reply within one to two business days.
One email is enough
No contact forms, no cookies, no tracking — just write to bartsch.buyukkakac@gmail.com.