A. Ruben Kandel | Osiris-Team

Senior Backend Developer & Tech Lead
Senior Backend & Tech Lead

Senior Backend Developer & Tech Lead

White-label capacity for IT agencies and a holistic IT partner for SMEs. Software Development, ERP/CRM modernization, API integrations, and architecture guidance.

Milestone & Feedback-driven German & English Weekly review calls
For agencies: Backend capacity For companies: Modernize IT & processes

Industries & Business Domains

I would like to expressly thank you for your commitment. The software has decisively and sustainably simplified our daily work. We have become much more efficient and therefore more effective, thorough, transparent, and accurate. Thank you very, very much for that. - Dorina, Germany
Really enjoyed working with him, put a lot of effort into the work and solved all my issues. Really recommend working with him and would love to work with him again in the future! - Jack, Australia
Why Work With Me

Senior Tech Expertise Without Overhead

Direct, partnership-based collaboration at senior level, pragmatic, transparent, and without unnecessary management layers.

Book a meeting
Direct collaboration with a single developer
1

One Direct Point of Contact (Tech Lead)

No "broken telephone" through project managers. You communicate directly with the developer who designs the system architecture and writes the code. Decisions stay fast and clear.

2

100% Code Ownership & IP Rights

From day one you get full access to the Git repository. All usage and copyright (IP) rights transfer completely to you. No hidden dependencies (vendor lock-in).

Thoughtful, accountable execution from a personal partner
3

Efficient Cost Structure (€80/hr)

Because I don't have to cross-finance agency overhead (sales, offices, management) as an independent senior developer, you invest your budget 100% in productive code and clean architecture.

4

Full Lifecycle: From Architecture to Go-Live

I don't just handle development, I accompany the entire setup: server infrastructure (Hetzner, AWS, Docker), databases, CI/CD pipelines, and a smooth go-live.

A steadier, more practical working rhythm
5

Long-Term Partnership

After go-live, I remain flexibly available as your external tech lead for training, maintenance, hosting support, security updates, and scaling.

6

Pragmatism Instead of Over-Engineering

From experience with complex ERP and logistics systems, I know: the best software solves a business problem without creating unnecessary technical complexity.

Contact

Ways to work with me

Two clear models: white-label delivery for agencies, end-to-end modernization for companies.

White-Label

For Agencies

Backend capacity as your subcontracted senior developer and tech lead.

  • Flexible weekly capacity, hours or days
  • Java, Spring Boot and APIs
  • Delivery under your brand
  • Code reviews on request
Build & Run

For Companies

Modernize IT and processes end to end, from architecture to operation.

  • Legacy ERP/CRM modernization
  • API and third-party integration
  • Architecture and CTO consulting
  • Custom software development
Services & Process

Why businesses choose me

Milestone- and feedback-driven, with a weekly review call as the product evolves.

Criterion With me Classic IT system house Typical offshore outsourcing
Point of contact 1 Senior Tech Lead (direct) Project manager (as intermediary) Developers (often language barriers)
Quality level High quality code Mixed teams (seniors & juniors) Highly fluctuating code quality
Source code & IP Copyright Transfer Often tied to system-house solutions Unclear copyright
Go-live & hosting End-to-end support Usually expensive support contracts Often ends at code handover
Hourly rate €80 (transparent & efficient) ~€120 – €180+ €30 – €60
Core stack Java Spring Boot REST APIs Webhooks SQL Docker Business Central (AL) Vue React
Development Approach

Traditional Code or AI-Powered Development?

Your choice: 100% manual programming or maximum speed with AI Agent Swarms. As your tech lead, I adapt to your requirements, budget, and compliance rules. Architecture and code reviews always stay with me.

Manual & Deterministic

Traditional Development: 100% Manual Code

Strict compliance, legacy systems & confidentiality.

The Process

Every line of code is written manually by me. No generative AI, no data leaves your systems.

Ideal for
  • Highly regulated industries (e.g., medical technology, fintech)
  • Legacy system refactoring (Business Central/Navision)
  • Strict confidentiality requirements (zero data retention)
Advantages
  • Maximum control, full compliance with your IT security policies

Limitations: Slower time-to-market and higher project costs.

AI-Accelerated

AI Agent Swarms: Maximum Speed

Radical speed, efficiency & fast time-to-market.

The Process

A network of AI coding agents (swarms) writes boilerplate code, tests, and standard features. I steer the prompts, orchestrate the output, and audit everything.

Ideal for
  • Agencies needing fast white-label capacity
  • Startups and MVP development
  • Greenfield API integrations
Advantages
  • Significant cost and time savings. More features in the same time

Limitations: Requires modern tech stacks (e.g., Spring Boot, Vue/React) and approval for AI processing of anonymized code.

My Promise as Senior Tech Lead

AI is a scaling tool for me, not a replacement for expertise. Even if a swarm generates thousands of lines in seconds, I review every decision, run strict code reviews, and guarantee a secure, maintainable product. The responsibility stays with me.

Frequently Asked Questions

Do you work white-label for agencies?

Yes. I work as a subcontracted senior backend developer & tech lead under your brand, on a flexible availability retainer (fixed hours or days per week).

How is pricing structured?

Agencies book a weekly retainer. Companies get a “Build & Run” model: a fixed price for architecture & development plus a monthly flat rate for cloud hosting & maintenance.

How does the process work?

Milestone- and feedback-driven: we hold weekly review calls so the software evolves with your real requirements instead of rigid early specifications.

Which languages do you speak?

I communicate fluently in German and English (plus Portuguese and Turkish).

Read the full contract FAQ →