
Kai k.
Level 1
Senior Software Engineer
Skills

See my services


Want to work on an hourly basis?
Tell Kai k. what you need.
$24
/
hourPortfolio
Work experience
CEO
Developer Tag • Self-employed
Sep 2025 - Present • 8 mos
Founder & CEO with a strong engineering background and hands-on development experience, leading a small, high-performing team of developers. I actively contribute to system architecture, core development, and technical decision-making while overseeing delivery and quality. My team is capable of building fast, scalable, and affordable products without compromising on performance, security, or maintainability. We specialise in SaaS platforms, enterprise web applications, AI-driven automations, and custom CRM systems, delivering solutions that align closely with business goals. I combine technical execution with leadership, ensuring projects move quickly from concept to production with clear communication, realistic timelines, and cost-effective delivery.
Lead Software Engineer
Programmers • Full-time
Jul 2023 - Oct 2025 • 2 yrs 3 mos
1) Own system architecture for biometric verification workflows (KYC, AML, identity matching) 2) Lead design decisions for high-throughput, low-latency systems 3) Review and approve technical designs, PRs, and deployments 4) Enforce engineering best practices (security, testing, performance) mplement secure-by-design systems for biometric data 5) Ensure compliance with GDPR, ISO 27001, SOC 2, and RegTech standards 6) Oversee data encryption, access controls, and audit logging
Senior Software Engineer
JOIN Solutions Gmbh • Part-time
May 2022 - Apr 2025 • 2 yrs 11 mos
Spearheaded the development of features that maximize revenue by 30%. Optimized existing codebase, resulting in a 25% improvement in application performance. Implemented automated testing protocols, reducing bug reports by 40% Architected and led the development of scalable, high-performance web applications using modern JavaScript frameworks (React.js, Next.js) and backend services (Node.js, Express). Oversaw CI/CD pipeline implementation (GitHub Actions, Jenkins) to streamline deployment workflows and reduce release cycles. Collaborated with UI/UX designers to build responsive, accessible interfaces using Tailwind CSS and componentbased architecture. Led microservices-based backend design, utilizing RESTful APIs and optimizing database interactions with MongoDB and PostgreSQL. Spearheaded code quality assurance via automated testing (Jest, Cypress) and enforced TypeScript standards across the codebase.
17 Reviews
| (17) | ||
| (0) | ||
| (0) | ||
| (0) | ||
| (0) |
Rating Breakdown
- Seller communication level
- Quality of delivery
- Value of delivery
Sort By

ryanwalker007
Repeat Client

United States
Very reliable and easy to work with. Understood the requirements clearly and delivered on time. The solution was clean and worked as expected. I would say it's a 10/10 service
tommy_johnn2
Repeat Client

United Kingdom
Mikael handled the project efficiently and communicated clearly. Everything was delivered on time and worked as expected. He is BEST one I ever meet on Fiverr
brown1865

United States
Good attention to detail. Identified the validation bug and fixed it properly instead of applying a quick patch. Reliable developer with solid backend knowledge.
alex_morganz
Repeat Client

United States
Quick, efficient, and very reliable. Good experience overall.
tommy_johnn2
Repeat Client

United Kingdom
Very solid developer. Took ownership and handled everything properly. 10/10 Recommended


