Matej Jelluš
Fractional CTO | Tech Leader | Engineering Mentor
I help Startups and Scaleups to build and scale their products and engineering teams.
12+ years building and scaling SaaS products. Former CTO at Slovakia's fastest-growing tech company (Deloitte Fast 50). Now helping startups and developers make better technical decisions.
First call is completely free - no commitment required
1-on-1 Mentoring for Mid to Senior Developers
Feeling stuck in your career? Unsure about your next technical decision?
As a former CTO who scaled teams and products, I've mentored dozens of developers through their toughest challenges. Whether you're aiming for a senior role, architecting your first major system, or navigating complex technical decisions, I'll help you get there faster.
What You'll Get:
- Career Growth Strategy - Clear path from mid-level to senior or staff engineer
- Technical Decision Validation - Sanity check your architecture before you build it
- Real-World Problem Solving - Work through your actual day-to-day challenges together
- Leadership Skills - Learn to influence without authority and drive technical initiatives
- Interview Preparation - Get ready for senior/staff engineer interviews with confidence
Technologies I specialize in: Node.js, React, TypeScript, AWS, Kubernetes, System Design, Event-Driven Architecture
Don't just take my word for it:
"Matej's mentorship helped me land a senior position. His practical advice on system design was game-changing."
- Mid-level Developer → Senior Engineer
Real Impact, Real Results
Occasional speaker at tech meetups and podcasts, sharing insights on knowledge management, team scaling, and building resilient engineering cultures. Featured at WebUP meetup discussing Bus Factor and Knowledge Share, at Sapie I talked about technical Challenges of a Growing Company, and as a guest on the 0101 tech podcast.
Beyond consulting engagements, I actively contribute to the tech community through speaking, mentoring, and sharing real-world lessons from scaling products and teams.
Kontentino
CTO RoleSlovakia's two-time fastest growing tech company (Deloitte Fast 50)
⚠️ The Challenge
Regular product downtimes, performance issues, and a 3-person team with zero processes or automation. Global expansion was impossible with the current infrastructure.
🔧 The Solution
- Migrated entire product from local servers to AWS cloud (EKS, CloudFront CDN)
- Grew team from 3 to 12 developers + 2 QA testers
- Implemented 2-week sprints with automated testing & deployment
- Built comprehensive monitoring and alerting system
✅ The Impact
- ✓ Near-zero downtime on landing pages
- ✓ Dramatically improved UX for global users
- ✓ 4x team growth with smooth processes
- ✓ Global reach enabled by CDN distribution
BonusQR
Mentor RoleLoyalty system platform empowering retailers
⚠️ The Challenge
Australian clients experiencing extremely slow loading times and laggy updates. Poor global performance was damaging user satisfaction and threatening international expansion.
🔧 The Solution
- Strategic mentoring sessions on product development and go-to-market strategy
- Diagnosed and fixed CDN configuration to leverage edge locations
- Enhanced UX with loading states for better perceived performance
- Implemented optimistic updates for instant user feedback
✅ The Impact
- ✓ Significantly faster load times globally
- ✓ Improved user satisfaction in Australian market
- ✓ Better UX perception with instant feedback
- ✓ Enabled expansion to international markets
Introduction Call
Free
30-minute consultation
Discuss your motivation
Review current situation
Identify key challenges
Define clear goals
Zero commitment • Zero pressure
Fractional CTO
Custom
For Startups & Scaleups
Free 30-min introduction call
Development process optimization
Strategic technical guidance
AWS & cloud infrastructure
Product scaling strategy
Architecture design & review
Team building & hiring support
1-on-1 Mentoring
€50/h
For Mid to Senior Developers
Free 30-min introduction call
Career growth strategy & guidance
Technical decision validation
Real-world problem solving
System design & architecture review
Interview preparation
Ready to Get Started?
Book your free 30-minute consultation. No sales pitch - just honest advice about your situation.
Book Your Free Call NowUsually respond within 24 hours • Flexible scheduling • All timezones welcome