Markus Olsson
Senior Backend Developer | Java Specialist | Performance & Scalability Expert
Building robust, high-performance backend systems and solving complex problems.
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I'm a seasoned backend developer with a deep passion for technology that started at age 10 with HTML and JavaScript. My journey has taken me through C++ game programming to specializing in high-performance Java backend systems, often tightly integrated with databases for optimal data handling.
Programming isn't just my job; it's a core hobby I enjoy both professionally and personally. I thrive on challenges, particularly dissecting complex problems to architect elegant, efficient solutions. Designing and optimizing applications for demanding performance requirements is where I truly excel.
I'm a quick learner, readily adapting to new technologies and systems. I also value collaboration and enjoy mentoring others, sharing knowledge, and helping teams grow.
While I enjoy collaboration, I prefer focused work over days filled with meetings lacking clear outcomes. My strength lies in building functional and performant systems; I'm less focused on fine-tuning visual details ("pixel pushing") and appreciate collaborating with design experts for that aspect.
Strengths & Philosophy
Innovative Problem Solving
I excel at analyzing problems and devising solutions others might overlook. I don't just build what's asked; I explore better ways to achieve the underlying goal.
Example: Tasked with finding duplicate accounts via fuzzy name matching, I delivered that but also developed a novel IP analysis tool. This tool correlated login IPs and frequency, proving significantly more effective in identifying suspicious account linking – a solution nobody asked for but which became invaluable.
Backend Performance Design
My deep understanding of database internals and system architecture allows me to design backend systems optimized for speed, scalability, and reliability, capable of handling thousands of transactions per second.
Teaching & Mentoring
I genuinely enjoy helping colleagues and teams understand complex technical concepts, whether through formal training (like the Java Academy I ran) or informal support and knowledge sharing.
Proactive System Analysis
I have a track record of identifying and resolving critical performance bottlenecks, sometimes through unconventional analysis, like diagnosing a client-side infinite loop that was crippling a multi-million GBP support tool by observing browser behavior alone.
Work Experience
- Key member of a small backend team managing two high-traffic online casino platforms.
- Independently developed and maintained critical microservices including Search (BO-Search), Bonus Engine, Game Statistics Aggregation (handling 250M+ transactions), Session Management, High-Speed Transaction Cache, Third-Party Analytics Tracking, and German Regulatory Compliance systems.
- Built and operate a 24/7 performance testing tool ensuring platform stability under continuous load.
Java Spring Boot ElasticSearch Kafka MongoDB Redis AWS Gradle Keycloak CI/CD
- Joined during a microservices transition; pivoted to focus heavily on improving Developer Experience for front-end teams struggling with the initial backend design.
- Acted as the primary backend liaison for multiple front-end teams, providing daily support and troubleshooting.
- Developed custom tooling to streamline local development and service interaction for front-end developers.
- Contributed to backend feature development for my assigned team.
- Conducted Java training sessions for developers.
Java Spring Microservices REST Jenkins Maven
- Product Integration: Built robust game provider integrations, focusing on API design, stability, and creating shared components to accelerate new integrations.
- Bank Team: Optimized the core wallet system handling thousands of TPS.
- Customer Team: Developed customer management systems and implemented regulatory features.
- DevOps: Configured and managed Splunk & AppDynamics; provided log analysis support and custom AppDynamics instrumentation.
- Training Lead: Ran the Java Academy (Stockholm/London) and Tech Training for non-technical staff (Malta).
- Special Projects: Analyzed and diagnosed critical performance issues in a 10M GBP customer support tool, preventing its replacement. Organized and spoke at tech meetups.
- Part of the technical group evaluating Spring Boot adoption.
Java Spring Glassfish Oracle DB Splunk AppDynamics SOAP REST ActiveMQ Solace Hibernate JPA
- Developed a back-office system for a poker site, integrating multiple payment solutions.
Java JSF MySQL
- Co-founded a startup game studio post-graduation.
- Developed game prototypes and mechanics using C# and C++.
C++ C# Game Development
Technologies & Skills
Personal Projects
Developed a web application (Spring Boot/Thymeleaf backend, JS frontend) deployed via Docker on AWS with MySQL, designed for SFI students (Swedish for Immigrants) to practice grammar on mobile devices, addressing a need identified by my father, an SFI teacher.
Visit Live SiteCurrently rebuilding Skriv Svenska as a standalone mobile/web application using Dart and Flutter. The goal is to create a self-teaching tool with integrated AI for multi-language support and instructions.
Visit Dev Preview (Note: Free tier, may spin down)Smaller Utility Projects
I often build small tools for personal use, demonstrating practical application of various technologies. Examples include:
- A private React-based web app for my son's star-reward system.
- A native Android app (personal use only) to scan online marketplaces and alert me for specific Magic: The Gathering cards below a target price.
Speaking & Community
I believe in sharing knowledge and contributing to the tech community. I have presented at:
- Local Development in a Cloudy World (Meetup Group Organizer & Speaker)
- ELK with Spring Boot in the Cloud (Meetup Speaker)
- Hybrid Rendering (Meetup Speaker)
- JCrete 2015 Unconference (Discussion Driver: Microservices)
Education
Programmer, Game Programming - Intensive C++ game development training (8+ hours/day).