Senior Full Stack Engineer
Senior Full Stack Engineer & Technical Architect Helping Global Enterprises Build Scalable, Secure SaaS Platforms That Cut Costs, Boost Revenue & Pass Compliance.
- ✓Built systems processing 45M transactions/day
- ✓Reduced API latency by 3x
- ✓Led zero-downtime migrations
Let's Build Something Great Together.
You have the vision, I have the expertise. Let's build a fast, reliable app that delights your users and grows your business.
About Me
My Journey
Senior Full Stack Engineer with expertise in Spring Boot, Node.js, React.js, and event-driven microservices. Experienced in designing and developing scalable, cloud-native solutions on AWS, Azure, and GCP.
I've had the privilege of working with international teams across Norway, Japan, and the USA, delivering critical systems for companies like NTB, Rakuten, and various fintech organizations. My expertise spans from microservices architecture and event-driven systems to DevOps practices and performance optimization, always focusing on clean code and maintainable solutions.
With over 6 years of experience in full-stack development, I specialize in creating robust, scalable applications using Java, Spring Boot, React, and modern cloud technologies. Skilled in TDD, clean code architecture, CI/CD automation, and contributing to key technical decisions.
International Experience
Worked with clients across Norway, Japan, USA, and Bangladesh
Performance Expert
Optimized systems achieving 3x performance improvements
Technical Leadership
Mentored junior engineers and led technical decisions
Clean Architecture
Expert in TDD, SOLID principles, and design patterns
Professional Experiences
6+ years of experience building enterprise-grade systems for international clients
Developed NTB's Image Portal and Billing System (Spring Boot, Stripes, JSP, React.js). Requirement analysis, design, and collaboration with international teams. Implemented CI/CD pipelines on AWS.
Full Stack Developer for Core System, Document Signing, and AML solutions (Scala, Lift, Spring Boot, PostgreSQL). Database design with normalization, indexing, and query optimization.
Migrated Rakuten Beauty (E-commerce) from PHP to Java; backend and DevOps in private cloud. Built event-driven microservices using Kubernetes, Helm, Redis, GraphQL, Elasticsearch, Logstash, Kibana, Grafana.
Built low-code/no-code platform with event-driven microservices (Micronaut, Flask, NodeJS, Flutter, GCP, AI/ML). Practiced DDD, TDD (90%+ coverage), clean code, SOLID, DRY, KISS.
Key contributor in BKASH AML360 and BKASHSIS with microservices (Spring Boot, Angular, MySQL, MongoDB). End-to-end SDLC: requirements, design, backend, database modeling, deployment. Implemented caching with Redis, JWT authentication, and TDD.
Professional Projects
Enterprise-grade systems built for international clients across various industries
Developed NTB's Image Portal (bilder.ntb.no), Norway's leading media asset management platform serving news organizations and creative professionals. Built a scalable SaaS solution with microservices architecture for storing, organizing, and distributing millions of images and videos. Implemented advanced search capabilities using AWS OpenSearch and integrated billing systems for subscription management. Collaborated with international teams on requirements analysis, system design, and deployment. The platform handles high-volume media assets with efficient search and retrieval capabilities.
Key Achievements:
- 3x faster search performance with AWS OpenSearch
- Scalable microservices architecture
- AWS cloud deployment
Technologies:
Developed Visena's comprehensive office management SaaS platform (https://my.visena.com/visena/origo/nb_NO/home) for lawyers and accountants. Features include Core System, Document Signing, compliance, AML solutions, Database design with normalization, indexing, and query optimization.
Key Achievements:
- Full AML compliance system
- Document signing workflow
- Multi-tenant architecture
Technologies:
Key contributor to the migration of Rakuten Beauty's $200M/year e-commerce platform from legacy PHP to modern Java microservices architecture. Worked as part of a 15-member team and directly mentored 2 junior engineers.
Key Achievements:
- 3x API performance improvement
- Mobile-first GraphQL services
- Zero-downtime migration
Technologies:
Low-code/no-code platform with event-driven microservices. Implemented DDD patterns and achieved 90%+ test coverage with comprehensive AI/ML integration. Built low-code/no-code platform with event-driven microservices (Micronaut, Flask, NodeJS, Flutter, GCP, AI/ML). Practiced DDD, TDD (90%+ coverage), clean code, SOLID, DRY, KISS.
Key Achievements:
- Reusable CRUD library
- 90%+ test coverage
- Event-driven architecture
Technologies:
Anti-money laundering system handling millions of transactions daily. Built scalable microservices architecture with real-time monitoring and compliance reporting. Key contributor in BKASH AML360 and BKASHSIS with microservices (Spring Boot, Angular, MySQL, MongoDB). End-to-end SDLC: requirements, design, backend, database modeling, deployment. Implemented caching with Redis, JWT authentication, and TDD.
Key Achievements:
- Spearheaded end-to-end development of enterprise AML solution from concept to production
- Engineered scalable microservices architecture processing 10M daily transactions
- Designed comprehensive database ecosystem for high-volume financial data monitoring
- 200% KPI achievement
Technologies:
Malicious user screening engine processing high-volume transactions. Implemented advanced algorithms for real-time user behavior analysis and risk assessment. Key contributor in BKASH AML360 and BKASHSIS with microservices (Spring Boot, Angular, MySQL, MongoDB). End-to-end SDLC: requirements, design, backend, database modeling, deployment. Implemented caching with Redis, JWT authentication, and TDD.
Key Achievements:
- 40-45M daily records screening
- Real-time fraud detection
- Advanced ML algorithms
Technologies:
Client Testimonials
Hear what industry leaders have to say about working with me
Senior Software Engineer, Agoda | Ex-TL: DataSoft, DataSoft Systems Ltd | BD
"Shahriar joined Datasoft in one of the projects which I was the tech lead of. During this time, Shahriar showed tireless determination and commitment to his duties and responsibilities. He was always willing to learn new things and share knowledge with colleagues. From his seniors, he always looked for feedback and areas on which to improve. I wish him all the best for the future."
Principal Software Engineer, BJTI Inc | Rakuten Inc. | Japan
"Md. Shahariar Hossen is a hard working, curious minded, challenge seeking developer and a fantastic colleague to work with. From his position he always try to give his best in any project he works on. I will always wish him great success in his future endeavour."
Software Engineer, UDPlatforms Inc | USA
"Md. Shahariar Hossen is one of my ex colleagues that I found sincere, hard working, knowledgeable. His can do mentality is always a key feature that I found helpful for the team. I'd definitely recommend him to any team which embraces challenges, knowledge sharing and leadership."
Why Choose Me Over Other Senior Engineers?
Your platform won’t crash during Black Friday or product launches.
Avoid $5M+ regulatory fines — I’ve shipped compliant systems used by millions.
No lost revenue while upgrading legacy systems.
Reduce technical debt, lower maintenance costs, onboard devs faster.
CI/CD pipelines, monitoring, alerting — so your team stops firefighting.
Results That Speak Volumes
"For Rakuten: Migrated $200M/year e-commerce platform in 10 months — with zero customer complaints."
"For BKASH: Built anti-money laundering systems processing 45M transactions daily — achieving 200% of KPI targets."
"For NTB: Improved media search performance by 3x using AWS OpenSearch — reducing query time from seconds to milliseconds."
Skills
Comprehensive expertise across the full technology stack with focus on scalable, maintainable solutions
Certifications & Training
Advanced security practices for Java applications
View CertificateAdvanced Java programming and best practices
View CertificateFundamental Java programming concepts
View CertificateAzure cloud infrastructure and administration
View Certificate500-hour comprehensive machine learning program
500 hrGet In Touch
Ready to discuss your next project? Let's build something amazing together.
I'm always interested in new opportunities and exciting projects. Whether you need a senior developer for your team or want to discuss a consulting project, I'd love to hear from you.
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