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I'm a Senior Full Stack Engineer with over 14 years of experience building and scaling software across fintech, e-commerce, SaaS, and healthcare. I specialize in cloud-native systems, microservices, and modern web frameworks like React, Next.js, and .NET Core. I've led cross-functional teams, improved system performance by up to 50%, and delivered secure, GDPR-compliant solutions. I'm also experienced in mentoring engineers, optimizing delivery pipelines, and driving architectural modernization to help businesses scale reliably.…I'm a Senior Full Stack Engineer with over 14 years of experience building and scaling software across fintech, e-commerce, SaaS, and healthcare. I specialize in cloud-native systems, microservices, and modern web frameworks like React, Next.js, and .NET Core. I've led cross-functional teams, improved system performance by up to 50%, and delivered secure, GDPR-compliant solutions. I'm also experienced in mentoring engineers, optimizing delivery pipelines, and driving architectural modernization to help businesses scale reliably.

Dmitriy Apolonov

Full Stack Developer, Web Developer, Front-End Developer, +2

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I'm a Senior Full Stack Engineer with over 14 years of experience building and scaling software across fintech, e-commerce, SaaS, and healthcare. I specialize in cloud-native systems, microservices, and modern web frameworks like React, Next.js, and .NET Core. I've led cross-functional teams, improved system performance by up to 50%, and delivered secure, GDPR-compliant solutions. I'm also experienced in mentoring engineers, optimizing delivery pipelines, and driving architectural modernization to help businesses scale reliably.…I'm a Senior Full Stack Engineer with over 14 years of experience building and scaling software across fintech, e-commerce, SaaS, and healthcare. I specialize in cloud-native systems, microservices, and modern web frameworks like React, Next.js, and .NET Core. I've led cross-functional teams, improved system performance by up to 50%, and delivered secure, GDPR-compliant solutions. I'm also experienced in mentoring engineers, optimizing delivery pipelines, and driving architectural modernization to help businesses scale reliably.

Available to hire

I’m a Senior Full Stack Engineer with over 14 years of experience building and scaling software across fintech, e-commerce, SaaS, and healthcare. I specialize in cloud-native systems, microservices, and modern web frameworks like React, Next.js, and .NET Core.

I’ve led cross-functional teams, improved system performance by up to 50%, and delivered secure, GDPR-compliant solutions. I’m also experienced in mentoring engineers, optimizing delivery pipelines, and driving architectural modernization to help businesses scale reliably.

Skills

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Expert

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Intermediate

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Work Experience

Senior Full Stack Engineer at Zalando

May 1, 2025 - May 1, 2025

Spearheaded modernization of Zalando's e-commerce platform with React, Next.js, and Svelte, delivering a 35% increase in user engagement. Built scalable GraphQL/Elasticsearch search architecture reducing search latency by 50% and boosting product discoverability. Integrated secure payment flows and GDPR-compliant customer data handling using JWT, Auth0, and encryption libraries. Automated CI/CD pipelines with GitHub Actions and Kubernetes, enabling daily production releases with near-zero downtime. Designed and implemented observability stack (Prometheus, Grafana, Datadog) for real-time monitoring. Partnered with product teams to implement personalized recommendation engines, increasing conversion by 15%. Mentored 6 junior engineers, introduced coding standards, and organized weekly architectural review sessions.

Senior Software Engineer at Spotify

September 1, 2023 - September 1, 2023

Designed a microservices migration roadmap for client onboarding, reducing onboarding time by 40%. Built REST/GraphQL APIs handling 500K+ daily transactions across multiple regions. Strengthened security posture by integrating OAuth2.0 and SAML, reducing unauthorized access by 95%. Implemented automated A/B testing pipelines for real-time feature validation and data-driven decisions. Re-architected data ingestion pipelines with Spark Streaming and Kafka, handling billions of daily music events. Worked with Data Science teams to deploy personalized playlist recommendation services into production. Mentored cross-functional squads on cloud-native best practices, contributing to Spotify’s global engineering guild.

Full Stack Engineer at Booking.com

October 1, 2021 - October 1, 2021

Developed cloud-native monitoring dashboards using Angular, .NET Core, and SQL Server. Led frontend modernization from AngularJS to Angular 11, achieving 25% higher accessibility scores. Championed database optimization projects in T-SQL, reducing query time by 40%. Built fraud detection dashboards integrating AI/ML APIs, reducing fraudulent transactions by 20%. Migrated services to AWS Lambda and Kubernetes, reducing hosting costs by 30%. Mentored 4 junior engineers and led code review sessions. Redesigned booking flows with UX researchers, improving checkout completion rates by 12%.

Lead Frontend Engineer at Klarna

February 1, 2018 - February 1, 2018

Directed development of real-time analytics dashboards with React, WebSockets, and D3.js. Introduced React Native for cross-platform apps, reducing mobile development costs by 30%. Oversaw a distributed frontend team across 3 countries, aligning delivery with compliance requirements. Implemented progressive web apps (PWAs), improving load times for mobile users by 50%. Established automated testing pipelines, increasing release confidence and reducing regression bugs. Co-authored frontend performance standards adopted company-wide.

Full Stack Developer at SAP

September 1, 2016 - September 1, 2016

Built enterprise-grade communication platforms with React and Ember, boosting user engagement by 30%. Created scalable Laravel microservices with JWT-based authentication, improving interoperability. Advocated TDD, raising automated test coverage from 20% to 70%. Contributed to ERP modernization by transitioning legacy PHP apps to microservices on Docker and Kubernetes. Implemented role-based access controls (RBAC) for enterprise customers, improving compliance. Designed reusable frontend component libraries, reducing duplication across teams.

Full Stack Developer at Revolut

February 1, 2014 - February 1, 2014

Developed secure online banking systems handling millions of daily transactions using Java Spring MVC and REST/SOAP APIs. Migrated monolithic services to SOA (Spring Boot + Apache CXF), cutting release cycles from quarterly to monthly. Built real-time fraud detection dashboards in D3.js, enhancing compliance reporting. Integrated multiple third-party financial APIs, ensuring SEPA and PSD2 compliance. Automated testing suites with JUnit and Selenium, reducing critical bugs in production by 35%. Created interactive loan calculators, increasing customer adoption by 18%.

Web Developer Intern at Trafi

December 1, 2011 - December 1, 2011

Supported senior engineers in building secure e-signature workflows for Java EE-based portals. Improved application reliability by 25% through bug fixes and UI test automation. Designed new onboarding flows, streamlining registration and reducing drop-off rates. Contributed to early adoption of agile processes within the engineering team.

Freelance Full Stack Engineer at Freelance (European clients)

December 31, 2012 - December 31, 2012

Delivered 10+ custom web applications for European clients covering e-commerce, booking, and SaaS platforms. Stack: PHP, MySQL, jQuery, WordPress.