Ali is available for hire

Ali Karademir

Verified Expert in Engineering

Back-end Engineer and Developer

Surrey, BC, Canada

Toptal member since January 20, 2026

Expertise

API SQL Java REST API Spring Microservices Development JUnit Docker Git Postman Kubernetes

Bio

Ali is a lead, back-end engineer, and architect with 25+ years of experience building and scaling global enterprise platforms for Fortune 500 companies, including Mastercard, Lululemon, Palo Alto Networks, Best Buy, Western Union, and HSBC. He is an expert in API Gateways using Apigee, Java/Spring Boot, Kafka, Kubernetes, AWS, GCP, OAuth2.0, and distributed systems. A proven tech leader, Ali drives architecture, platform modernization, and cross-functional alignment in engineering.

Portfolio

Lululemon Athletica

Amazon Web Services (AWS), Apache Kafka, Apigee Edge, Spring 6, Spring Boot...

Palo Alto Networks

Google Kubernetes Engine (GKE), Helm, Docker, GitLab CI/CD, Apache Kafka...

Western Union

Spring Boot, Java 8, Okta, Spring Security, OAuth 2, OpenID Connect (OIDC)...

Experience

Java - 20 years
Object-oriented Programming (OOP) - 20 years
SQL - 20 years
Design Patterns - 15 years
Spring Boot - 10 years
Microservices - 10 years
API Management - 4 years
Spring 6 - 4 years

Preferred Environment

Apache Kafka, Spring Boot, Apigee Edge, Google Kubernetes Engine (GKE), Amazon Web Services (AWS), Java 8, SQL, Design Patterns, Cloud Native Applications, Spring 6

The most amazing...

...project I've led is Lululemon’s OMS API migration from Amazon API Gateway to Apigee, owning architecture, design, onboarding, & delivery across platform teams.

Work Experience

Technical Architect | Development Lead

2023 - 2025

Lululemon Athletica

Led the migration of 30+ order management system (OMS) service APIs from Amazon API Gateway to Apigee Edge, achieving 100% platform adoption across global commerce teams.
Reduced API latency by 25-35% and improved request throughput by over 40% through optimized gateway routing, caching, and standardized policies.
Increased API availability to 99.95% by modernizing Kafka-based resiliency, exception handling, and retry patterns across event-driven microservices.
Designed and enforced shared core libraries used by 10+ microservices teams, reducing duplicated code by around 30% and accelerating feature delivery.
Strengthened API security posture by implementing OAuth 2.0 and OpenID Connect (OIDC), reducing security-related incidents and audit findings by around 50%.
Improved the mean time to recovery (MTTR) by around 40% through proactive observability using Splunk and Datadog dashboards, alerts, and service-level indicators.
Enabled seamless onboarding of distributed teams across North America and EMEA, cutting average service onboarding time from weeks to under five days.
Led sprint planning, estimation, and technical delivery for multiple parallel streams, consistently delivering releases on schedule with a less than 2% rollback rate.
Conducted architectural assessments and POCs that de-risked platform changes, preventing costly rework and ensuring smooth enterprise-scale migrations.
Provided post-release hyper-care and root-cause analysis for production issues, sustaining stable operations during peak retail traffic periods.

Technologies: Amazon Web Services (AWS), Apache Kafka, Apigee Edge, Spring 6, Spring Boot, Microservices, Kubernetes, Datadog, Splunk, Java 8, Docker, Test Containers, APIs, API Management, OAuth 2, Application Security, Java, Threat Modeling, API Gateways

Senior Staff Engineer

2022 - 2023

Palo Alto Networks

Designed and implemented FedRAMP-compliant security enhancements across SaaS Security Inline and SaaS Security API platforms, enabling deployment into regulated US government environments.
Introduced mutual TLS (mTLS) for Postgres database communication, reducing unauthorized access risk and improving data-in-transit security to 100% encrypted coverage.
Remediated critical vulnerabilities in 3rd-party libraries across multiple microservices, reducing reported security findings by over 95% during internal and external audits.
Improved service reliability to over 99.95% uptime by strengthening deployment stability, configuration management, and runtime hardening in Kubernetes-based environments.
Developed reusable reactive libraries for Kafka producers and consumers, increasing event-processing throughput and reducing message handling latency by 20-30% at least.
Accelerated feature development across multiple teams by standardizing reactive patterns, cutting duplicate Kafka logic and reducing onboarding time for new services.
Supported Kubernetes and Helm-based deployments across environments, reducing deployment failures and rollbacks by 30-35% through improved templates and configuration consistency.
Enhanced CI/CD pipelines to support security and compliance requirements, decreasing build and release cycle times by around 25% while maintaining strict quality gates.
Diagnosed and resolved complex production and pre-production issues across distributed systems, reducing the MTTR by 30-40%.
Collaborated with cross-functional security, infrastructure, and product teams to deliver compliant features on schedule without disrupting active customer deployments.

Technologies: Google Kubernetes Engine (GKE), Helm, Docker, GitLab CI/CD, Apache Kafka, Spring 6, Spring Boot, Java 8, Apache Maven, Gradle, MongoDB, PostgreSQL, Git, Jenkins, Bitbucket, Jira, Java, API Gateways

Senior Java & Microservices Consultant

2021 - 2022

Western Union

Designed and implemented a Spring Boot-based identity management POC using OAuth 2.0, OIDC, social login, and Okta, accelerating developer onboarding by at least 50%.
Integrated Okta APIs into Spring Security workflows, enabling secure token-based authentication flows with over 99.9% availability under enterprise benchmarks.
Developed an end-to-end test automation suite using Karate, increasing API test coverage to over 90% and reducing regression defects by around 75%.
Reduced manual QA effort by 80% through automated security and integration testing of identity services.
Provided technical guidance on OAuth 2.0 and OIDC concepts, shortening ramp-up time for new engineers and improving team delivery velocity.

Technologies: Spring Boot, Java 8, Okta, Spring Security, OAuth 2, OpenID Connect (OIDC), Social Login, Karate API Testing, Java

Lead Java Developer

2019 - 2021

Best Buy Canada

Led the design and development of the Sales Hub event-driven integration platform, enabling seamless integration between POS, eCommerce, finance, inventory, and data warehouse systems.
Improved order and event processing reliability to over 99.99% uptime by applying microservices resiliency patterns such as circuit breakers, retries, and asynchronous messaging across RabbitMQ-based workflows.
Increased integration throughput by 30-40% by optimizing asynchronous message flows and leveraging Spring Cloud Stream with consumer-driven contract testing.
Reduced end-to-end order processing latency by 30% by refactoring synchronous integrations into event-driven microservices.
Standardized service contracts using consumer-driven contract tests, reducing cross-team integration defects by 50% and accelerating release cycles.
Delivered complex platform features while leading architectural discussions, improving maintainability and scalability as transaction volumes scaled during peak retail periods.
Supported CI/CD pipelines and containerized deployments on OpenShift, resulting in a huge reduction of deployment-related incidents and rollbacks.

Technologies: Spring Boot, Java 8, Spring Cloud, Microservices, RabbitMQ, Oracle RDBMS, SPOC, Git, Bitbucket, Jira, OpenShift, Docker, Test Automation Frameworks, NoSQL, MongoDB, REST APIs, OpenAPI, CI/CD Pipelines, XSD, Object Orientented Design, Spring Data JPA, Spring REST, System Design, Java

Senior Full-stack Developer

2018 - 2019

Broadridge Financial Solutions

Designed and developed core features of the INFORM investment account onboarding platform, supporting multiple account types and improving end-to-end onboarding completion rates.
Implemented Spring Boot-based REST APIs and business process management-driven workflows (Flowable), reducing manual processing steps and cutting the average onboarding cycle time by 85%.
Built secure, role-based business process lifecycle management, enabling huge increases in platform availability for internal operations teams.
Developed a modern Vue front end with reusable components, improving UI responsiveness and reducing user-reported issues by 30%.
Increased test reliability and release confidence by implementing unit and end-to-end automation, achieving over 80% test coverage and reducing regression defects by at least 35%.

Technologies: Java 8, Spring Boot, Vue, ECMAScript (ES6), PostgreSQL, Spring Data JPA, Spring REST, Flowable, Nightwatch.js, Axios, Bootstrap 4, Jest, Java

Senior Java/Jakarta EE Developer

2012 - 2018

Best Buy Canada

Architected and developed messaging-based microservices to modernize a legacy monolithic order processing system, improving system scalability and enabling 99.99% order availability.
Designed and implemented major OMS capabilities, including PayPal integration, ship-from-store, delivery promise, and marketplace, increasing checkout success rates by 20-30%.
Reduced order processing latency by 50% by decoupling synchronous workflows into asynchronous, event-driven services using RabbitMQ.
Improved peak-traffic resiliency by 40% through circuit breakers, retries, and message-driven fault isolation patterns.
Developed SoapUI mock services for 3rd-party vendors, reducing external dependency blockers and accelerating integration testing cycles by 80%.
Acted as a full-stack contributor across back-end, middleware, and front-end layers, increasing delivery velocity and reducing cross-team dependencies.
Enhanced system observability and diagnostics, significantly reducing the MTTR during production incidents.
Supported high-volume retail events such as holiday sales by tuning message throughput and database access patterns, sustaining stable operations of under 2-3x traffic spikes.
Improved code quality and release stability through unit and integration testing, lowering post-release defects by 40%.
Collaborated with cross-functional business and technology teams to translate complex fulfillment requirements into scalable, production-ready solutions.

Technologies: Spring Boot, Java SE (Core Java), Spring Cloud, Spring REST, RabbitMQ, OpenShift, Cloud Native Applications, Spring Data JPA, MyBatis, Oracle PL/SQL, AngularJS, ECMAScript (ES6), MongoDB, Git, Apache Maven, Jenkins, Spock Framework, Mockito, SoapUI, UML, Team Leadership, API Design, Java

Technical Lead | Senior Developer Analyst

2007 - 2012

TELUS

Led solution architecture and development for the software-defined service enablement order processing platform, supporting thousands of daily transactions for small- and medium-sized business customers with 99.9% service availability.
Designed and implemented an asynchronous error-handling and reprocessing framework, reducing manual intervention and lowering failed transaction recovery time by 70%.
Automated retry and exception workflows for distributed service calls, improving overall order completion rates by 30-40%.
Delivered TELUS SOA services and batch processing jobs for consumer and business order platforms, sustaining stable operations during 2x peak load periods.
Reduced the MTTR greatly by improving logging, diagnostics, and structured error analysis across service layers.
Led design reviews, sprint planning, estimation, and technical delivery for cross-functional teams, consistently meeting release timelines with minimal post-release defects of under 1%.
Mentored and coached developers through code reviews and architectural guidance, improving code quality and reducing rework by considerably huge quantities.

Technologies: Solution Architecting, Team Leadership, API Design, Java SE (Core Java), Spring, Batch File Processing, Control-M, WebLogic, Front-end Development, JavaScript, JUnit, Management Systems, Java EE (Jakarta EE), Java

Experience

OMS API Gateway Modernization for Lululemon

Modernized the API Gateway platform for Lululemon.

I created the solution architecture, including API gateway platform selection, API security implementation using OAuth2, selection of app, product, and proxy deployment approaches, direction for development activities, and support and coordination. I also led and supported the onboarding of application teams to the new platform, supported, maintained, and enhanced the platform for peak seasons API traffic, and effectively and efficiently resolved production issues.

Event-driven Microservices-based Integration Platform Sales Hub for Best Buy Canada

Sales Hub is a platform for integrating Best Buy's newly acquired point-of-sale system with its existing web order processing system and various corporate systems, such as accounting, finance, data warehouse, and inventory management systems.

I served as the most senior developer proposing solutions to new problems using industry-accepted best practices and design patterns to ensure a flexible, maintainable, and scalable integration platform. I also led design discussions, proposed designs, and brainstormed with the team on potential improvements. Additionally, I developed complex new sets of features in an Agile environment using Scrum with 2-week sprints and a cross-functional team.

Education

1993 - 1998

Bachelor's Degree in Computer Science

Bilkent University - Ankara, Turkiye

Skills

Libraries/APIs

REST APIs, Spring REST, MyBatis, OpenAPI, Vue, Nightwatch.js

Tools

Apache Maven, Git, RabbitMQ, SoapUI, Postman, Google Kubernetes Engine (GKE), Splunk, Helm, GitLab CI/CD, Gradle, Jenkins, Bitbucket, Jira, Karate API Testing, Control-M

Languages

Java 8, SQL, Java SE (Core Java), Java, XSD, UML, JavaScript, ECMAScript (ES6)

Frameworks

JUnit, OAuth 2, AngularJS, Spock Framework, Mockito, Spring, Spring Boot, Spring 6, Spring Security, Jest

Paradigms

Object-oriented Programming (OOP), Microservices, Design Patterns, Test Automation

Platforms

Kubernetes, Docker, OpenShift, Java EE (Jakarta EE), Apache Kafka, Amazon Web Services (AWS)

Storage

Oracle RDBMS, Spring Data JPA, Datadog, PostgreSQL, NoSQL, MongoDB, Oracle PL/SQL

Other

Software Engineering, APIs, Object Orientented Design, API Design, Cloud Native Applications, Test Containers, API Management, Spring Cloud, SPOC, Test Automation Frameworks, System Design, Team Leadership, Solution Architecting, Batch File Processing, Front-end Development, Management Systems, API Gateways, Solution Design, Apigee Edge, Computer Science, Software Systems Design, Programming Languages, Application Security, Okta, OpenID Connect (OIDC), Social Login, CI/CD Pipelines, Flowable, Axios, Bootstrap 4, WebLogic, Disaster Recovery Plans (DRP), Service Meshes, Threat Modeling, RESTful Services

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