Fayaz Deen Open to new roles

Senior Technical Lead at NULogicSantiago, Chile

Fayaz Deen

Java · Spring Boot · Microservices · Distributed Systems

I build and lead the Java backends behind enterprise commerce, search, payments and data platforms, for global brands including Sephora, Macy’s, Express, PayPal, Wild Fork and UPPAbaby.

Open to Lead, Staff and Senior Backend Engineer roles
Open to relocating anywhere · remote, hybrid or on-site

Get in touch LinkedIn ↗ GitHub ↗
years building in Java
10+
global brands served
6
brands on headless commerce
4
Claude Academy badges
15
  • NULogic
  • Sephora
  • Macy’s
  • Express
  • PayPal
  • Wild Fork
  • UPPAbaby
  • Crown SolutionsIndia Pvt Ltd

Profile

Leading through architecture and example

Fayaz Deen

Mohamed Fayaz Deen H

Senior Technical Lead · NULogic

Senior Technical Lead with 10+ years building enterprise commerce, search, payments and data platforms in Java. Grew from Junior Developer (2016) to Senior Technical Lead (2025), and now lead parallel client programs for NULogic, on-site in Santiago, Chile.

Deep in Java, Spring Boot, microservices, REST APIs and distributed systems: event-driven design on Kafka, Redis and Cassandra, with cloud work across AWS, GCP and Azure. Specialist in Commercetools headless commerce.

I own design decisions, work directly with enterprise client stakeholders, mentor engineers and set the bar for designs, code reviews and tests. I use Claude Code and AI-assisted workflows every day to speed up delivery, with every change reviewed by a human.

  • search · Express

    Google Retail Search, built from scratch

    End-to-end search for web and mobile, with multi-level faceting, ranking tuning, Elasticsearch autocomplete and SEO product feeds.

  • pipeline · Sephora

    Personalization at scale

    Architected the Azure Batch engine that renders personalized, eligibility-driven email layouts for millions of customer records.

  • events · Sephora

    Event-driven data sync

    Kafka as the message queue for Cosmos DB and ruleset updates, keeping data and business rules consistent across services.

  • commerce · 4 brands

    Headless commerce

    Commercetools catalog, pricing, discount, cart, checkout and inventory services for Sephora, Express, Wild Fork and UPPAbaby.

  • payments · PayPal

    Payments-grade reliability

    Hardened authentication and authorization with circuit breakers, idempotency, multi-data-center Redis session clustering and PCI-DSS compliance.

  • leadership · 2016 → 2025

    Engineering leadership

    Progressed from Junior Developer (2016) to Senior Technical Lead (2025); served as Solution Architect on Collectivus while leading Sephora and UPPAbaby delivery in parallel.

Career trace

Ten years, one trace

Every role is a span on a single trace, from July 2016 to now. Select a span to read its events.

root · career

span · current

Senior Technical Lead

NULogic

start Apr 2025end presentlocation Santiago, Chile (On-site)

  • Lead backend and commerce engineering across parallel enterprise programs (Sephora, UPPAbaby, Collectivus), owning architecture, design decisions, implementation strategy and code quality.
  • Shape service boundaries, data models and integration patterns for headless commerce, search, data pipelines and customer-engagement systems built on Spring Boot microservices.
  • Work directly with enterprise client stakeholders to turn business goals into requirements and delivery roadmaps.
  • Own cloud deployments, monitoring and production readiness for high-availability services.
  • Introduced Claude Code and AI-assisted workflows for prototyping, test generation, refactoring and documentation, with every change verified through code review.

span

Technical Lead

NULogic

start Aug 2022end Apr 2025location Chennai, India (Remote)

  • Led backend engineering for NULogic’s enterprise commerce clients Wild Fork, Express and Sephora.
  • Delivered Google Retail Search from scratch for Express web and mobile, plus Commercetools catalog, pricing, discount, cart and checkout services across three brands.
  • Drove microservices adoption with Spring Boot and RESTful APIs; supported AWS and Azure deployments, CI/CD pipelines and monitoring.
  • Mentored engineers, ran design and code reviews, and set the standard for low-level designs and unit tests.

span

Senior Software Engineer II

Altimetrik (client: PayPal)

start Aug 2021end Jul 2022location Chennai, India (Remote)

  • Built resilient Java microservices for PayPal’s core authentication and authorization platform, with circuit breakers, idempotency and secure token propagation.
  • Designed Redis session clustering across multiple data centers and Cassandra data models for high-throughput token storage; kept modules PCI-DSS compliant.

span

Software Engineer

Crown Solutions India Pvt Ltd (client: Macy’s) · Business Analyst designation

start Oct 2020end Jul 2021location Chennai, India (On-site)

  • Built guest checkout, secure password reset and post-purchase order and address management for macys.com in Java and Spring.
  • Turned business requirements into technical specs and REST APIs, and partnered with QA on functional testing.

span

Engineer

Hifi Technology

start Nov 2018end Sep 2020location Chennai, India (On-site)

  • Built the REST service layer and Hibernate persistence for E-Com Operator Management, a merchant admin platform for insurance plans and health claims; set up its cloud infrastructure from scratch.

span · first

Software Engineer

IVTL Infoview Technologies · Junior Developer to Full Stack Developer

start Jul 2016end Nov 2018location Chennai, India (On-site)

  • Converted a Delphi desktop application into a web application (2 modules solo, 3 with the team), then delivered the HUE ERP approval-flow module and led a team of 4 on its maintenance.

Selected platforms

Commerce, search, payments, data

  • data pipelines
  • event streaming
  • commerce
  • rules

Sephora

NULogicTechnical LeadFeb 2024 – Presentteam of 3

Omnichannel beauty commerce: a Commercetools-powered storefront and a personalized customer-engagement system for large-scale email campaigns.

email personalization pipeline

  1. Contentfullayouts
  2. Droolseligibility rules
  3. Azure Batchparallel jobs
  4. CSVper segment
  5. Epsilonemail send

event sync

  1. Servicesproducers
  2. Kafkamessage queue
  3. Cosmos DBdata + rulesets

Data pipelines & event streaming

  • Architected Azure Batch pipelines for CSV generation and personalized email content across millions of customer records, with independent job startup and robust error handling.
  • Used Kafka as the message queue for Cosmos DB and ruleset updates, keeping data and business rules in sync across services.
  • Led a high-performance email generation system with personalized layouts; built Epsilon templates with AI-driven subject-line optimization.
  • Built a Contentful-based content engine that renders layouts by customer eligibility and segment.
  • Raised throughput by tuning multi-threaded execution with the Java Executor framework, and optimized MySQL design for large-scale data operations.

Commercetools & digital commerce

  • Led Commercetools integration for catalog, pricing and inventory sync; designed REST APIs for products, categories and variants.
  • Built real-time product sync pipelines between Commercetools and backend systems; search and filtering with Product Projections and Query APIs.
  • Managed cart, checkout and order workflows and integrated third-party services.

Technical leadership

  • Implemented a Drools rule engine for complex business rules and customer targeting; built shared internal libraries reused across microservices.
  • Supported DevOps through Argo CD pipelines and configuration deployments; wrote LLDs, analysis documents and unit tests, and mentored the team.

Java · Spring Boot · Hibernate · Microservices · Kafka · Azure Batch · Azure Cosmos DB · Commercetools · Drools · Contentful · Epsilon · MySQL · Argo CD

  • search
  • commerce
  • payments

Express

NULogicSenior Software EngineerJan 2023 – Jan 2024team of 12

Headless omnichannel commerce for web and mobile with multi-gateway payments, dynamic promotions and SEO-optimized product feeds.

  • Implemented Google Retail Search from scratch for desktop and mobile, with multi-level faceted navigation and product feeds for indexing and SEO.
  • Integrated Elasticsearch for fast search and autocomplete, and tuned ranking logic.
  • Commercetools discounts, Subscriptions and API Extensions; Stripe, PayPal and Adyen payments; Redis caching to cut response times and database load.

Java · Spring Boot · Hibernate · Commercetools · Google Retail Search · Elasticsearch · Redis · MySQL · AWS (S3, Lambda, SQS, SNS, CloudWatch) · Stripe · PayPal · Adyen

  • auth
  • payments

PayPal

AltimetrikSenior Software Engineer IIAug 2021 – Jul 2022team of 30

Core authentication and authorization modules of one of the world’s largest online payment systems.

  • Circuit breakers and idempotency for critical authorization operations.
  • Redis session clustering across multiple data centers; Cassandra models for token storage; PCI-DSS.

Java · J2EE · Spring · Hibernate · Microservices · Redis · Cassandra · REST APIs · JUnit

  • commerce

UPPAbaby

NULogicSenior Full Stack DeveloperJul 2026 – Oct 2026team of 8

Direct-to-consumer commerce for a global maker of premium strollers, car seats and nursery products.

  • Commercetools catalog, variants and pricing across regional storefronts.
  • Modeled product–accessory compatibility so shoppers see only the parts that fit.

Java · Spring Boot · Microservices · Commercetools · REST APIs · MySQL · CI/CD

  • commerce
  • auth
  • payments

Wild Fork

NULogicSenior Software EngineerAug 2022 – Jan 2023team of 10

Direct-to-consumer premium meat and seafood (MeatMe), farm to fork, with Commercetools powering catalog, shopping and checkout on web and mobile.

  • REST APIs on Commercetools Product Projections; product-type schemas for cut, weight, origin and freshness, with real-time inventory sync.
  • Secure login with JWT access and refresh tokens, cross-device sessions and multi-factor authentication.
  • Dynamic checkout with real-time shipping rates and delivery-date estimates; payments with secure tokenization and PCI-compliant data handling.

Java · J2EE · Spring · Hibernate · Commercetools · REST APIs · JWT · MySQL

  • architecture
  • event-driven

Collectivus

NULogicSolution ArchitectJun 2026 – Aug 2026team of 10

Platform engineering program delivered through NULogic.

  • Owned architecture and design decisions as Solution Architect.
  • Spring Boot microservices, data models and event-driven workflows.

Java · Spring Boot · Microservices · REST APIs · Event-Driven Architecture · Cloud · CI/CD

  • checkout
  • accounts

Macy’s

Crown Solutions IndiaSoftware EngineerOct 2020 – Jul 2021team of 2

Checkout, accounts and orders for macys.com.

  • Guest checkout with session-based cart persistence and address validation.
  • Secure password reset with single-use expiring tokens; USPS address validation and split shipments.

Java · J2EE · Spring · JDBC · Web Services · REST APIs · MySQL

Earlier

E-Com Operator Management

Hifi TechnologyJava DeveloperNov 2018 – Sep 2020

Merchant admin platform for customer plans, insurance and medical-coverage membership and health claims. Built the REST service layer bottom-up and Hibernate persistence (Service and DAO patterns) on Spring MVC and Oracle; set up the cloud infrastructure from scratch.

HUE (High Usability Environment) and CJK / CSR

IVTL Infoview TechnologiesFull Stack / Junior DeveloperJul 2016 – Nov 2018

Delivered the HUE ERP approval-flow module end to end and led a team of 4 on its maintenance; built 2 CJK / CSR modules independently and 3 with the team while converting a Delphi desktop application into a web application.

Stack

What I work with

Backend Engineering
  • Java 8+
  • Spring Boot
  • Spring MVC
  • Hibernate
  • J2EE
  • Microservices
  • REST APIs
  • Multithreading (Executor framework)
  • Batch Processing
  • Performance Optimization
Distributed Systems
  • Kafka
  • RabbitMQ
  • Event-Driven Architecture
  • Circuit Breakers
  • Idempotency
  • Distributed Caching
  • Multi-Data-Center Session Clustering
  • API Gateway Integration
Architecture & Leadership
  • Solution Architecture
  • Low-Level Design
  • Technical Strategy
  • Enterprise Client Engagement
  • Mentoring
  • Design & Code Reviews
  • Agile Delivery
Data & Caching
  • MySQL
  • Oracle
  • Cassandra
  • Azure Cosmos DB
  • Redis
  • Elasticsearch
E-Commerce & Retail
  • Commercetools: Product, Cart and Order APIs
  • Product Projections
  • Discounts
  • Custom Types
  • API Extensions
  • Subscriptions
  • Catalog & PIM
  • Pricing & Promotions
  • Checkout
  • Payments: Stripe, PayPal, Adyen
  • Order Management
  • Inventory
  • Customer Segmentation
Cloud & DevOps
  • AWS: S3, Lambda, SQS, SNS, CloudWatch
  • GCP: Pub/Sub, Cloud Storage, Google Retail Search
  • Azure: Batch, Cosmos DB
  • CI/CD
  • Argo CD
  • Infrastructure-as-Code
Search & Discovery
  • Google Retail Search
  • Elasticsearch
  • Faceted Navigation
  • Autocomplete
  • Relevance & Ranking Tuning
  • Product Feeds
  • SEO
Security
  • JWT access & refresh tokens
  • Multi-Factor Authentication
  • Secure Token Propagation
  • Payment Tokenization
  • PCI-DSS
Observability
  • Prometheus
  • Grafana
  • ELK
  • Sleuth
  • Cloud Trace
  • Monitoring & Alerting
Rules, Content & Marketing
  • Drools
  • Contentful
  • Epsilon
AI-Assisted Engineering
  • Claude Code
  • Claude AI
  • Agentic Workflows
  • Multi-Agent Orchestration
  • Prompt Engineering
  • AI-Assisted Code Review, Testing & Documentation
Testing & Tools
  • JUnit
  • Integration & Regression Testing
  • Postman
  • GitHub
  • Maven
  • IntelliJ IDEA
  • Eclipse
  • Tomcat
  • React (API integration)

Credentials

Certifications

Claude Academy · Anthropic

15 course badges · issued Oct 2026 · each one verifiable

Contact

Let’s build the next platform

Email is the fastest way to reach me.

LinkedIn ↗ GitHub ↗
Roles
Lead · Staff · Senior Backend Engineer
Relocation
Open to any location · remote, hybrid or on-site
Based currently in
Santiago, Chile