I'm a senior software engineer with 10+ years building scalable backend systems, data infrastructure, and CI/CD pipelines for fintech, medtech, e-commerce, and SaaS companies. I specialize in transforming legacy applications into modern, cloud-native architectures and delivering production-ready solutions. WHAT I DO BEST Backend Development: PHP (Laravel, Symfony, Zend, PHP 8+, WordPress), Python (FastAPI, Flask), Node.js (NestJS, Express.js), RESTful APIs, microservices, event-driven systems, database optimization (MySQL, PostgreSQL, Redis, DynamoDB) Data Engineering: ETL/ELT pipelines with DBT, Snowflake, Apache Spark (Scala), data modeling and SQL optimization, real-time processing, workflow orchestration (Airflow, Dagster) DevOps and Cloud: AWS (Lambda, EC2, ECS, RDS, S3, SQS/SNS), Infrastructure as Code (Terraform, Ansible), containerization (Docker, Kubernetes), CI/CD (GitHub Actions, GitLab CI/CD, Jenkins, Bazel), monitoring (CloudWatch, Prometheus, Grafana) Database Engineering: MySQL and PostgreSQL (performance tuning, indexing, replication), NoSQL (DynamoDB, Redis), search engines (Solr, Elasticsearch), data warehousing (Snowflake) SERVICES I OFFER Backend API Development: Build secure, scalable REST APIs and microservices from scratch or enhance existing systems Legacy System Modernization: Refactor monolithic applications into maintainable, cloud-ready architectures DevOps and Infrastructure Automation: Set up CI/CD pipelines, containerize applications, automate deployments with Terraform Data Pipeline Engineering: Design and implement ETL/ELT workflows for analytics, reporting, and data integration Cloud Migration and Optimization: Migrate on-premise systems to AWS with cost optimization and scalability Technical Consulting: Architecture reviews, performance audits, and technical roadmap planning WHAT SETS ME APART Production-Ready Code: Every delivery includes clean, documented code, comprehensive testing, and deployment automation Full Lifecycle Ownership: From architecture design to production deployment and post-launch support DevOps Mindset: I build systems that are easy to deploy, monitor, and maintain Clear Communication: Regular updates, transparent timelines, and collaborative problem-solving Long-Term Thinking: Solutions built for maintainability, not quick fixes that create technical debt IDEAL PROJECTS Building backend APIs and microservices. Data pipeline development and warehouse integration. AWS infrastructure setup and optimization. CI/CD pipeline implementation. Legacy application modernization. Database design and optimization. Kubernetes deployment and orchestration. RECENT WORK Architected enterprise-grade CI/CD pipelines using GitHub Actions and Bazel, reducing deployment time by 40%. Built comprehensive data pipelines using DBT and Snowflake for fintech client. Refactored legacy e-commerce backend to Laravel, improving performance by 50%. Designed AWS infrastructure using Terraform for scalable cloud deployments. MY APPROACH I believe great engineering isn't just about writing code, it's about building systems that empower teams to move faster and ship with confidence. Whether you need a one-time API service or complete platform overhaul, I focus on delivering solutions that are robust, scalable, and easy for your team to evolve. Available for short-term projects and ongoing collaborations. If you're looking for a senior engineer who can architect, build, and deploy backend systems or data infrastructure with a DevOps-first mindset, let's discuss your project.

Hi, my name is Alex Cristescu and I am specialized in: Google Analytics 4 & GTM Server-Side Tracking Expert | Meta CAPI | Shopify | BigQuery Overview: Google Analytics 4 (GA4), Google Tag Manager (GTM), and server-side tracking specialist helping ecommerce brands and lead-gen businesses fix broken conversion tracking and scale campaigns with accurate, privacy-compliant data. Expert in Meta Pixel & Conversions API (CAPI), Shopify tracking, Google Ads & Microsoft Ads conversions, and robust first-party data solutions with Stape and Google Cloud Platform (GCP). Top Rated Plus freelancer with 13+ years in web analytics, tag management, and marketing data infrastructure. Core services: • GA4 & GTM setup, audits, and migration (events, ecommerce, custom dimensions/metrics) • Server-side tagging with Stape/GCP for faster sites, better data durability • Meta Pixel, Meta CAPI, Google Ads Enhanced Conversions, TikTok, Pinterest, Snapchat, Microsoft Ads • Shopify, WooCommerce, and custom ecommerce tracking • GDPR-compliant consent mode, first-party data, cross-domain and iframe tracking • BigQuery + Looker Studio dashboards for revenue, ROAS, funnel, and marketing attribution What you get: • Accurate GA4 conversion tracking across ecommerce and lead funnels • Reliable Meta CAPI & Google Ads data that survives browser restrictions • Clear reporting in Looker Studio and BigQuery to show true marketing performance If you need a Google Analytics, GTM, and server-side tracking expert to audit your setup, implement accurate tracking, or design a robust measurement stack, send your stack details and you’ll get a concrete action plan to fix and optimize your data flow.

Hello, I'm a professional top rated, 100% job success VBA developer. Do you find yourself performing repetitive tasks on Excel? Want to expedite report emission? Need automation solutions? Any task can be automated through Excel. Allow me to help you organize and automate your regular tasks into something that will make your business run more efficiently. I am currently work as a VBA Developer in a company. I have over 7 years of experience working with Excel and VBA, Tableau, and other Office programs. I can help you with all types of automation made in Excel (migrate data from/to Excel to/from Word, PowerPoint, PDF or Access, create tools with login interface, etc) Strengths and skills : · Advanced Excel formulas and data manipulation · VBA Scripting (Excel Macros, Excel VBA) · Creating Excel macros for complicated dynamic tasks · Developing dashboards in Excel · Automation, modifying and optimizing reports using Excel VBA · Creating and updating automated scripts for graphs, charts, and data tables · Collecting and connecting data across the databases and information sources · Troubleshooting and modifying VBA code · Utilize VBA script to connect and control tasks with other MS applications (PowerPoint, Outlook, Word, SQL, etc) I believe my capabilities are perfect for building any Excel related projects.

My diverse background has given me the ability to grow and learn in many ways others have not. I have gotten my “hands dirty” by dipping into numerous businesses and life experiences. Some of the industries I have worked in are; farm and agriculture, retail, e-commerce, student athletics, student government, and non-profit organizations, travel industry, mortgage banking, endurance sports, accounting & finance, and insurance. My experiences include and are not limited to; coaching, consulting, retail/logistics, e-commerce sales, business analysis/business intelligence, data collection & analysis, risk management, budgeting, project management, and investing. "Why do you title yourself as an Entrepreneur opposed to an Analyst?" - My answer is simple, not one title, skill, or experience defines me. I am not just an employee, but an asset. All data has quirks, each can be understood, some just take longer to understand than others. I will typically respond in less than a day.

17+ years in cloud and infrastructure. 332+ successful projects. Multiple active certifications. No recurring issues. No temporary fixes. Only engineered, permanent solutions. I don’t patch problems — I design systems where they don’t return. Multi-certified Cloud Architect & Infrastructure Specialist, recognized in Upwork’s top 1% (Expert-Vetted) through independent technical evaluation. ━━ CLOUD ARCHITECTURE & ENGINEERING ━━ AWS: EC2, S3, RDS, SES, IAM, Lambda, VPC, Route 53, CloudFront, ELB, CloudTrail, Auto Scaling Azure: App Services, Azure AD, Virtual Machines, AKS, NSG, Logic Apps, Azure Monitor, App Gateway GCP: GCE, GCS, Cloud SQL, Cloud Run, GKE, Cloud DNS, Vertex AI, BigQuery ✔ Multi-cloud architecture & hybrid environments ✔ Cost optimization & FinOps strategies ✔ Infrastructure as Code: Terraform, ARM, CloudFormation ✔ Cloud migrations: lift-and-shift, re-platform, re-architect ━━ CLOUD SECURITY & DEVSECOPS ━━ ✔ Zero-trust architecture & IAM hardening ✔ RBAC, MFA, PAM, least-privilege enforcement ✔ SSL/TLS (Let’s Encrypt, DigiCert, Sectigo, wildcard/SAN) ✔ Firewall design: iptables, UFW, Windows Firewall, AWS SG, Azure NSG ✔ CIS benchmarks, CVE remediation, vulnerability assessments ✔ SIEM integration, audit logging, compliance alignment (SOC 2, ISO 27001, HIPAA) ✔ Secrets management: HashiCorp Vault, AWS Secrets Manager ✔ Incident response & forensic analysis ━━ DEVOPS & AUTOMATION ━━ ✔ CI/CD: Azure DevOps, GitHub Actions, Jenkins, GitLab CI ✔ IaC: Terraform, ARM, CloudFormation, Ansible ✔ Containers: Docker, Kubernetes (AKS, GKE, EKS), Helm ✔ Deployment strategies: blue-green, canary, rolling, auto-rollback ✔ Monitoring: CloudWatch, Azure Monitor, Grafana, Prometheus, Nagios ━━ SERVER & SYSTEM ADMINISTRATION ━━ ✔ Windows Server (2008–2022): deployment, hardening, migration ✔ Linux (Ubuntu, CentOS, RHEL, Debian): administration & performance tuning ✔ Active Directory, GPO, DNS, DHCP, RDS, Hyper-V, VMware ✔ Web servers: IIS, Apache, Nginx (performance & scaling) ✔ Control panels: cPanel, WHM, Plesk, Virtualmin ✔ VPS & dedicated hosting across major providers ━━ EMAIL DELIVERABILITY & DNS ━━ ✔ SPF, DKIM, DMARC — audit, enforcement (none → reject) ✔ DNS management: Cloudflare, Route 53, GoDaddy, Namecheap ✔ AWS SES: reputation repair, warm-up, deliverability optimization ✔ Google Workspace & Microsoft 365 migrations ✔ SMTP systems: Postfix, Exim, SendGrid, Mailgun ✔ Blacklist removal, spam score improvement, inbox placement ━━ DATABASE ADMINISTRATION ━━ ✔ MS SQL Server, MySQL, PostgreSQL, MongoDB, Redis ✔ Managed DBs: Azure SQL, AWS RDS, Cloud SQL ✔ Performance tuning, indexing, replication, backups, DR ━━ AI & ML INFRASTRUCTURE ━━ ✔ AWS SageMaker, Azure ML, GCP Vertex AI ✔ GPU-based ML infrastructure & scalable pipelines ✔ MLOps & model serving ✔ Vector DBs: Pinecone, Weaviate, ChromaDB ━━ NETWORKING ━━ ✔ VPN: OpenVPN, WireGuard, AWS/Azure VPN ✔ VLANs, subnetting, routing, NAT ✔ Load balancing, CDN, reverse proxy architecture ✔ Secure network design & performance optimization ━━ CERTIFICATIONS (UPWORK-VERIFIED) ━━ ✔ AWS Solutions Architect (Professional & Associate) ✔ Microsoft Azure Solutions Architect Expert ✔ Azure Administrator Associate ✔ Google Professional Cloud Architect ✔ Microsoft Certified Professional ━━ WHY CLIENTS CHOOSE ME ━━ ✔ Expert-Vetted (Top 1% on Upwork — independently assessed) ✔ 0–4 hour response time ✔ Complete documentation with every project ✔ Security-first, production-grade architecture ✔ No shortcuts. No recurring issues. 🔥 CALL TO ACTION Have a complex infrastructure problem? Send details — you’ll get a clear, actionable plan within 4 hours.

Although new to Upwork, I am an experienced Access and Excel VBA Programmer, as well as a seasoned database administrator/designer. I have worked on Access and Excel projects for over twenty years. I have worked on a variety of projects. Some simple in design with just a few database tables, to large complex databases with many database tables. Over time, I have developed several Access Class Objects that greatly simply the implementation of complex routines. These class objects are available for use in your project(s) with no additional fee or royalty. The objects are described in the following paragraphs. DRAG AND DROP - this is a capability that is not native to Access. It allows the user to grab a screen control and then drag it to another location on the form. For example, rearranging the entries on a schedule, like changing a clients appointment date or time. SEARCHING A DATABASE TABLE - This object makes it easy to implement the task of searching for an entry in a database table. To the user it appears as if they are using a standard dropdown control, but with the ability to type in search criteria. (For example, searching for customers, vendors, products, accounts, etc.) I can usually make a field on a form searchable in less than an hour. This object used on key controls saves time and frustration for database users. Rather than scroll through a long list, they can type in the criteria to limit the list. SECURE DATABASE ACCESS - This object model allows you to secure user access to the database. beyond the native capabilities of Windows/Access. This can be implemented at both the form level and at the field/control level. LOGGING/AUDIT TRAIL - This object model provides a log/audit trail of database access and changes with minimal coding. You can easily see who changed what and when they did it. ERROR AND ACKNOWLEDGEMENT MESSAGING - communicating effectively with the user has always been problematic with Access. To address this, I created this object to standardize and simply communication with the user. The object is used to issue acknowledgement messages, like a record has successfully been added. Error messages of differing severity, warning, error, or sever. The messages are display beneath the field/control in error, and the error control's outline is highlighted in red. Making it easy for the user to see what is wrong. Lastly, years ago, I was in charge of database administration for the Walt Disney Company. All database design for the corporation was performed by my group.

I’m a passionate Full-Stack and Mobile App Developer with 15+ years of experience building high-performance web, mobile, and AI-driven applications that help businesses launch, scale, and innovate. Whether you need a sleek mobile app, a robust enterprise platform, or cutting-edge AI solutions, I bring the expertise to bring your vision to life. 🤝What I Do Best🤝 📌Mobile App Development: iOS (Swift, Objective-C), Android (Kotlin, Java), Firebase 📌Full-Stack Development: .NET Core, Node.js, React, Angular, Vue.js, Python 📌AI & ML: OpenAI, TensorFlow, NLP, AI-Powered Automation 📌Cloud & DevOps: AWS, Azure, Kubernetes, Docker, CI/CD Pipelines 📌Databases & Integrations: SQL Server, MongoDB, PostgreSQL, Stripe, HubSpot 📌3rd-Party API Integrations: Payments, Messaging, Social APIs 🏭Industries I’ve Worked With:🏭 ➡️FinTech & Banking – Secure transactions, fraud detection, and payment gateways ➡️Healthcare & Telemedicine – HIPAA-compliant platforms for secure patient data ➡️E-commerce & Marketplaces – Scalable shopping experiences with AI-powered recommendations ➡️Fitness & Wellness – AI-driven tracking, analytics, and personalized programs ➡️Social Networking – Real-time, high-engagement platforms with seamless user interactions 🎯Why Work With Me?🎯 ✔️ Scalable & High-Performance Development – From MVPs to enterprise solutions ✔️ AI-Powered Innovation – Integrating AI/ML to supercharge your business ✔️ Agile & Fast Execution – Rapid prototyping, iterative development, and smooth workflows ✔️ End-to-End Support – From planning to post-launch maintenance ✔️ Transparent & Communicative – Clear updates, collaborative approach, and on-time delivery 🚀 Let’s build something amazing together! If you're looking for a top-tier developer who can bring your ideas to life with scalability, performance, and innovation, let’s connect. 🎯

I have 25 years of IT experience. My strengths are: 1. I am technically Strong. Has strong hands on skills. 2. I have strong designing skills. 3. I have experience Managing Projects and skills in many Project Management Tools. My Skills: 1. All PM tools - MS Project, ChangePoint etc. 2. Hands On experience on Excel VBA and Excel Add-In for all kinds of requirements. 3. Hands on experience in HTML5, Javascript, Jquery, Bootstrap 4. PHP Laravel, MySQL, Amazon RDS, Azure SQL 5. Google Workspace Add-Ons 6. Google App Script, Google Data Studio, Corezoid 7. Hands on experience on Java, Android UI development. 8.Facebook API, Amazon MWS API, twilio API, ringcentral API, Signalwire API 9. CRM: Zendesk and Hubspot, 10. Payments: Stripe Payments.

Data Scientist & Statistician of experience in R, Python, SPSS,Excel،Power BI and SQL. I specialize in machine learning, predictive modeling, biostatistics, clustering, classification, and data visualization. R Packages: tidyverse, tidymodels, dplyr, ggplot2, caret, randomForest, glmnet, xgboost, nnet, lme4, forecast, data.table, readr, stringr, Shiny, Quarto, R Markdown and much more Python Packages: pandas, numpy, scikit-learn, statsmodels, matplotlib, seaborn, plotly, TensorFlow, Keras, PyTorch, XGBoost, LightGBM, CatBoost. Other Tools: SPSS, SAS, Minitab,Power BI, PASS, Microsoft Excel/Office, SQL, Power BI etc... I deliver clean, reproducible, and decision-ready analytics — from statistical modeling and survey analysis to machine learning pipelines and dashboards.

I architect and build production-grade data platforms for companies that have outgrown spreadsheets and fragile BI. I specialize in designing full-stack Snowflake + dbt + Airflow systems that power executive and investor-level reporting. For the past 6+ years, I’ve owned end-to-end data architecture — from ingestion and warehouse design to modeling, orchestration, and executive reporting. I don’t just write queries — I build the full system. Recent platform builds • KnowV8 (US-based analytics company) – Sole architect and engineer of a fully automated Snowflake + dbt + Airflow stack powering daily production reporting. Designed ingestion workflows, dimensional models, and reporting structures used for executive decision-making. • Optium Capital (US PE-backed firm) – Designed and built a Snowflake-based analytics platform integrating multiple data sources, enabling governed reporting and replacing spreadsheet-driven processes. • RTL (Enterprise Media Company) – Integrated a new large-scale data source into an existing Snowflake + dbt + Airflow ecosystem. Worked with datasets exceeding 100M–1B+ rows, ensuring scalability and data integrity. ⸻ What I help clients with • Architecting scalable Snowflake-based data warehouses • Designing clean, maintainable dbt transformation layers • Building reliable Airflow pipelines for production workflows • Replacing Excel-based reporting with structured BI • Creating consistent, auditable numbers for leadership teams • Connecting APIs and external data sources into modern data stacks ⸻ Core stack Python, SQL, Snowflake, dbt, Airflow, AWS/S3, Tableau, Power BI, Azure ⸻ If you need someone who can both design the architecture and implement it end-to-end — I’m that person.