Sebastian R. Estenssoro

Designed and implemented secure, production-grade AWS infrastructure for containerized workloads, including CodeBuild runners, ECR repository policies, VPC integrations, and IAM least-privilege roles used across multi-account environments. Built and refactored Terraform modules to standardize infrastructure provisioning. Improved CI/CD efficiency by migrating services from S3-based Lambda packaging to ECR container images and optimizing Docker multi-stage builds. Enhanced Kubernetes operational reliability by creating reusable Helm charts and modularized deployment methods.

Architected clean-delete process for multi-tenant Kubernetes clusters using Golang. Successfully transitioned third-party Docker images to secure internal images, ensuring uniformity across all Kubernetes services. Contributed to large Terraform codebase for managing Cloud Kubernetes Clusters. Authored custom Prometheus endpoint for Cluster Autoscaling metrics in Golang. Created Golang Operators and CRDs for managing cloud infrastructure.

Implemented custom Terraform Providers to facilitate Hybrid Cloud Computing infrastructure at Twitter. Designed and build Terraform module for private AWS EKS deployment inside of Twitter VPC. Contributed to the successful evaluation of Golang as the primary non-JVM language at Twitter. Build automation tools in Golang for GitOps and compute infrastructure. Reduced time to provision the Terraform Enterprise server infrastructure from 4 hours to 5 minutes. Led cost-savings initiatives for compute and storage in GCP. Contributed to Golang Auth add-on tool for AWS EKS.

IT consulting providing freelance expertise on building and deploying web services

Created and led a software development team for a multi-billion dollar company. Championed and implemented Cloud Web Services, Agile Development Team, Data Warehouse, BI Reporting Platforms, Containerization, CI/CD Pipelines, and Serverless Web Applications. Created Golang Rest APIs, semi-structured text processors, email notifications, and GraphQL services. Systemized corporate data through Django Web Admin toll and Kubernetes Airflow.

Programmed asynchronous data pipelines to move data from Data Mart to Microsoft SQL, ElasticSearch, OpenTSDB, Postgres, and Oracle. Refactored Airflow to allow DAGs to launch from any folder without Webserver and Scheduler overhead. Authored Django web application to collect offline field data and sync with ElasticSearch. Refactored Python processes in Golang to improve speed and performance

Data Scientist/Software Engineer for a large-scale data migration project. Programmed python processes to automate data pipelines in Hadoop and MySQL for ETL, reporting, and analytics. Used Airflow and Bash scripting to steamline and automate. Experience with Spark, ElasticSearch, Impala, and provisioning a Hadoop cluster. Created asynchronous Python processes that retrieve and process data from FTP sites into HDFS. Authored TensorFlow Neural Network algorithm to classify image data. Used Natural Language Processing and Machine Learning to automate data migration. Developed Django UIs to enable non-programmers to interact with data and streamline processes. Used statistical techniques to provide insight into data landscape and drive business decisions.

Special data consultant on the Aliso Canyon Gas Leak Disaster. Self-taught Python to streamline the ETL efforts of relocation data. Spearheaded data and analytics and Interacted directly with VPs to provide updates on the relocation efforts and wrote algorithms to verify more that $20M in claims reimbursements.

Created and implemented VBA macro-enhanced verification sheets that were adopted in all Halliburton districts in the Rockies while managing and mentoring a team of 5 engineers. This position required 24-hour availability to support cementing operations in the lab and field. Invented a variable density/viscosity fluid system and programmed data-smoothing algorithms that lead to increased productivity.

Worked directly under the CEO to interpret historical sales data and predict budget and shipment needs. Created and maintained up-to-date market trackers and business reports and self-taught VBA to automate this process. Efforts lead to the replacement of Salesforce with in-house reporting tools.

Automatically generate course profile stickers for endurance races from .gpx and .fit files. Stack: Golang, GraphQL, Postgres, Python, Vue, Terraform, and AWS.

Scrape user emails for receipt data and generate JSON manifests of user inventory using the ChatGPT API. Users can then sell and/or manage their stuff inventory. Stack: Golang, GraphQL, Postgres, NextJS, Terraform, and AWS.

Annual scavenger hunt at Buttermilk Ski Resort. Users authenticate and are automatically assigned teams. Points are scored by scanning QR codes across the ski resort. Stack: Golang, GraphQL, Postgres, Vue, Terraform, and AWS.