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Ander Garro Abrain

Senior Data Engineer at Wizeline · Data and software engineering

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Fields of practice

Where I do my best work

Each area links to the experience and case studies behind it.

Selected case studies

Problems, decisions, trade-offs

Case studies written as engineering records, not marketing copy.

All case studies
CS-01

Multi-tenant modernisation from PostgreSQL to Snowflake

Integration of each tenant's operational PostgreSQL data from a pricing platform into Snowflake, maintaining isolation between tenants and automating the onboarding of new clients.

Data platforms · Cloud architecture · Automation & AI

  • Snowflake
  • PostgreSQL
  • C#
  • .NET
CS-02

Performance and cost optimisation in Snowflake

Optimisation of numerous reports and of the daily C# processes that pre-compute their data with advanced queries, combining PostgreSQL and Snowflake according to compute needs; includes pruning, joins, data types, VARIANT columns and analysis of warehouse and storage costs.

Architecture & performance · Data platforms · Cloud architecture

  • Snowflake
  • PostgreSQL
  • SQL
  • C#
CS-03

Consolidation of legacy event data in Snowflake

Python tooling to discover, migrate, reconcile and validate older and newer generations of event tables across hundreds of tenant schemas, with hundreds of millions of records, without loss or duplicates.

Data platforms · Automation & AI

  • Python
  • Snowflake
  • SQL

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How I work

How I work

  1. 01

    Whole-system view

    Investigate every layer involved (storage, processing, services, infrastructure, security, APIs, deployment and analytics) before deciding where the problem is.

  2. 02

    Root cause before more resources

    A background in physics and applied mathematics translates into an analytical approach; understand the bottleneck before scaling or rewriting.

  3. 03

    Automate the repetitive

    Pipelines, tenant onboarding, validations, migrations, dependency discovery and AI-assisted development workflows are examples of manual work turned into automation.

  4. 04

    Cost and operations as requirements

    Reliability, maintainability and cost efficiency are assessed together, from warehouse usage to S3 storage.

  5. 05

    Explicit, documented decisions

    Technical investigations, architecture proposals, implementation plans, diagrams and QA evidence so the team can review and decide.

  6. 06

    Bridge between data and software

    Move comfortably between SQL optimisation, pipeline design, backend service implementation and cloud infrastructure.

Collaboration

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