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When the database
is the business.

Zero-downtime migrations, consolidation and performance rescue on multi-terabyte transactional systems — done in production, with the business running. Three decades of the depth most modern architects never built.

/ 01 — The problem

The riskiest projects are
the ones that can't stop.

Every company has one: the database that runs the business and terrifies everyone. The migration postponed for years because nobody will own the risk. The system that collapses under every peak. The estate of servers accumulated through a decade of “temporary” decisions. The application whose authors left long ago, with the business logic buried in a thousand stored procedures.

The standard industry answer — “rewrite it” — is usually the most expensive and most dangerous option on the table. The engineering answer is to migrate, consolidate and optimize what runs the business, without stopping it, with verification instead of hope.

/ 02 — What I do

Engineering,
not heroics.

The discipline is always the same: empirical verification, rehearsed cutovers, performance proven under production load. And the hands are mine — I write the scripts, run the migrations and execute the cutovers personally. The accountability stays with me.

/ 01

Zero-downtime production migrations

Version upgrades, platform moves and server consolidation executed hot, on live systems. Method: 100% test coverage of migrated code, full data and view verification, performance validated under production-equivalent stress, rehearsed cutover.

Track record includes CMMI-III environments and systems with millions of sales per hour. Zero incidents.

/ 02

Performance engineering at scale

Multi-terabyte transactional databases: partitioning, indexing strategy, T-SQL surgery on business logic, aggregate architectures for systems ingesting hundreds of millions of events per year.

When the report takes hours and the hardware is fine, the problem is the code — and it's fixable.

/ 03

Data integration & replication

Warehouse feeds and replicas that stay correct: AWS DMS orchestration, custom integration controllers, change tracking, checksum-verified incremental sync — automated to remove the human error from the loop.

I've published my own tooling here: sqlDataTrans, czAsyncSQLServer, Git version control for SQL Server.

/ 04

Critical & orphaned systems

Mission-critical code thousands of users depend on — elusive bugs, integration failures, data corruption, performance collapses. Including orphaned systems whose original developers are long gone: study the code, document it, then extend it safely.

Brought in when others couldn't crack it. That's usually the brief.

/ 03 — Engagement shapes

Built around
the risk.

100% remote, in English or Spanish, for clients primarily in North America and Europe. The entry point is almost always the audit — small, fast, and it tells you the truth.

/ Shape · 01

Database estate audit

Short, fixed-scope review of the estate: real risks, performance headroom, consolidation opportunities and a defensible migration path — written for both engineering and leadership.

/ Shape · 02

The migration nobody wants to own

Full ownership of a zero-downtime migration or consolidation: plan, verification framework, rehearsals, hot cutover, and my name on the outcome.

/ Shape · 03

Performance rescue

For systems that are collapsing under load or growth: diagnose the real bottleneck in the code and the schema, fix it in production, leave the evidence.

/ Shape · 04

Embedded senior for critical systems

Ongoing senior authority over a database estate or critical application — architecture decisions, code review, the person your team calls before touching production.

/ 04 — Proof

Done in production.
With the lights on.

A selection from the full project history — each row links to the detailed record.

001
Telepizza — hot migration & consolidation, 12 servers to 2 Spain's biggest web-sales bursts at the time — millions of sales per hour before football games. SQL Server 2000 to current, 100% T-SQL coverage, zero incidents.
Telepizza
Zero-downtime Consolidation
002
ALK Abelló — CMMI-III production migration, 100% test coverage Pharma-grade discipline: empirically verified migration of code, views and data on live production. On budget, on schedule, client congratulations on record.
ALK Abelló
CMMI-III Zero-downtime
003
Madrid — telecontrol of public lighting & fountains 2 TB SQL Server Enterprise, 3,000+ PLCs, 126,000 lighting points, 400M+ events and measures a year — near-real-time supervision plus warehouse and BI on top.
Ayuntamiento de Madrid · SICE
2 TB 400M events/yr
004
Iberdrola — share sale platform for 100,000+ employees 90% of each sale window's volume landing in the first two hours — with legally binding digital certificates issued in the middle of it.
Iberdrola
Burst load SQL Server
005
nVent / Eldon — AWS-DMS integration controller for BI Automated the entire replication lifecycle — task creation, parallel full loads at wire speed, sync validation — down to minimal human interaction, no chance of error.
nVent Hoffman
AWS DMS Automation
006
Dynamic IBM MQ listener & load-balancing system Re-architected a securities-lending platform's message processing: self-monitoring queues, intelligent failover, listeners that scale themselves.
Securities lending platform
IBM MQ Distributed
007
Aqua Data Studio — platform modernization, 30+ database engines Multi-release modernization of a commercial database IDE: JDK migration, IPv6 across 30+ connection types, drivers for Oracle, PostgreSQL, DB2, Snowflake and more.
Enterprise tooling vendor
Cross-DB Java
/ 06 — FAQ

Asked before
every engagement.

The questions that decide whether a migration gets approved — answered straight.

Zero downtime — really?

Yes, as an engineering discipline rather than a slogan: 100% test coverage of migrated code, full data and view verification, performance proven under production-equivalent load, rehearsed hot cutover. Delivered that way for Telepizza and ALK Abelló. Zero incidents, on record.

Which engines do you cover?

Deepest on SQL Server — multi-terabyte transactional systems, partitioning, T-SQL at business-logic scale. Cross-DB reach across Oracle, PostgreSQL, DB2, Snowflake and more (including years modernizing a database IDE that supports 30+ engines), plus NoSQL, vector databases and OpenSearch.

Our system is orphaned — its authors are gone. Can you work on it?

That's a specialty. I've repeatedly taken over undocumented production systems with no support from the original developers — studied the code, documented the platform, then extended it safely while thousands of users kept working.

How does an engagement start?

A conversation through LinkedIn, then usually a short health audit of the estate — risks, performance headroom, migration path — before committing to the larger project. Remote, primarily North America and Europe.

Have a database
everyone's afraid of?

That's exactly the kind I've spent three decades with. Tell me about it — the audit that answers “how bad is it really?” takes weeks, not quarters.