Hire senior SQL developers for fast, correct database code
Senior SQL developers who tune slow queries, write stored procedures and design schemas on SQL Server, Postgres, Oracle or MySQL, embedded in your team on US hours.
By the Ryz Labs team · Updated October 2026
Hiring SQL developers through Ryz gets you senior Latin American engineers who write database code that is correct under concurrency and fast at production volume. They are top 1% of the candidates we interview, they embed in your team and repos, and they work within an hour of US time zones.
What our SQL developers work on
Our SQL developers work in the database engine itself: T-SQL on SQL Server and Azure SQL, PL/pgSQL on PostgreSQL, PL/SQL on Oracle, and MySQL. They use execution plans, Query Store, pg_stat_statements, SSMS, Azure Data Studio or DBeaver, and migration tools like Flyway, Liquibase or EF Core migrations. Typical projects:
- Finding and fixing the slow queries behind application timeouts and report delays.
- Maintaining and refactoring large stored procedure codebases that run core business logic.
- Schema design for new features, including constraints, indexes and data types chosen for growth.
- Zero-downtime migrations on large tables: backfills, column changes and index builds without locking users out.
- Database platform moves, such as Oracle to PostgreSQL or SQL Server to Azure SQL, with code conversion and testing.
- ETL and reporting work in SSIS, stored procedures or scheduled jobs feeding BI tools.
- Deadlock and blocking investigations in high-concurrency transactional systems.
Skills we vet for
- Execution plans. Reading actual plans, spotting scans, key lookups, bad join choices and misestimated row counts.
- Indexing. Clustered and nonclustered, covering and filtered indexes, partial and expression indexes in Postgres, and the write cost of each.
- Set-based thinking. Replacing cursors and row-by-row loops with set operations, window functions and CTEs.
- Concurrency. Isolation levels, locking and row versioning, deadlock graphs and designing transactions to stay short.
- Parameter sensitivity. Parameter sniffing, plan caching, statistics updates and when to use query hints.
- Schema design. Normalization, sensible denormalization, constraints that protect data, and partitioning for large tables.
- Procedural code. Stored procedures and functions with error handling, transactions and tests using tools like tSQLt or pgTAP.
- Change management. Versioned migrations, rollback plans and reviewing database changes like application code.
How we vet SQL developers
Our recruiters source developers who have tuned and maintained production databases under real load. Our in-house ARC system ranks the pipeline, and candidates complete structured NTRVSTA AI interviews built around query plans, concurrency and schema change scenarios. Recruiters review every candidate before and after, then send a curated shortlist. AI scores are advisory, and humans make the decisions.
Sample interview topics
- A stored procedure runs in one second for most customers and two minutes for one large customer. What is happening, and how do you fix it?
- Add a NOT NULL column with a default to a 500-million-row table during business hours. How do you do it safely on your engine of choice?
- Two transactions deadlock every few minutes at peak. Walk through reading the deadlock graph and the changes you would consider.
- Rewrite a cursor that calculates running balances per account into a set-based query, and explain the performance difference.
- An index was added to fix one query and three other queries got slower. How could that happen?
Ways to hire SQL developers
| Option | Best for | Trade-offs |
|---|
| Freelance marketplace | Tuning a single query or writing one report | Database code holds business logic. Short-term fixes without context can cause new problems elsewhere. |
| Staffing or recruiting agency | Roles with a specific engine and version list | Most resumes list SQL. Few screens test plan reading or concurrency. |
| In-house recruiting | A permanent database or data team | Slow to staff, and deep SQL skill is hard to assess without a senior DBA interviewing. |
| Ryz Labs staff augmentation | Adding senior SQL developers to your backend or data team | You own the schema and release process. Works best with access to production-like data for testing. |
| Ryz Labs dedicated team | A database migration or modernization with application changes | A dedicated team of database and backend engineers. Scoped as a team with a plan up front. |
If you need a managed DBA service with 24/7 coverage from multiple continents, or a short hourly gig through a self-serve marketplace, Ryz is not the right fit.
Why hire SQL developers from Latin America
Database problems tend to surface at peak usage, which is during your business day. A SQL developer working your hours can watch blocking happen live, capture the plan while it is slow and coordinate an index change with your application team in the same afternoon.
Senior SQL developers in the region have maintained large transactional systems for retailers, insurers, payments companies and logistics businesses, where stored procedures often hold years of business rules. They document changes clearly in English and work closely with your backend engineers and analysts.
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FAQ
Which database engines do your SQL developers know?
SQL Server and Azure SQL, PostgreSQL, Oracle and MySQL are the most common. Most are deep in one or two engines, and we match them to the one you run.
Can they help with a migration from Oracle or SQL Server to PostgreSQL?
Yes. Code conversion, data type mapping, testing for behavior differences and cutover planning are all part of what they handle, together with your application team.
How is pricing set?
Custom quote, scoped per team. You get a scoped plan, a price and the names of the people before you sign.
Who is the contract with, and what hours do they cover?
You sign one contract with Ryz. Our engineers work with us as independent contractors, and we handle paying them. They work within an hour of US time zones.
Is a SQL developer the same as a DBA?
Not quite. SQL developers focus on queries, procedures and schema. DBAs focus on backups, high availability, security and server configuration. Many senior SQL developers cover both to a degree, and we will tell you which profile fits.
Questions we didn't answer? Email info@ryzlabs.com.