A guide to hiring PostgreSQL developers
PostgreSQL, often called Postgres, is a free, open source database used by start-ups and large companies. It holds the orders, accounts and content behind many web and mobile products. Because it offers many data types, index types and extensions, results depend a lot on the person who sets it up. This guide explains what PostgreSQL developers do, how the role differs from nearby roles and how to organize the work. It suits a founder planning a first product as well as a team whose Postgres database has started to slow down.
What PostgreSQL developers work on
Most Postgres work falls into four groups. Design covers tables, keys, constraints and data types. Speed covers indexes, query rewrites and settings that affect how fast pages load. Features cover things Postgres can do for you, such as JSONB columns, full text search, maps with PostGIS and similarity search with pgvector. Change covers migrations, upgrades and moves from other databases. On a young product one person usually covers all four, and as the team grows the jobs get shared.
How this role differs from nearby roles
A PostgreSQL developer builds on one engine in depth. Our SQL developer page is about queries, reports and design across engines. Our database engineer pages are about keeping databases safe and online, and our Postgres DBA page covers that duty for software companies. If your Postgres data feeds pipelines and warehouses, our data engineer page may help. App teams can also add back-end developers to write the code around the database.
Where Postgres can run
- On your own servers, where your team handles installation, patches and backups.
- On a managed service such as Amazon RDS or Aurora, Google Cloud SQL or Azure Database for PostgreSQL, where the provider handles much of the routine work.
- In containers on a platform such as Kubernetes, which suits teams that already run their other services that way.
- On a laptop or test server, where your developer can try changes safely before they reach real users.
Say early where yours runs. It changes which settings your developer can touch and which tools they use.
What to decide before you hire
- Which Postgres version you run, and whether an upgrade is planned.
- Whether the main goal is speed, a new feature, a migration or general care.
- Which languages and frameworks the application uses on top of the database.
- Whether a copy of the data is enough, or the developer needs a live read-only account.
- Who handles backups and on-call duty, so the two roles do not overlap or leave a gap.
Reading a PostgreSQL developer’s profile
Ask for specifics. A good candidate can describe a slow query they fixed, show the plan before and after and explain why the fix worked. Look for experience with live migrations, not only fresh projects. Be careful with profiles that name every database but cannot say what they did in each. Ask what they would do differently on a past schema. Someone who can name a design mistake and what it taught them is a safer hire than someone who claims they never made one.
Interview questions to try
- How do you find out why one query is slow, and what do you try first?
- When would you choose a GIN index over a B-tree index?
- How do you add a column with a default to a very large live table without blocking users?
- What are the trade-offs of storing data in a JSONB column?
- Tell us about a time a long-running transaction caused trouble. How did you spot it?
Good answers name a step, a tool and a result. Be wary of anyone with one fix for every slow query.
Run a small paid task
Set each finalist a short task drawn from your own product. Fair choices include a slow endpoint with the query and table definitions attached, a schema review for a new feature, or a plan to move one table to a partitioned layout. Pay for the hours. Judge how well the person explains the cause, how safe the change looks and how they would check it.
Match experience to the stage
A prototype needs a clean schema built fast and kept plain. A product with growing traffic needs strength in indexing, tuning and careful change. An older product needs steady care for upgrades, huge tables and team habits such as reviewing every migration. Titles vary a lot, so ask what a candidate actually owned.
Give them tools and a rhythm
Open a staging database, the slow-query logs and the code repository to your developer, and nothing beyond what the job needs. Keep production passwords inside your company. During month one, meet weekly and walk through every schema change together. Later, a weekly note plus a review of each migration before it runs is enough.
Working with your application team
Many database problems begin in application code, such as a page that runs one query per row. A PostgreSQL developer should read that code, not only the database. Agree that schema changes go through the same review as code changes, and that new queries on busy pages are checked with a plan before release. Keep a short list of rules, such as how to name tables and when to add an index, so that new team members follow the same habits.
Mistakes to avoid
- Adding indexes everywhere without checking which queries use them.
- Running schema changes on a busy live table without a plan for locks.
- Putting every field into one JSONB column and losing the checks that normal columns give you.
- Skipping version upgrades until the old version is no longer supported.
- Handing a contractor the only owner login for your database, backups or cloud billing.
Need help with the servers as well, or with reports across engines? Read about how to hire a database engineer or a SQL developer, and see how hiring works on our pages.