Tech Lead Basics on Postgres

8 examples to get you started with tech leadership on Postgres - 5 basic and 3 intermediate.

Prerequisites

psql "$DATABASE_URL" -c "SELECT version();"
psql "$DATABASE_URL" -c "SELECT count(*) FROM pg_stat_activity;"

• Read access to staging and production metrics (Grafana, pganalyze, or pg_stat_statements).
• A single schema style guide and migration tool for the org.
• Relationships with product, finance, and security for trade-off conversations.

Basic Examples

1. The Correctness / Uptime / Cost Triangle

Every decision moves one vertex at the expense of another.

• Document which vertex is non-negotiable per product line.
• Revisit quarterly when traffic shape changes.

Related: Uptime SLOs for Datastores - error budgets

2. Schema as Public API

Breaking schema changes are breaking API changes.

-- Breaking without expand/contract
ALTER TABLE invoices ALTER COLUMN amount TYPE numeric(10,2);  -- rewrite risk
 
-- Safer expand path
ALTER TABLE invoices ADD COLUMN amount_v2 numeric(12,2);
-- app dual-write, backfill, cutover, drop old column later

• Publish schema changelog for service owners.
• Require ERD or migration link in epic tickets.

3. Connection Math Ownership

Tech leads set pool policy; apps implement it.

max_connections = 200 on instance
PgBouncer pool_size = 80 per database
App pods = 40 x pool 20 = 800 client connections → MUST use PgBouncer

SELECT count(*), state FROM pg_stat_activity GROUP BY 2;

• Reject designs that open one connection per HTTP request without pooling.
• Plan capacity before Black Friday, not during.

Related: Connection Math - sizing formulas

4. Observability Minimum Bar

If you cannot see it, you cannot lead it.

CREATE EXTENSION IF NOT EXISTS pg_stat_statements;
 
SELECT query, calls, mean_exec_time, rows
FROM pg_stat_statements
ORDER BY total_exec_time DESC
LIMIT 10;

• Top-N query report in weekly engineering review.
• Disk growth forecast monthly with finance copy.

5. Escalation Paths

Clarify who decides under pressure.

• Pre-approve termination policy for idle in transaction.
• Never improvise RACI during Sev-1.

Related: Incident Basics - roles

Intermediate Examples

6. Cross-Team Schema Council

Weekly 30-minute forum for shared database.

## Database Council Agenda
1. Pending migrations (risk tier)
2. Index requests queue
3. Incident learnings
4. EOL and extension upgrades

• Representatives from each service using the database.
• Veto only on correctness/safety, not taste.
• Output: ADR links and approved migration order.

7. Technical Debt Register

Track data-layer debt like application debt.

| ID | Item | Risk | Owner | Target |
|----|------|------|-------|--------|
| DB-12 | Missing FK on refunds.order_id | correctness | payments | Q3 |
| DB-18 | orders_seq_scan 40% CPU | cost | platform | Q2 |

SELECT relname, seq_scan, idx_scan
FROM pg_stat_user_tables
WHERE seq_scan > idx_scan AND seq_scan > 10000;

• Tie debt burn-down to error budget recovery after incidents.

8. Hiring and Delegation

Tech lead owns standards; staff+ DBAs own execution depth.

• Interview loop includes SQL review and incident scenario.
• Pair new leads with DBA on first high-risk window.
• Grow internal runbook authors, not single hero on-call.

Related: Career Growth: DBA → Staff Data Engineer - growth path

Stack versions: This page was written for PostgreSQL 18.4 (stable 18, maintenance 17), pgvector 0.8+, PgBouncer 1.x, Patroni 3.x, and PostGIS 3.5+.