Go or PostgreSQL Slowing Down? Find the Bottleneck Before a Rewrite

If your Go application or PostgreSQL database slows down when the business gets busy, start by tracing the work that is failing. A larger server, another index or a rewrite might help, but the symptom alone does not tell you which change to buy.

At Revitt we work with Go, PostgreSQL and the systems around them. We can work alongside your developers to investigate a defined problem, agree the improvement you need and deliver a scoped repair. That can begin with one slow report, an API that times out, an import that never finishes or jobs that keep failing and retrying.

Start with one business workflow

“The database is slow” is a starting observation. “Order imports take longer than the gap between deliveries, so the warehouse starts with yesterday’s stock” gives the investigation a useful boundary.

Choose one affected workflow and record when it fails, who it affects, the load at the time and what acceptable behaviour would look like. Include a typical busy period and the awkward cases. A fast average response can hide a small number of very slow requests; response-time percentiles, failures and waiting work help describe that difference.

Then follow the request or job through its actual path: application, database, other services and the screen or output the person needs. Waiting for a connection, waiting on another transaction and doing expensive computation call for different repairs.

What we would inspect

Use these symptoms to choose the first evidence to collect.

What you see	What we would inspect	The decision it helps make
A Go service gets slower and uses more memory over the day	Memory profiles, retained objects, queues and the lifetime of work	Fix retained data or unbounded work before buying capacity
Requests stall while CPU looks quiet	Connection waits, goroutine state, locks and downstream calls	Find where work is waiting before adding workers
A report is fast on a small database and slow on the real one	Query plan, rows processed, indexes and the actual data distribution	Change the query or data access based on its real workload
Updates block one another	Transaction length, lock waits and competing jobs	Reduce contention without breaking business rules
An import retries and creates duplicate or missing records	Job ownership, transaction boundaries, deduplication and failure recovery	Make processing dependable before increasing throughput
A release made the service slower	Comparable before/after traces, profiles and deployment changes	Repair or roll back the specific regression

Go provides CPU, memory and other profiles, plus tracing, for different diagnostic questions. These tools need deliberate selection: collecting several kinds of detailed diagnostics together can distort the result. The Go diagnostics guide explains the distinctions. We agree how to collect evidence safely and keep diagnostic access private.

For PostgreSQL, an execution plan helps explain how a query is being run. EXPLAIN ANALYZE actually executes the statement and adds measurement overhead; it is not a harmless preview to run indiscriminately on production. See PostgreSQL’s explanation of query plans.

Where already available, pg_stat_statements can help identify expensive or frequently executed statements. Enabling it can require a server restart, so treat installation as planned operational work with the appropriate owner. PostgreSQL documents the requirements.

A repair can cross the application and database

Consider an illustrative order-import job. It receives a file, calls an external system, writes records and retries when something fails. More workers could increase throughput, or they could exhaust the connection pool and repeat the same failing work faster.

We would examine how a job is claimed, which work belongs in a transaction, how retries recognise an order already processed and what happens after an interruption. We would also check that the person running the operation can see exceptions and recover them. The right result is a reliable completed import, including its awkward cases.

This is where application engineering, PostgreSQL and solution architecture meet. A database-only change can miss the retry behaviour; an application-only change can miss contention. Someone needs to own the whole workflow and its acceptance criteria.

What to agree for the initial investigation

Agree the investigation before changing the live system. A defined first piece of work should establish:

• The affected workflow, relevant load and agreed measures.
• The evidence collected, what it supports and what remains uncertain.
• A prioritised repair or further investigation, with scope and dependencies.
• Representative checks for correctness as well as speed.
• Deployment, recovery and handover responsibilities for any implementation.

A proposed improvement should be tested against comparable inputs and load. Include the business outcome, errors, completion time and running cost. A faster job that produces the wrong records has not passed.

When does a rewrite make sense?

Sometimes the existing design prevents the business from moving forward. Assess that against the cost and risk of repair, a staged replacement and a full rebuild. Include migration, integrations, staff use, rollback and who will own the result.

If several suppliers disagree about the architecture or the trade-offs are unclear, a defined architecture review or ongoing CTO remit may be the useful first step. If the decision is already clear, a scoped engineering engagement can stand on its own.

Our Gateway.FM case study describes a long-running infrastructure and engineering relationship. Global HRIS shows the work involved in turning a demanding reconciliation process into an owned product. They give you concrete work to discuss with us when judging the fit for your system.

Bring the problem to the first conversation

Tell us what the system does, what goes wrong, when it began and any deadline. You do not need to send credentials, customer records or a production database to start the conversation.

Revitt is based in Sheffield and works with teams across the UK. Discuss the system with Max; the initial call is free. We will explain the first step and agree the scope and price before paid work begins. Ongoing leadership and System Care have their own agreed terms.