Question 1

Performance Engineer vs Site Reliability Engineer - what is the actual difference?

Accepted Answer

Performance Engineers focus on design and run load and stress tests. Site Reliability Engineers focus on define and own slos and error budgets. The two roles are often confused because they sit next to each other in modern delivery teams, but the day-to-day work, the success metric and the interview rubric are not the same.

Question 2

Which is easier to hire - a performance engineer or a site reliability engineer?

Accepted Answer

Both pools are active on Haystack. First shortlists land within 24 hours of kick-off for either role. Compensation varies by sector and seniority; we benchmark every offer against live UK, DE and US data.

Question 3

Can the same person cover both performance engineer and site reliability engineer work?

Accepted Answer

Often partially. Senior generalists carry one as their primary discipline and one as supporting, but expect a 60/40 split rather than 50/50 - the deep work in either role rarely happens in the same week. If the workload sustains, hiring one of each is almost always the better long-term call.

Question 4

What skills should I screen for in a performance engineer interview?

Accepted Answer

Anchor the rubric on k6, JMeter, Profilers. We surface every Haystack profile with the specific tooling, levels and shipped-work examples so you can shortlist against a real skills bar, not buzzwords.

Question 5

What skills should I screen for in a site reliability engineer interview?

Accepted Answer

Anchor the rubric on SLOs, Observability, Incident response. As with the performance engineer role, the easiest way to compare candidates is a 90-minute paid take-home that mirrors real work - never a trivia quiz.

Question 6

Do you cover senior and lead-level performance engineers and site reliability engineers?

Accepted Answer

Yes - the full ladder from junior through staff/principal in both. The kick-off call captures the level and shipped-work bar you need, and shortlists are filtered accordingly.

Dimension	Performance Engineer	Site Reliability Engineer
Category	QA & Support	DevOps
Mid-level UK base	£68k–£92k	Tailored
Senior UK base	£98k–£135k	Tailored
Primary focus	Design and run load and stress tests	Define and own SLOs and error budgets
Core skills	k6, JMeter, Profilers, Tracing	SLOs, Observability, Incident response, Kubernetes
First shortlist	24 hours	24 hours

Performance Engineer vs Site Reliability Engineer

Performance Engineer

Site Reliability Engineer

Performance Engineer vs Site Reliability Engineer - at a glance

Performance Engineer vs Site Reliability Engineer - common hiring questions

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