Server-side experiments
We set up server-side experiments: variant assignment and test logic run on the server, not in the browser. This removes variant 'flicker', lets you test not only the interface but also logic, prices, algorithms, and is more resilient to blockers. Honestly upfront: this is more reliable and engineering-complex testing infrastructure, not a guarantee of conversion growth; and it requires developer involvement.
Server-side experiments — overview
Server-side experiments is an engineering project: we implement variant assignment and event capture on the server/backend, integrate with your feature-flag system or experiment tool, ensure consistent user allocation, deduplication and correct metric collection. Honestly about the benefits and when this is needed: server-side removes flicker (flashing of the control variant), works where client-side is powerless (pricing, business logic, algorithm output, mobile/no UI) and is more resilient to blockers — that is its real value. Honestly about the method's cost: it is more complex and expensive than client-side A/B, requires developers and code access; for simple interface tests it is overkill — we honestly say a regular A/B is enough. Honestly about the result: like any experiment, server-side validates a hypothesis and does NOT guarantee growth — 'no difference' or a worsening is possible; traffic, significance and discipline (no 'peeking') are needed. Honestly about data: correct event tagging is mandatory (garbage in, garbage out). Honestly about the essence: this is infrastructure and running tests, NOT rolling out the winner and NOT guaranteed growth — decisions and rollout are done by you. The feature-flag/experiment platform (if paid) is separate. An important boundary: these are server-side experiments, not client-side A/B (simpler — separate), not edge experiments (on the CDN — separate) and not building the variants themselves. If you test only the interface and traffic is modest, server-side is overkill. Picture this: instead of 'the variant flickers and prices and logic can't be tested at all' you test correctly and deeper — where it is justified. The base price starts from 30,000 ₽ per project; it depends on integration and complexity.
Problems we solve
- The control variant 'flickers' in client-side tests (flicker).
- You cannot test prices, logic, algorithms via the browser.
- Blockers and slow JS distort client-side tests.
- You need to test where there is no interface (API, mobile).
What's included in the Server-side experiments service
- Server-side variant assignment and event capture
- Integration with feature flags/an experiment tool
- Consistent user allocation and deduplication
- Correct metric collection and guardrail control
- An assessment: do you need server-side or is client-side A/B enough
- An honest significance analysis (including 'no difference')
- Documentation and access
- Reviewing results with you
What you get
- Tests without flicker and more resilient to blockers
- You can test logic, prices, algorithms, not just UI
- Correct experiment data
- A base for decisions (implementation and growth — separately)
How the work goes: steps
- We clarify what is tested and whether server-side is needed; collect code access
- We implement variant assignment, integration and metric collection
- We launch, analyze significance, give an honest conclusion
Why PDV Expert
- Fixed price and timeline — no surprises on the invoice.
- Report and recommendations in plain language — clear without a technical background.
- In touch at every step and answering questions about the result.
FAQ
Do server-side experiments guarantee a conversion increase?
No. It is more reliable testing infrastructure, but an experiment still validates a hypothesis rather than guaranteeing improvement — 'no difference' or a worsening is possible. Traffic and significance are needed.
How is this better than a regular A/B?
Server-side removes flicker, resists blockers and lets you test prices, logic and algorithms, not just the interface. But it is more complex and expensive; for simple UI tests on modest traffic a regular client-side A/B is more honest.
Can this be done without developers?
No. Server-side experiments require code access and developer involvement (yours or ours). If that is not possible, consider client-side A/B — we honestly advise.
About the provider
The «Server-side experiments» service is provided by PDV Expert — a team specialising in «Conversion & analytics». We work under contract and deliver a written report with recommendations.