Russian payments firm Qiwi now estimates it could upgrade its core database to a distributed ledger system by 2021.

In an interview with Rambler News Service, a representative for the company said that this projection is in line with estimates that the full transition to any new technology takes about three years after a successful trial.

The statements, widely covered in Russian media, follow Qiwi's announcement of the trial in May.

At this time, Qiwi representatives told CoinDesk in detail why the company is building a private blockchain system as part of a bid to increase the transparency, accountability and efficiency of its services.

In the latest remarks, Qiwi CTO Alexey Arkhipov provided more detail about how the ultimate switch to the system could take place.

Arkhipov said an interim period would likely be needed to transition its older, centralized database out of use, though he added that the two systems could operate side by side for as long as a year to avoid issues.

Arkhipov told the news source:

Qiwi office image via Qiwi