here's my (approximate) transcript of Mar 22, 2016 telecon between Biden and Poroshenko: see https://twitter.com/golovaOPU/status/1262700044656021508. It is certain that there was a Mar 22, 2016 call between them.

2/ Biden made the call from Air Force Two. (This detail lost in Ukrainian transcription). Shokin was fired on Mar 31, within 10 days. Poroshenko mentioned Lutsenko as candidate replacement and indeed Lutsenko proved to be replacement.

3/ in Feb and early Mar 2016, Blue Star Strategies, high-level Dem fixers associated with Hunter Biden, had met with State Dept officials prior to Joe Biden call. They met with Shokin's replacement in April, immediately after Shokin fired
https://twitter.com/search?lang=en&q=blue%20star%20(from%3Aclimateaudit)&src=typed_query

4/ Blue Star Strategies, together with John Burretta, a former Obama DOJ official, then arranged that all Burisma legal problems in Ukraine were disappeared, announced in Jan 2017 in very last days of Obama admin. More or less at same time as Obama admin attacking Flynn.

5/ immediately after Burisma legal problems in Ukraine were disappeared, Burisma became a major sponsor and donor to Atlantic Council.

6/ https://twitter.com/golovaOPU/status/1262694685514108929

7/ the above video is from Feb 18, 2020. This is also the confirmed date of a critical call between Biden and Poroshenko in heat of campaign to fire Shokin, the prosecutor who was investigating Burisma https://ua.usembassy.gov/readout-vice-president-bidens-call-president-petro-poroshenko-ukraine-021816/

8/ https://ukranews.com/en/news/703227-poroshenko-boasted-to-biden-that-he-had-raised-tariffs-by-100-instead-of-the-required-75-a-record
h/t mzishi

9/ there's a half hour of tapes here https://www.youtube.com/watch?time_continue=2&v=JXUhGMuhYCM&feature=emb_logo

10/ in the half hour of tapes, towards end, there's a Nov 16, 2016 call (concealed from US Embassy list of read outs)
https://ua.usembassy.gov/news-events/page/107/. In this call, Biden urged Poroshenko to complete closing a transaction before Trump found out about it.

11/ the transaction was being done through Kolomoisky's Privatbank - both mentioned by Biden. According to Alexander Cockburn in Harper's in 2015, https://harpers.org/2015/08/undelivered-goods/,
Kolomoisky and his partner had embezzled US$1.8 billion (!!) from IMF loans arranged by Biden et al.

12/ the failure of Obama-Biden administration to prosecute this enormous embezzlement (while being very persistent in prosecuting oligarch Firtash for much, much smaller and less clear corruption charge in India (?!?), always seemed odd to me.

13/ so the call between Biden and Poroshenko AFTER election, off record of State Dept, urging closure of a transaction involving Kolomoisky's Privatbank before Trump found out is a definite dig-here