Balance Sheet Components
 12 Months Ended
Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Balance Sheet Components
4.
Balance Sheet Components
Property and Equipment, Net
Property and equipment, net consisted of the following:
 
   
March 31,
2021
   
March 31,
2020
 
   
(in thousands)
 
Computer and software
  $13,252   $13,364 
Laboratory equipment and software
   48,636    49,367 
Furniture and office equipment
   8,803    8,868 
Leasehold improvements
   39,668    39,713 
Capitalized asset retirement obligations
   853    853 
  
 
 
   
 
 
 
Property and equipment, gross
   111,212    112,165 
  
 
 
   
 
 
 
Less: accumulated depreciation and amortization
   (50,328)    (34,283) 
  
 
 
   
 
 
 
Property and equipment, net
  $60,884   $77,882 
  
 
 
   
 
 
 
Depreciation and amortization expense were $18.1 million, $22.2 million and $9.9 million for fiscal years ended March 31, 2021, 2020 and 2019, respectively.
 
Assets Held for Sale
The Company’s assets held for sale consisted of $2.9 million of lab equipment as of March 31, 2020, which was subsequently sold at the carrying value during the fiscal year ended March 31, 2021.
Asset Retirement Obligations
The Company has recorded AROs related to contractual obligations to return the Sunnyvale, California headquarters facility to its original condition at the end of the lease term. Obligations are reflected at the present value of their future cash flows. The asset retirement obligations are depreciated on a straight-line basis over the useful lives of the related assets. The liability amounts were based on future retirement cost estimates and incorporate many assumptions such as time to abandonment, technological changes, future inflation rates and the risk-adjusted discount rate.
The following table summarizes changes in the Company’s AROs:
 
   
March 31,
2021
   
March 31,
2020
 
   
(in thousands)
 
Balance, beginning of year
  $1,078   $—  
Accretion expense
   87    41 
Liabilities incurred
   —     1,037 
  
 
 
   
 
 
 
Balance, end of year
  $1,165   $1,078 
  
 
 
   
 
 
 
Internal-use Software, Net
 
   
March 31,
2021
   
March 31,
2020
 
   
(in thousands)
 
Capitalized internal-use software
  $9,200   $5,839 
Less: accumulated amortization
   (2,311)    (422) 
  
 
 
   
 
 
 
Internal-use software, net
  $6,889   $5,417 
  
 
 
   
 
 
 
For the fiscal years ended March 31, 2021 and 2020, amortization expense related to internal-use software was $2.0 million and $0.4 million, respectively, including approximately $0.3 million and $0.1 million, respectively, of stock-based compensation expense. Impairment to internal-use software was $0.5 million and $0.7 million for the fiscal years ended March 31, 2021 and 2020. There was no amortization or impairment for the fiscal year ended March 31, 2019.
Accrued Expense and Other Current Liabilities
Accrued expense and other current liabilities consisted of the following:
 
   
March 31,
2021
   
March 31,
2020
 
   
(in thousands)
 
Accrued payables
  $19,869   $23,625 
Accrued compensation and benefits
   11,749    10,378 
Accrued taxes and other
   335    657 
  
 
 
   
 
 
 
Total accrued expenses and other current liabilities
  $31,953   $34,660 
  
 
 
   
 
 
 
 
Other Liabilities
Other liabilities, noncurrent consisted of the following:
 
   
March 31,
2021
   
March 31,
2020
 
   
(in thousands)
 
Asset retirement obligations, noncurrent
  $1,165   $1,078 
Liabilities for early exercise of common stock options by related party
   —     43,821 
  
 
 
   
 
 
 
Total other liabilities, noncurrent
  $1,165   $44,899