Inclusion Criteria (before leukapheresis)  Age 18 -75 years.  Histologically proven large B cell lymphoma or transformed follicular lymphoma to DLBCL in relapse/refractory after two lines of therapies which included an anthracycline and CD20-targeted therapy.  Chemotherapy refractory disease evidenced by lack of response to first line therapy, progressive disease as best response to first line therapy, stable disease as best response after 4 cycles of appropriate chemotherapy or refractory after ASCT with disease progression or relapsed ≤ 12 months after ASCT (biopsy-proven).  ECOG performance status 0-1.  Adequate hematologic, hepatic, renal and cardiac function evidenced by:  ANC ≥1000/µL Platelet ≥ 75,000/ µL T-bilirubin ≤ 1.5 mg/dL Creatinine clearance ≥ 60 mL/min/1.73 m2 Cardiac ejection fraction ≥ 50% Serum alanine aminotransferase/aspartate aminotransferase (ALT/AST) ≤ 2.5 upper limit of normal (ULN). At least 1 measurable lesion per Cheson 2014. Baseline oxygen saturation ≥92% on room air. Ability to stay at a distance which allows for subjects to come in and for specific interventions like antibiotics and tocilizumab to be started in 1 hour or less. This is 5 miles or 15-minute driving distance of Vanderbilt. Partner institution will abide by their standards for proximity to allow to allow for specific interventions to be started in 1 hour or less A caregiver who can be educated to operate equipment for vital signs monitoring.  Caregiver Eligibility:  Willingness to serve as a caregiver Ability to read, write and operate a phone Willingness to be taught to operate electronic device Willingness and ability to assist subject to wear electronic device such including patch, blood pressure machine, thermometer Pass caregiver assessment test  Subject and caregiver willing to be taught to operate an iPad or other electronic media for telemedicine, use wearable devices, and pass the caregiver competence test.  Low tumor burden with the sum of product diameter (SPD) < 100 cm2 by PET-CT scan.  Exclusion Criteria:  History of malignancy other than nonmelanoma skin cancer or carcinoma in situ (e.g. cervix, bladder, breast) or follicular lymphoma unless disease free for at least 3 years.  Known CD19 negative or CD20 negative tumor.  History of Richter's transformation of CLL.  Autologous stem cell transplant with therapeutic intent within 6 weeks of planned YESCARTA infusion.  History of allogeneic stem cell transplantation.  Prior CAR therapy or other genetically modified T-cell therapy.  History of severe, immediate hypersensitivity reaction attributed to aminoglycosides.  Presence or suspicion of fungal, bacterial, viral, or other infection that is uncontrolled or requiring IV antimicrobials for management. Simple urinary tract infection (UTI) and uncomplicated bacterial pharyngitis are permitted if responding to active treatment and after consultation with the sponsor's medical monitor.  History of human immunodeficiency virus (HIV) infection or acute or chronic hepatitis B or hepatitis C infection. Subjects with history of hepatitis infection must have cleared their infection as determined by standard serological and genetic testing per current Infectious Diseases Society of America (IDSA) guidelines or applicable country guidelines.  Presence of any in-dwelling line or drain (e.g., percutaneous nephrostomy tube, in-dwelling Foley catheter, biliary drain, or pleural/peritoneal/pericardial catheter). Dedicated central venous access catheters, such as a Port-a-Cath or Hickman catheter, are permitted.  Subjects with detectable cerebrospinal fluid malignant cells, or brain metastases, or with a history of CNS lymphoma or primary CNS lymphoma, cerebrospinal fluid malignant cells or brain metastases.  History or presence of CNS disorder, such as seizure disorder, cerebrovascular ischemia/hemorrhage, dementia, cerebellar disease, progressive multifocal leukoencephalopathy, or any autoimmune disease with CNS involvement.  Subjects with cardiac atrial or cardiac ventricular lymphoma involvement.  History of myocardial infarction, cardiac angioplasty or stenting, unstable angina, or other clinically significant cardiac disease within 12 months of enrolment.  Requirement for urgent therapy due to tumor mass effects (e.g., blood vessel compression, bowel obstruction, or transmural gastric involvement).  Primary immunodeficiency.  History of symptomatic deep vein thrombosis or pulmonary embolism requiring systemic anticoagulation within 3 months of enrollment. Line related DVT that is treated is not exclusionary.  Any medical condition likely to interfere with assessment of safety or efficacy of study treatment.  Live vaccine ≤ 6 weeks prior to planned start of conditioning regimen.  History of severe immediate hypersensitivity reaction to any of the agents used in this study.  Women of child-bearing potential who are pregnant or breastfeeding because of the potentially dangerous effects of the preparative chemotherapy on the fetus or infant. Females who have undergone surgical sterilization or who have been postmenopausal for at least 2 years are not considered to be of childbearing potential.  Subjects of both genders who are not willing to practice birth control from the time of consent through 6 months after the completion of conditioning chemotherapy.  In the investigator's judgment, the subject is unlikely to complete all protocol-required study visits or procedures, including follow-up visits, or comply with the study requirements for participation.  History of autoimmune disease (e.g. Crohn's, rheumatoid arthritis, systemic lupus) resulting in end organ injury or requiring systemic immunosuppression/systemic disease modifying agents within the last 2 years.  Must not have received immunomodulating agents including checkpoint inhibitors, BTK inhibitors, and Revlimid within 2 months or 5 half-lives whichever is shorter.