Java, Kotlin, Nfc, Smartcards, Trusted execution environments, Cross-process communication in Android, Hardware integration on Android, Large-scale application design and architecture

Oracle, Scrum, Java, Dynamodb, RDBMS, Postgres, AWS, Cassandra, Kotlin, Nosql, Python, Azure, Gcp, Scala, Go, micro-services, Xp, agile software development methodologies