WARNING: The following contains spoilers for Star Wars: War of the Bounty Hunters - Jabba the Hutt #1, on sale now from Marvel.
Although the bounty hunter Boba Fett already had an extensive resume the first time he was hired by Jabba the Hutt, he still had to prove himself worthy enough to be included in the inner circle of the renowned alien gangster.
War of the Bounty Hunters - Jabba the Hutt #1 by Justina Ireland, Ibraim Roberson, Luca Pizzari, Edgar Delgado, Giada Marchisio and Ariana Maher revealed one of Boba Fett's earliest missions for Jabba the Hutt. The Hutt had called in one of his go-to bounty hunters, Deva Lompop to track down Jarm Brock, an enforcer that the gangster believed was placed by his opponents in the Hutt Council. Jabba tasked his then favorite bounty hunter with eliminating the threat and recommended that she take Fett along with her. The senior bounty hunter was not happy by this arrangement, but nevertheless complied with her employer's request.
When Jabba decided he wanted Jarm alive, Fett took the lead. He and Deva rode straight into Mos Entha to the local bar where they asked for information. This brought their target out of hiding, and Fett was able to take him down. Before the young bounty hunter could load his catch on his speeder, however, he was betrayed by Deva who poisoned him and knocked him unconscious. She then learned of Crimson Dawn's return and devoured Jarm while her partner was incapacitated. She then brought Fett back to Jabba who rescinded the deal he made with her due to Fett's condition and the death of their target.
As this was Deva's final mission for Jabba before she betrayed him to Crimson Dawn, Fett quickly rose in the ranks and became Jabba's favorite bounty hunter. After he was part of Nakano Lash's crew during the failed Corellian job in Star Wars: Bounty Hunters #1 by Ethan Sacks, Paolo Villanelli, Arif Prianto, and Travis Lanham, Boba spent the majority of his time by Jabba's side. It seems the only time he left Jabba's Palace was to run missions for the crime lord.
As Jabba's favorite bounty hunter, Boba Fett was also considered the enforcer within the gangster's palace. The bounty hunter can be seen by Jabba's side in Star Wars: Galaxy's Edge #2 by Sacks, Will Sliney, Dono Sánchez-Almara, and Lanham when his employer met with fellow bounty hunter Greedo. Fett was also present for many subsequent meetings and would even accompany Jabba when he accosted Han Solo at the beginning of A New Hope. Things would eventually become more serious after Jabba loaned Fett out to Vader in Star Wars: Darth Vader #1 by Kieron Gillen, Salvador Larroca, Delgado, and Joe Caramagna.
Unfortunately for Fett, his loyalty to Jabba only got him so far in the end. After Han Solo's carbonite slab was stolen from him on Nar Shaddaa, the Hutt gangster wasted no time putting out a bounty on his former favorite hunter. This has clearly upset the bounty hunter and he has now made it his mission to reclaim Solo for his own and clear his name. Unfortunately, Fett is not the only one trying to reclaim Solo as he will have to go against the Empire and even the Hutts to retrieve the smuggler and restore his status.