Mr Alfred John Alexander Podesta, better known as John or colloquially as Jack, was born at Bevois Road in Southampton, Hampshire, England on 14 September 1887.

He was the only child of Giovanni Podesta (b. circa 1830) and Mary Jane Light (b. circa 1858). His father, known in England as John, was Italian by birth whilst his mother was a native of Bransgore, Hampshire. They were married in October 1879 in South Stoneham, Hampshire. 

What became of John's father is not known and his mother was described as a widow when they appeared on the 1891 census whilst boarding at 14 St George's Place, Southampton. 

In 1893 Mary Podesta remarried to William Thomas Smith (1852-1902), a gas works labourer; three years previous in 1890 they had welcomed a daughter, Mary. 

By 1911 John Podesta was still at home with his then-widowed mother, then at 21 Chantry Road, Southampton. He was described as a fireman in the merchant service and also residing at the address was his fiancée Daisy Florence Chives (b. 3 August 1888), a fruit packer and fellow-native of Southampton. 

When he signed-on to the Titanic on 6 April 1912 Podesta gave his address as 21 Chantry Road, Southampton. He had transferred from the Oceanic and as a fireman received monthly wages of £6.

On the morning of 10th April Podesta together with his watch-mate William Nutbean, fellow firemen Alfred, Bertram and Thomas Slade and trimmer Penney, who lodged with the Slade brothers were all still sitting in a Southampton pub. Podesta recalled:

I got up on the morning of April 10th and made off down to the ship for eight o'clock muster, as is the case on all sailing days, which takes about an hour. As the ship is about to sail at about twelve o'clock noon most of us firemen and trimmers go ashore again until sailing time. So off we went [with] several others I knew on my watch, which was 4 to 8. My watch-mate, whose name was William Nutbean and I went off to our local public-house for a drink in the Newcastle Hotel. We left about eleven fifteen making our way toward the docks. Having plenty of time we dropped into another pub called the Grapes, meeting several more ship-mates inside. So having another drink about six of us left about ten minutes to twelve and got well into the docks and toward the vessel. With me and my mate were three brothers named Slade: Bertram, Tom and Alfred.

We were at the top of the main road and a passenger train was approaching us from another part of the docks. I heard the Slades say, "Oh, let the train go by". But me and Nutbean crossed over and managed to board the liner. Being a long train, by the time it passed, the Slades were too late, and the gangway was down leaving them behind. So it seemed they did not have to go.

The officer in charge of the gangway heard the men call out, but knew that there were extra men waiting on board for just this opportunity and so, even though he could have waited, he ordered the gangway lowered and signed on the extras.

Podesta saw the New York incident take place, and was also present on deck when John Coffee deserted the ship at Queenstown (in order to visit his mother.)

On 14 April  Podesta and William Nutbean went off duty at 8 pm and later had supper in the mess room. As they left the mess they could hear the ship's lookouts cry "Ice ahead, sir!" Podesta and Nutbean then went out on deck to look around, but saw nothing. They went back inside and down to their bunkroom, where they talked together for a little while before turning in. (Podesta later said that the lookouts repeated their ice warnings to the bridge several times, but to no avail.) A short time later the collision occurred Podesta and Nutbean tried unsuccessfully to get other crewmen out of bed, but soon Boatswain Nicholls came in and ordered everyone to their boat stations. Podesta and Nutbean went on deck and helped to lower lifeboat 7. Later Murdoch told the two men to lower themselves down the falls into a lifeboat (Stringer, 2003, suggests it was collapsible D), after which he ordered the boat to remain close by in case it had to return to the ship. The boat was 500 yards from the ship when she went down. The boat was later picked up by the Carpathia, and Podesta and Nutbean did their best to help revive some of their half-frozen mates. The surviving crewmen later returned to England on the Lapland.

John Podesta resided in Southampton for the rest of his life. In 1913 he and Daisy Florence Chives were wed, later settling at 5 Marine Parade, Chapel, Southampton. The couple would have no children.

Podesta continued serving at sea; following the outbreak of war in Europe, in August 1914 he volunteered for merchant war service and served aboard the ships HMH Salta and HMH St Andrew. He also served aboard transport ships HMT Campanello and HMT Devon in several dangerous theatres of war including the evacuation of Gallipoli. He was aboard HMT Ariosto when she was engaged with an enemy submarine. He was described as standing at 5' 6" and with auburn hair, blue eyes and a fair complexion and also had tattoos on the back of both hands. 

During the war Podesta found himself at odds with maritime law: in January 1915 he and six other firemen were charged with neglect of their duties and impeding the journey of the troopship (unidentified) they were serving aboard. The ship's master, Captain Roberts, stated that the men were due to join the ship in Southampton one afternoon but none arrived on time. One arrived late and another two even later than that, one of them being intoxicated. The seven men were sentenced to twelve weeks hard labour. 

Despite this setback, Podesta was demobilised in March 1920 and garnered the General Service and Mercantile Marine War Medals. 

He later left the sea but continued to work in the docks as a fitter's mate; by 1939 he and his wife Mabel were residing at 27 Paget Street, Southampton. He retired from his final job at Camper & Nicholson's of Northam in Southampton in 1958 aged 70 and enjoyed a few years of rest with his wife Mabel until her death in 1964.

In early 1966 a vacation to Bournemouth with the Southampton Lions Club had an unanticipated turn for John. That organisation had planned a vacation for group of 150 pensioners for a Bournemouth-bound holiday and one other punter on that trip was Helen Diaper (née Thomas), known as Nelly, a former employee of Toogoods in Southampton. She was born 7 June 1894 and was a childless widow after her husband Ernest Henry Diaper, a labourer, having died in 1961.

Later that year in October 1966, with John being 79 and Nelly 72, both were bride and groom again. Initially making their home at Bonchurch Way, Swaythling, Southampton, in 1967 both moved to a new flat (#14) in Curzon Court, Lordswood, Southampton where John spent the rest of his days.

John and his new wife were married less than two years when he died on 13 May 1968 at the age of 80 in the Southampton General Hospital. He was buried in South Stoneham Cemetery, Southampton (section P3, plot 26). His widow Helen died on 3 May 1975, also aged 80.