Let me be of assistance here, please.
EF Indonesia, depending upon which EF group, is actually a slight cut above EF in China, a big slight cut.
But it depends upon the group.
There is the EF Indonesia Group that does Djakarta and that part of the country (I can't remember the name of it) and the EF Indonesia Group that does parts of the country like Bali, and the No. 2 Indonesian city (again excuse me but I can't remember the name).
At one point in time, I was thinking of Indonesia and I applied to both. I flew down to look over the country and the schools. Djakarta was terrible -- Shenzhen maybe even worse. But the No. 2 city and the rest of the country had a great deal of charm, with certain limitations.
If you are considering EF Swara (which I think is the Djakarta one), I would suggest that you avoid it. Djakarta by all standards is an extremely big, and seriously dangerous, city. Surabaya (I just remembered it) is the second-largest city in the country (and I visited it) and the city and the area around it have a great deal of charm, a great, great deal of charm. If it is the EF Surabaya group that are considering you, I would decidedly take it with one CAVEAT.
TRY TO OBTAIN A HOUSING ALLOWANCE. The communal house that they put at your disposition is nothing more than one huge, large frat house. Parties round the clock and people coming and going at all hours. FT's that live in the house generally survive one year only; FT's that had moved outside of the house had stayed 2 - 3 years.
The weather in Surabaya is quite tropical and flooding is NOT uncommon. The city is 1,000% times safer than Djarkata and you should be warned that it is a decidedly Muslim conservative city in all aspects. The local were exceptionally charming, that is for sure. I would take the job for sure. You will be able to save some money plus you will be really able to enjoy a nice part of the country.
Finally, stay off Indonesian inter-island ferries at all costs unless you are an Olympic swimmer in shark-infested waters. Next, Indonesian local airline carriers have a terrible, terrible safety record and GARUDA, the national carrier, was, until quite recently, banned from flying to the EU. I believe that it may still be banned from flying to the US.
You need to exercise a great, great deal of caution in your travel arrangements, less so, however, in your daily living conditions.